Indicating apparatus and method with pointer

Abstract: A current measured value measured by measuring means (37) is indicated by a measured value pointer (28). A maximum or minimum pointer (30) is interlocked with the measured value pointer and moves only in an incremental or decremental direction to indicate the maximum or minimum value. Therefore, a current measured value and the maximum or minimum value can be indicated simultaneously using a single drive source (105).

Description: The present invention relates to an apparatus and a method for indicating measurements with an analog display and a pointer unit thereof. Such an apparatus may include depth meter, barometers, altimeters, thermometers and other meters in which the maximum or minimum value can be indicated with a current measured value. For example, a diver's depth meter is known which has a pointer indicating a current depth of a diver and a maximum value pointer indicating the maximum depth of the diver during the measurement. Such a depth meter comprises a motor for rotatably driving the pointer and another motor for rotatably driving the maximum value pointer. The motor for the maximum value pointer stops when the maximum value pointer is at a position of the maximum depth during the measurement to stop the maximum pointer. In the conventional analog display measuring instrument which stores and indicates the maximum or minimum measured value and the computed result of the measurements such as an average value, the pointers are respectively driven by drives independent from each other even if the maximum or minimum measured value and the computed result are indicated on the same dial. Before the measurement begins, the conventional analog display measuring instrument can not perform the indication or indicate only zero or a preset minimum value. In the conventional analog display measuring instrument which indicates a plurality of measured values or a plurality of data computed from these measured values, no sound or only one kind of confirmation sound is produced to notify indication of data. In the conventional analog display measuring instrument which performs the measurement in a fixed cycle, when the motion of the pointer does not terminate in the cycle, the pointer continues indicating while next measurement is carried out, or the pointer temporarily stops indicating during the measurement. In such a conventional analog display measuring instrument, measuring is forcedly suspended by an operation such as simultaneous pushing of switch buttons. These analog display measuring instruments such as a depth meter will be increased in manufacturing cost since they utilize two different motors for driving the current measured value pointer and maximum value pointer, respectively. If a single drive motor is used to drive both pointers and if the maximum value pointer is made to stay at a position of the maximum value, the number of the motors can be reduced to lower the manufacturing cost. US 4196690 discloses a device for indicating the maximum reading of a measuring instrument including a rotatable main needle for indicating the current reading of the instrument. An auxiliary needle for indicating the maximum reading is provided with an engagement means by which it is engaged by the main needle on advancing movement. As the main needle returns to zero, the auxiliary needle remains at the maximum position reached. DE 0157834 C discloses a barometer comprising a measured value pointer and a maximum value pointer. The maximum value pointer is provided with a pawl, which engages with the teeth of a ratchet wheel provided on the measured value pointer such that the maximum value pointer is driven in one direction only. In such cases, however, the maximum value pointer must be subjected to a large load for preventing it from being undesirably displaced from the proper position due to vibration or impact. At this time, the current measured value pointer must also be loaded while being driven. This will increase the power consumption. The conventional analog display measuring instrument which stores and indicates the maximum or minimum value of the measurements and the computed result of measurements such as an average value needs a number of drive sources because the pointers are driven independently even if the maximum or minimum value and the computed value are indicated on the same dial. Since the conventional analog display measuring instrument which stores and indicates the current measured value and associated data indicates nothing or a variable or zero value or a minimum measurable value before measuring, one cannot confirm whether or not the indication function can be properly performed, and cannot execute the indication function for learning or explaining the operational manner until the measurement is executed. Since the conventional analog display measuring instrument which indicates the current measured value and the maximum or minimum measured value does not indicate time information simultaneously, an elapsed time since initiation of the measurement cannot be indicated. Since the conventional analog display measuring instrument which stores and indicates the maximum or minimum measured value and the computed result of measurements such as an average value does not indicate time information simultaneously, an elapsed time since initiation of the measurement cannot be indicated. Since the conventional analog display measuring instrument which indicates the current measured value and the maximum or minimum measured value does not indicate time information simultaneously, an initiation time of measurement cannot be indicated. Since the conventional analog display measuring instruments which stores and indicates the maximum or minimum measured value and the computed result of measurements such as an average value does not indicate time information simultaneously, an initiation time of measurement cannot be indicated. When it is wanted to provide a maximum value indicating pointer movable only in an incremental direction or a minimum value pointer movable only in a decremental direction in synchronization with motion of the current measured value pointer, if there is not means for automatically return the current measured value pointer to a home position together with the maximum or minimum value pointer, the pointers have to be returned manually. Since the conventional analog display measuring instrument which indicates a plurality of measured values or a plurality of data computed from these measured values generates no confirmation sound or only one kind of confirmation sound on calling the data, the user must count the number of operations for data calling to know which data is called. The conventional analog display measuring instrument which indicates a plurality of measured values or a plurality of data computed from these measured values does not have a function of returning the indication to its normal state through the same means for data calling after all the data of measured values have been called. Therefore, a special operation is required to return the indication to its normal state. In the conventional analog display measuring instrument which performs the measurement in a fixed cycle, when the motion of the pointer does not terminate in the cycle, the pointer continues indicating while next measurement is carried out, or the pointer temporarily stops indicating during the measurement. This raises various problems in that noises providing an improper measurement may be produced when the pointers are driven, in that the capacity of the power source becomes insufficient due to the simultaneous execution of both the drive and measurement and in that the movement of the pointers is delayed relative to the measurement. Since the conventional analog display measuring instrument which performs the measurement in a fixed cycle may be forcedly suspended from measuring by an operation such as simultaneous pushing of switch buttons, a wrong operation can be undesirably made to stop the measurement. It is therefore a primary object of the present invention to provide an analog display measuring instrument and its pointer unit which can only use a single drive source for driving the measured value pointer and the maximum or minimum value pointer to suppress the manufacturing cost and also to provide an analog measuring instrument and its pointer unit which can prevent an undesirable displacement of the maximum or minimum value pointer due to vibration, impact or the like without addition of any great load thereon. Another object of the present invention is to reduce the number of necessary drive sources by performing the indication of the maximum or minimum value through a maximum value pointer movable only in an incremental direction or a minimum value pointer movable only in a decremental direction in synchronization with motion of a measured value pointer. Still another object is to provide an analog display measuring instrument which can execute the normal indication even if the measurement has not been performed. A further object is to provide an analog display measuring instrument which can indicate a measured value and the maximum or minimum value and also show an elapsed time from initiation of the measurement through a time information pointer. A still further object is to an analog display measuring instrument which can indicate the maximum or minimum value of measured values, the average value and the computed result of measurement and also show an elapsed time from initiation of the measurement through a time information pointer. A further object is to provide an analog display measuring instrument which can indicate a measured value and the maximum or minimum value and also show a time when the measurement is initiated through a time pointer. A further object is to provide an analog display measuring instrument which can indicate the maximum or minimum value of measured values, the average value and the computed result of measurement and also show a time when the measurement is initiated through a time pointer. A further object is to provide an analog display measuring instrument which can easily return a maximum or minimum value pointer to its home position. A further object is to provide an analog display measuring instrument which generates a confirmation sound corresponding to data called by a user for informing the type of the data by the type or the number of the sound. A further object is to provide an analog display measuring instrument which can simply return the indication to its normal state merely by continuing the same operation as in the calling of data. A further object is to provide an analog display measuring instrument which can suspend the measurement to prevent it from being inaccurately executed due to noises produced when the pointers are driven until the pointer shows a measured value and which can maintain the capacity of a power source sufficient during the simultaneous execution of pointer drive and measurement with less delay in the indication by the pointer. A further object is to provide an analog display measuring instrument which forcedly stops the measurement by operating switches interlocked with a crown to prevent mistaken interruption of the measurement. The present invention provides a pointer unit for use in an analog display measuring instrument comprising a measured value pointer for indicating a current measured value and a maximum or minimum value pointer to be placed at the maximum or minimum measurement position for indicating the maximum or minimum value, said measured value pointer being connected to a drive source, characterised in that said maximum or minimum value pointer is interlocked with said measured value pointer and further comprising a control cam for stopping said maximum or minimum value pointer at a position of the maximum or minimum value during measurement. In another aspect the present invention provides an analog display measuring instrument comprising: a pointer unit as set out above and further comprising; a gear train for driving said measured value pointer; said drive source driving said gear train; and a control means for controlling said drive source to move said measured value pointer to a position corresponding to a measured value obtained by a measuring means. According to the present invention, the analog display measuring instrument indicating a measured value and the maximum or minimum value can drive both the measured value pointer and maximum or minimum value pointer through a single drive source. Thus, the analog display measuring instrument can be simplified in structure and reduced in size and cost. Since the number of drive sources occupying a relatively large volume is reduced, designing can be done more easily and freely. The analog display measuring instrument further comprises: an input means being able to select a first or second indication mode; a maximum or minimum value storage means for storing the maximum or minimum value among values measured by the measuring means; a computation means for performing a specific computation relative to a value measured by the measuring means; and a computation result storage means for storing a computed result; wherein the control means controls the drive source to move the measured value pointer to a position corresponding to a value measured by the measuring means when the first indication mode is selected by the input means, or to a position corresponding to the maximum or minimum value stored in the maximum or minimum value storage means and then to a position corresponding to a computed result stored in the computation result storage means when the second indication mode is selected by the input means, whereby values respectively stored in the maximum or minimum value storage means and computation result storage means can be simultaneously indicated. The computation means may compute an average value. In an analog display measuring instrument which stores and indicates the maximum or minimum measured value, the average value and the computed result of measurement, both the maximum value pointer and measured value pointer can be driven by a single drive source. Thus, the analog display measuring instrument can be simplified in structure and reduced in size and cost. Since the number of drive sources occupying a relatively large volume is reduced, designing can be done more easily and freely. The analog display measuring instrument further comprises: a timer means for measuring an elapsed time; a time information pointer for indicating time information obtained by the timer means; a second gear train for driving the time period information pointer; and a second drive source for driving the second gear train; wherein the control means controls the second drive source to move the time information pointer to a position corresponding to a time measured by the timer means, whereby a measured value by the measuring means can be simultaneously indicated with time information from the timer means. In the analog display measuring instrument for indicating a measured value and the maximum or minimum value, therefore, an elapsed time from initiation of the measurement can be indicated. Thus, the user can easily know the time information. The analog display measuring instrument may be more broadly used in various fields. The analog display measuring instrument further comprises: a timer means for measuring an elapsed time; a time information pointer for indicating time information obtained by the timer means; a second gear train for driving the time information pointer; a second drive source for driving the second gear train; and a time information storage means for storing time information obtained by the timer means; wherein the control means controls the second drive source to move the time information pointer to a position corresponding to a value stored in the time information storage means when the second indication mode is selected by the input means, whereby the maximum or minimum value stored in the maximum or minimum value storage means, a value stored in the computation result storage means, and time information stored in the time information storage means can be simultaneously indicated. In the analog display measuring instrument which stores and indicates the maximum or minimum measured value, the average value and the computation result of measured values, therefore, the time information can also be stored and indicated. The user can easily know the time information in addition to the maximum or minimum value and computation result. The analog display measuring instrument may be more broadly used in various fields. The analog display measuring instrument further comprises: a time measuring means for measuring a present time; a time pointer for indicating a present time measured by the time measuring means; a third gear train for driving the time pointer; and a third drive source for driving the third gear train; wherein the control means controls the third drive source such that a present time measured by the time measuring means is indicated by the time pointer when the measuring means is not in operation, and a time at which the measuring means has started measuring is indicated when the measuring means is in operation. In the analog display measuring instrument which indicates a measured value and the maximum or minimum value, therefore, time information can be also indicated. The user can easily know time information in addition to the maximum or minimum value and computation result. The analog display measuring instrument may be more broadly used in various fields. The analog display measuring instrument further comprises: a time measuring means for measuring a present time; a time pointer for indicating a present time measured by the time measuring means; a third gear train for driving the time pointer; a third drive source for driving the third gear train; and a measurement initiation time storage means for storing a time of measurement initiation of the measuring means; wherein the control means controls the third drive source to move the time pointer to a position corresponding to a time stored in the measurement initiation time storage means when the second indication mode is selected by the input means, whereby the maximum or minimum value stored in the maximum or minimum value storage means, a value stored in the computation result storage means, and a time stored in the measurement initiation time storage means can be simultaneously indicated. In the analog display measuring instrument which stores and indicates the maximum or minimum measured value, the average value and the computation result of measured values, therefore, the measurement initiation time can also be indicated. The user can easily know the time information. The analog display measuring instrument may be more broadly used in various fields. When an initializing means is provided which causes the maximum or minimum value storage means, computation result storage means, time information storage means and measurement initiation time storage means and others to store specific values, the analog display measuring instrument for indicating the measured values and associated data can execute the normal indication even if the measurement has not still been started. Thus, the user can confirm whether or not the indication function is normally executed even when the measurement is not made. Furthermore, the user can learn or explain the operational manner even if the measurement has not been made. This is particularly effective in the depth meter or other meters in which it is difficult to execute their measuring function in the normal state. The analog display measuring instrument further comprises a home position setting means for returning the measured value and maximum or minimum value pointers to a home position, wherein the control means controls the home position setting means to operate the drive source to move the measured value and maximum or minimum value pointers to the home position. In the analog display measuring instrument which includes the maximum or minimum value pointer movable only in the incremental or decremental direction in synchronization with motion of the measured value pointer, the measured value and maximum or minimum value pointers can be automatically returned to the home position together. Therefore, the operation for returning the maximum or minimum value pointer to the home position can be simplified to improve the operability greatly. In the analog display measuring instrument, the input means selects one of various types of second indication modes to indicate data stored in the maximum or minimum value storage means or the computation result storage means; and the maximum or minimum value storage means or the computation result storage means is selected by selecting one of the second indication modes by the input means to move the measured value pointer to a position corresponding to a measured value stored in a selected storage means; the analog display measuring instrument further comprising confirmation sound generating means for generating a confirmation sound when one of the second indication modes is selected by the input means and a confirmation sound control means for causing the confirmation sound generating means to generate a type of sound corresponding to the second indication mode selected by the input means. In the analog display measuring instrument which indicates a plurality of measured values or a plurality of data computed from the measured values, therefore, a type of sound corresponding to the called data can be generated such that the user can easily confirm what data is called. Thus, the operation of confirming the called data can be simplified to improve the operability greatly. In the analog display measuring instrument, the input means selects one of the second indication modes for the maximum or minimum value or computation result storage means depending on the number of inputs; the control means controls the drive source depending on the number of inputs from the input means to move the measured value pointer to a position corresponding to a measured value stored in selected storage means; and the control means controls the drive source to move the measured value pointer to a position of the measured value when the number of inputs from the input means exceeds a set number. In the analog display measuring instrument which indicates a plurality of measured values or a plurality of data computed from the measured values depending on the number of inputs, therefore, the indication can be easily returned to the normal state merely by continuously performing the same operation as in the data calling operation. Therefore, the operation of returning the indication to the normal state after calling of the data can be simplified to improve the operability greatly. The analog display measuring instrument further comprises an operation discriminating and controlling means for suspending an operation of the measuring means until the measured value pointer shows a result of preceding measurement. Thus, the measurement can be prevented from being inaccurately performed due to noises generated when the measured value indicating pointer is being driven while power insufficiency due to movement of the measured value pointer together with next measurement can be also prevented. Moreover, time required to move the measured value pointer can be reduced. A delay of indication, which is a shortcoming in the conventional analog display measuring instruments, can be improved to increase the quality in the analog display measuring instrument. The analog display measuring instrument further comprises a crown input means interlocked with a crown and an input control means for stopping an operation of the measuring means when there is an input from the crown input means. In the analog display measuring instrument, the crown is of a screw lock type. Thus, the measurement can be prevented from being interrupted by an unintentional operation. In the analog display measuring instrument, the measuring means measures any one of depth of a diver, atmospheric pressure, temperature and altitude. Thus, the analog display measuring instrument can indicate the measured depths of a diver, atmospheric pressures, temperatures or altitudes with their maximum or minimum value by a single drive source. Since measured value pointer can rotate accompanied by the maximum or minimum value pointer by a single drive source, the number of drive sources can be minimized to reduce the manufacturing cost. The pointer unit in the analog display measuring instrument further comprises: a measured value indicating wheel rotatably connected to the drive source for rotating the measured value pointer; a maximum or minimum value indicating wheel for rotating the maximum or minimum value pointer; said control cam stopping the maximum or minimum value indicating wheel at the maximum or minimum measurement position according to rotation of the measured value indicating wheel to stop said maximum or minimum value pointer; and a keep plate engageable with the control cam for stopping the control cam; wherein the measured value indicating wheel includes means for driving and stopping the control cam; the maximum or minimum value indicating wheel includes a cam engagement which engages with the control cam in a rotational direction of the maximum or minimum value indicating wheel and enables the control cam to slide in a diametric direction of the maximum or minimum value indicating wheel, and cam bias means for biasing the control cam in the diametric direction; the control cam includes a mesh portion engageable with the keep plate to stop the maximum or minimum value indicating wheel ; and the keep plate includes another mesh portion formed therein at a position opposite to the mesh portion of the control cam and engageable with the mesh portion of the control cam. Thus, the control cam can be rotated in association with rotation of the measured value indicating wheel while the measured value indicating wheel can be solely returned to the home position. The engaging portion of the control cam can be engaged with the cam engagement of the maximum or minimum value indicating wheel. Therefore, the rotation of the control cam can be accompanied by the maximum or minimum value indicating wheel. When the measured value indicating wheel is returned to the home position, the maximum or minimum value indicating wheel can remain at its position after movement. As a result, by a single drive source, the measured value indicating wheel can rotate accompanied by the maximum or minimum value indicating wheel and the maximum or minimum value indicating wheel can stop at its maximum or minimum measurement position in a reliable manner. In the pointer unit in the analog display measuring instrument, the measured value indicating wheel comprises an annular rotation slit having non-connected ends and functioning as a driving and stopping means for the control cam and a groove portion formed therein at at least one end for releasing the control cam from stoppage; and the control cam including a rotary guide pin which is fitted in the rotation slit to engage with the measured value indicating wheel in a given direction, engagement means which rotatably engages with the cam engagement and slides in the diametric direction of the maximum or minimum value indicating wheel and a contact portion brought into contact with the cam bias means to receive biasing force; the mesh portion of the control cam being formed on the outer periphery of the control cam at a position opposite to the contact portion. Thus, the engaging portion of the control cam which causes the rotary guide pin to engage with the rotation slit and control cam releasing groove portion of the measured value indicating wheel can be engaged with the cam engagement of the maximum or minimum value indicating wheel to be slidable in the diametrical direction. The control cam can be biased diametrically and outwardly by the cam bias means to engage or disengage the mesh portion of the control cam with the mesh portion of the keep plate through the groove portion of the measured value indicating wheel. Therefore, the maximum or minimum value indicating wheel can be placed at the maximum or minimum measurement position at all times without application of a rotation load. When the drive source is a motor, less load may be applied to the motor to reduce the power consumption since the cam bias means requires only a small load. Since the maximum or minimum value indicating wheel is positioned by engagement of the control cam with the keep plate, it can be reliably made. Even if a vibration is applied to these components, a shift can be positively prevented. In the pointer unit in the analog display measuring instrument, the groove portion formed in the rotation slit for releasing the control cam from stoppage has a sloped bias portion for biasing the rotary guide pin of the control cam in the outward direction. When the mesh portion of the keep plate is engaged with the mesh portion of the control cam, thus, this can be reliably made at the maximum or minimum measurement position without rotational deviation in the control cam. In the pointer unit in the analog display measuring instrument, one of opposed surfaces of the maximum or minimum value indicating wheel and control cam includes a plurality of projections formed therein for preventing close contact of the maximum or minimum value indicating wheel with the control cam. Thus, the control cam can be easily slid relative to the maximum or minimum value indicating wheel in the diametrical direction. As a result, the mesh portion of the control cam can be easily engaged or disengaged with the mesh portion of the keep plate. In the pointer unit in the analog display measuring instrument, the mesh portion of the keep plate includes a plurality of teeth formed therein and equidistantly spaced away from one another and wherein the mesh portion of the control cam also includes teeth each of which outwardly or inwardly engages with any adjacent two teeth in the mesh portion of the keep plate. Thus, the keep plate can be easily manufactured while securing the engagement for every one pitch. This can reduce the manufacturing cost. The indexing and position around the periphery of the control cam can be more finely made by less teeth. In the pointer unit in the analog display measuring instrument, the groove portion formed in the rotation slit of the measured value indicating wheel for releasing the control cam from stoppage includes jam preventing means for preventing a jam produced when the control cam engages with the keep plate. Thus, the control cam can be smoothly engaged with the keep plate. The number of working steps can be reduced to lower the manufacturing cost with improvement of the working accuracy. According to still another aspect of the invention, there is provided, a method for indicating measurements with an analog display which performs measuring by a measuring means, moves a measured value pointer by a drive source through a gear train to indicate a value measured by said measuring means, and moves a maximum or minimum value pointer to indicate the maximum or minimum value measured by said measuring means, comprising the steps of: controlling said drive source through a control means to move said measured value pointer to a position corresponding to a value measured by said measuring means; and characterised by interlocking said maximum or minimum value pointer with said measured value pointer such that said maximum or minimum value pointer is moved only in an incremental or decremental direction; and operating a control cam for stopping said maximum or minimum value pointer. The method for indicating measurements with an analog display further comprises the steps of: storing the maximum or minimum value among values measured by the measuring means in a maximum or minimum value storage means; performing a specific computation relative to a value measured by the measuring means using a computation means; and storing a computation result in a computation result storage means; wherein the control means controls the drive source to move the measured value pointer to a position corresponding to a value measured by the measuring means when a first indication mode is selected by an input means which can select a first or second indication mode, or to a position corresponding to the maximum or minimum value stored in the maximum or minimum value storage means and then to a position corresponding to a computed result stored in the computation result storage means when the second indication mode is selected by the input means, whereby values respectively stored in the maximum or minimum value storage means and computation result storage means can be simultaneously indicated. The method for indication measurements with an analog display further comprises the steps of: measuring an elapsed time by a timer means; and controlling a second drive source by the control means to move a time information pointer to a position corresponding to an elapsed time measured by the timer means through a second gear train, whereby a value measured by the measuring means can be simultaneously indicated with time information from the timer means. The method for indicating measurements with an analog display further comprises a step of controlling a third drive source by the control means for driving a time pointer through a third gear train such that a present time measured by a time measuring means is indicated when the measuring means is not in operation, and a time at which the measuring means has started measuring is indicated when the measuring means is in operation. The method for indicating measurements with an analog display further comprises the steps of: detecting a current position of the measured value pointer by a home position setting means; and controlling the home position setting means to move the measured value and maximum or minimum value pointers to the home position by the control means. The method for indicating measurements with an analog display further comprises the steps of: discriminating whether or not the drive source is in operation by a discriminating and controlling means after measurement is initiated; and suspending an operation of the measuring means until the measured value pointer shows a result of preceding measurement when the drive source is in operation. The method for indicating measurements with an analog display further comprises a step of stopping an operation of the measuring means by an input control means when the input control means receives an input from a crown input means interlocked with a crown. This method can provide the same results as in the aforementioned analog display measuring instruments. Examples of apparatus embodying the invention will now be described with reference to the accompanying diagrammatic figures, in which; Fig. 1 is a front view of a diver's watch which uses a pointer unit according to one embodiment of the present invention. Fig. 2 is a partial cross-section of Fig. 1 Fig. 3 is a plan view showing the pointer unit of Fig. 2 in its start position. Fig. 4 is a plan view showing the pointer unit of Fig. 3 when the diver dives in the water. Fig. 5 is a plan view showing the pointer unit when the diver goes up from the position of Fig. 4. Fig. 6 is a plan view showing the pointer unit of Fig. 5 when the diver surfaces. Fig. 7 is a plan view of a measured value indicating wheel. Fig. 8 is a plan view of a maximum value indicating wheel. Fig. 9 is a plan view of a control cam. Fig. 10 is a plan view of a keep plate. Fig. 11 illustrates another embodiment of the present invention. Fig. 12 is a hardware diagram of one embodiment of an analog display measuring instrument constructed in accordance with the present invention. Fig. 13 is a block diagram of the analog display measuring instrument shown in Fig. 12 with a memory. Fig. 14 is a block diagram of another embodiment of an analog display measuring instrument constructed in accordance with the present invention with a memory, having functions of a memory recall and a memory recall confirmation sound. Fig. 15 is a block diagram of still another embodiment of an analog display measuring instrument constructed in accordance with the present invention, including a function of initializing the stored value. Fig. 16 is a block diagram of still another embodiment of an analog display measuring instrument constructed in accordance with the present invention, including a means for returning the maximum and measured value pointers to the home position. Fig. 17 is a flowchart of the analog display measuring instrument shown in Fig. 13. Fig. 18 is a flowchart of the analog display measuring instrument shown in Fig. 14. Fig. 19 is a flowchart of the analog display measuring instrument shown in Fig. 15. Fig. 20 is a flowchart of the analog display measuring instrument shown in Fig. 16. Various preferred embodiments of the present invention will now be described with reference to the drawings. Figs. 1 to 10 show one embodiment of a diver's watch depth meter to which a pointer unit of an analog display measuring instrument of the present invention is applied. As shown in Fig. 1, the diver's watch of this embodiment can function as a conventional watch which comprises hour and minute hands 10, 12 centrally disposed thereon and a 24-hour hand 14, a small second hand 16, an alarm hour hand 18, an alarm minute hand 20 and a date indicator 22, these components being disposed around. The watch also includes a diving time pointer 24 which is centrally disposed on the watch and functions as a time information pointer. The watch further includes a one-tenth meter pointer 26, a depth pointer 28 functioning as a current measured value pointer and a maximum depth pointer 30 functioning as a maximum value pointer, these pointers composing a depth meter. The one-tenth meter pointer 26 makes one revolution for every one meter depth. Each time when the one-tenth meter pointer 26 makes one revolution, the depth pointer 28 rotates one minute to indicate the current measured value. The maximum depth pointer 30 rotates with rotation of the depth pointer 28 and stops at a position of the maximum value recorded during the measurement. Thus, the information of diving including the diving time, current depth and maximum depth can be provided by the diving time pointer 24, depth pointer 28, one-tenth meter pointer 26 and maximum depth pointer 30. The alarm hour and minute hands 18, 20 forms a time indicator which can indicate a diving start time and warn against a high-speed surfacing. Reference numerals 32, 34 and 35 denote buttons. 34 designates a button interlocked with a push switch B (PSW-B) 915 shown in Fig. 12. 37 is a water sensing switch and 39 and 41 are screw lock type crowns, these switch and crowns functioning in the well-known manner. A pointer unit comprising the depth and maximum depth pointers 28, 30 that form a depth meter will be described mainly with reference to Figs. 2 and 3. The pointer unit comprises a measured value indicating wheel 36 connected to the depth pointer 28, a maximum value indicating wheel 38 connected to the maximum depth pointer 30, a control cam 40 connecting the measured value indicating wheel 36 with the maximum value indicating wheel 38 to be interlocked with each other, and a keep plate 42 for stopping the control cam 40. The measured value indicating wheel 36 is connected to a motor (not shown) functioning as a drive source through gears 44 and 46. The measured value indicating wheel 36 is reversibly rotated by the motor, and the depth pointer 28 is also reversibly rotated through reversible rotation of the measured value indicating wheel 36. As shown in Fig. 7, the measured value indicating wheel 36 includes an annular rotation slit 48 having opposite non-connected ends. Groove portions 50 are formed in the rotation slit 48 at the opposite ends thereof for releasing the control cam 40 from stoppage. The rotation slit 48 has a width slightly larger than the diameter of a rotary guide pin 64 (which will be described) in the control cam 40. Each of the groove portions 50 extends inwardly substantially toward the center of the measured value indicating wheel 36 and has an inner side that forms a sloped bias portion 52 for outwardly biasing the rotary guide pin 64 of the control cam 40. The maximum value indicating wheel 38 is disposed below the measured value indicating wheel 36 and is independently rotatable on the same axis as that of the measured value indicating wheel 36. The rotation of the maximum value indicating wheel 38 rotates the maximum depth pointer 30. As shown in Fig. 8, the maximum value indicating wheel 38 includes a cam engagement 54 formed to protrude from the top and central face thereof and adapted to engage the control cam 40 and a leaf spring 56 on the top of the wheel 38 adjacent the outer periphery thereof and functioning as cam bias means for outwardly biasing the control cam 40 in the diametrical direction. The cam engagement 54 has flat slide sides 58 formed therein parallel to each other. The leaf spring 56 has one end attached to the maximum value indicating wheel 38 through a support block 60. When the support block 60 is adjusted in angle, the biasing force of the leaf spring 56 to the control cam 40 can be adjusted. The top face of the maximum value indicating wheel 38 includes a plurality of projections (three in this embodiment) 62 for preventing the maximum value indicating wheel 38 from being brought into intimate contact with the control cam 40. The control cam 40 is disposed between the measured value indicating wheel 36 and the maximum value indicating wheel 38 and adapted to rotatably drive the maximum value indicating wheel 38 in the incremental direction through rotation of the measured value indicating wheel. The control cam 40 is further adapted to position the maximum value indicating wheel 38 at the maximum measurement position. As shown in Fig. 9, the control cam 40 is in the form of an annular plate which has its opposite non-connected ends and comprises a rotary guide pin 64 functioning as control cam driving/positioning means, engagements 66, a contact portion 68 and a mesh portion 70. The rotary guide pin 64 is formed on the top face of the control cam 40 adjacent one end at a position opposite to the rotation slit 48 of the measured value indicating wheel 36. When the rotary guide pin 64 is inserted into the rotation slit 48 of the measured value indicating wheel 36 and engages into the groove portion 50 at the end of the rotation slit 48, the control cam 40 will be rotated as the measured value indicating wheel 36 is rotated in the incremental direction. The engagements 66 engage the slide sides 58 of the cam engagement 54 of the maximum value indicating wheel 38 at four points such that the control cam 40 can be rotatably driven with the maximum value indicating wheel 38 as a unit and can slide on the slide sides 58 in the diametrical direction. The contact portion 68 is formed on the inner end of the control cam 40 adjacent the rotary guide pin 64 and adapted to contact the free end of the leaf spring 56 on the maximum value indicating wheel 38 such that the control cam 40 is diametrically outwardly biased along the slide sides 58 of the cam engagement 54 under the influence of the leaf spring 56. The mesh portion 70 is formed on the outer periphery of the control cam at a position opposite to the contact portion 68 and adapted to position the control cam 40 at any rotational position. Thus, the maximum value indicating wheel 38 can be positioned in the same rotational direction as in the control cam 40. In this embodiment, the mesh portion 70 includes a pair of teeth 72 extending outwardly and spaced away from each other. The teeth 72 mesh with the keep plate 42. The keep plate 42 is in the form of an annular plate which is disposed at a position corresponding to the mesh portion 70 of the control cam 40 and includes an inner periphery having a mesh portion 74 adapted to engage the mesh portion 70 of the control cam 40, as shown in Fig. 10. The mesh portion 74 of the keep plate 40 includes 60 teeth 76 formed therein being thinned out for every one pitch. The pair of teeth 72 on the mesh portion 70 of the control cam 40 either outwardly engage two adjacent teeth 76 on the mesh portion 74 of the keep plate 42 or inwardly engage two outside teeth 76 of three adjacent teeth 76. Thus, the teeth 76 thinned out for every one pitch can be engaged by the teeth 72 of the control cam 40 for every one pitch. By thinning the teeth 76 of the keep plate 42 for every one pitch, the keep plate 42 can be easily manufactured to minimise the manufacturing cost. At the same time, the maximum value indicating wheel 38 can be positioned at any one of 120 indexed positions around the periphery of the keep plate 42 even if only 60 teeth are used in the keep plate 42. In Fig. 2, reference numeral 1 denotes a ground plate functioning as a base plate for holding various components in the watch, 2 a center wheel to which the minute hand is attached; 3 a center pipe fixedly mounted on the ground plate 1 and adapted to guide the second wheel 2; 4 an hour wheel to which the hour hand is attached; 5 a diving time indicating wheel to which the diving time indicating pointer is attached; and 6 a train wheel bridge for supporting the wheels. These components function in the well-known manner. The operation of the depth pointer indicator will be described mainly with reference to Figs. 3 to 6. In the start state as shown in Fig. 3, the rotary guide pin 64 of the control cam 40 engages into the groove portion 50 on the end of the rotation slit 48 in the measured value indicating wheel 36. The control cam 40 has been moved relative to the maximum value indicating wheel 38 against the biasing force of the leaf spring 56 such that the mesh portion 70 has been slid diametrically and inwardly along the slide sides 58 of the cam engagement 54 in the maximum value indicating wheel 38. Therefore, the mesh portion 70 of the control cam 40 does not engage with the mesh portion 74 of the keep plate 42. The control cam 40 is rotatable with the maximum value indicating wheel 38. When the diving is initiated at the state of Fig. 3, a rotational force is transmitted from the gears 46 and 44 shown in Fig. 2 to the measured value indicating wheel 36 which is in turn initiated to rotate from the state of Fig. 3, e.g., clockwise. Thus, the rotary guide pin 64 engages into the groove portion 50 of the measured value indicating wheel 36. Since the mesh portion 70 of the control cam 40 does not engage the mesh portion 74 of the keep plate 42, the control cam 40 is rotatably driven in the clockwise direction through the rotation of the measured value indicating wheel 36. The maximum value indicating wheel 38, which can be rotated with the control cam 40 as a unit through the cam engagement 54 and engagements 66, will also be rotated. As the diving is performed to a given depth, for example, such a state shown in Fig. 4 can be accomplished. As the diver begins to surface from the depth position shown in Fig. 4, the rotation of the gears 46 and 44 shown in Fig. 2 is reversed to rotate the measured value indicating wheel 36 in the counter-clockwise direction. This permits the rotary guide pin 64 of the control cam 40 engaged into the groove portion 50 of the measured value indicating wheel 36 to be biased diametrically outwardly in co-operation of the sloped bias portion 52 with the biasing force of the leaf spring 56. Thus, the engagements 66 of the control cam 40 are slid along the slide sides 58 formed on the cam engagement 54 of the maximum value indicating wheel 38 to move the control cam 40 on the maximum value indicating wheel 38. The mesh portion 70 of the control cam 40 moves diametrically and outward and engages the mesh portion 74 of the keep plate 42 to position the control cam 40. Therefore, the maximum value indicating wheel 38 rotated with the control cam 40 as a unit is also positioned. Such a positioning can be easily performed since the control cam 40 is diametrically outwardly biased under the action of the leaf spring 56 in the maximum value indicating wheel 38. In addition, the positioning can be accurately made under the action of the sloped bias portion 52 without deviation. Since the control cam 40 is prevented from being brought into intimate contact with the maximum value indicating wheel 38 by the projections 62 in the maximum value indicating wheel 38, the sliding will be positively performed. As the diver has surfaced from this state to some depth, the rotary guide pin 64 of the control cam 40 is moved into the rotation slit 48 of the measured value indicating wheel 36. Therefore, the measured value indicating wheel 36 will only be rotated counter-clockwise while leaving the control cam 40 and maximum value indicating wheel 38 as they are. As the diver moves from the state of Fig. 5 to a depth larger than the maximum depth presently indicated by the rotary guide pin 64, the measured value indicating wheel is initiated to rotate clockwise to engage the rotary guide pin 64 of the control cam 40 into the groove portion 50 of the measured value indicating wheel 36. Thus, the mesh portion 70 of the control cam 40 is disengaged from the mesh portion 74 of the keep plate 42. As a result, the control cam 40 and maximum value indicating wheel 38 are rotated to the depth. As the diver begins to surface from the depth, the control cam 40 is engaged by the keep plate 42 at that position to position the control cam 40 and maximum value indicating wheel 38. Thus, only the measured value indicating wheel 36 is initiated to rotate counter-clockwise while indicating the maximum measured value. As the diver completely surfaces from the state of Fig. 5, the measured value indicating wheel 36 is counter-clockwise rotated to zero which means the state of Fig. 6 while leaving the control cam 40 and maximum value indicating wheel 38 at the maximum value indicating position. Therefore, only a single motor is required to rotate the measured value indicating wheel 36 and maximum value indicating wheel 38 and also to position the maximum value indicating wheel 38 at a position of the maximum value. The least number of motors should can be used to suppress the manufacturing cost. The maximum value indicating wheel 38 can be positively positioned by engaging the control cam 40 and keep plate 42 which are rotatably driven as a unit through rotation of the maximum value indicating wheel 38. Any deviation due to vibration, falling or the like can be reliably prevented. Fig. 11 is a plan view showing another embodiment of a depth pointer indicator constructed in accordance with the present invention. A rotary guide pin 80 includes a notch 81 formed therein at one side. Each of the groove portions 50 includes a jam preventing portion 82 formed therein at the inner side and brought into contact with the notch 81. When the maximum value indicating wheel 38 is to be positioned by engaging between the control cam 40 and keep plate 42, the tips of the teeth may jam each other. This can be avoided as follows. When the rotation of the measured value indicating wheel 36 begins to be reversed, the jam preventing portion 82 contacts into the notch 81 in the rotary guide pin 80 to release the jam. The other structure and its function will not be further described since they are similar to those of the previous embodiment. The measuring system and indication method of an analog display measuring instrument according to the present invention will be described in detail. Fig. 13 is a block diagram of one embodiment of an analog display measuring instrument with memory constructed in accordance with the present invention. A pressure sensor 101 is connected to depth calculation means 103 through an A/D converter 102. The depth calculation means 103 computes a depth measurement corresponding to the output of the A/D converter 102. The maximum depth measurement is stored in maximum depth storage means 112 at all times. A first motor 105 functioning as a drive source is controlled by motor control means 121 for causing a depth pointer 107 to indicate the current depth measurement through a first gear train 106 and for causing a maximum depth pointer 108 to indicate the maximum depth. Computation means 104 computes an average depth from the depth computed by the depth calculation means 103 and the time measured by timer means 110. The average depth is then stored in computation result storage means 113 and coupled with the motor control means 121. The time means 110 measures a diving time period which is in turn stored in time information storage means 111 at all times. A second motor 114 functioning as a second drive source is controlled by the motor control means 121 for causing a time information pointer 116 to indicate the diving time through a second gear train 115. Time measurement means 119 senses a measurement initiation time at which the measurement of depth is initiated and which is in turn stored in measurement initiation time storage means 120. A third motor 122 functioning as a third drive source is controlled by the motor control means 121 for causing a time pointer 124 to indicate the measurement initiation time through a third gear train 123. Motor operation discrimination/control means 109 discriminates whether or not the motor is in operation and whether or not the measurement of depth should be carried out and controls the A/D converter 102. Input control means 118 determines whether or not the measurement of depth should be carried out depending on the state of a crown 117 and controls the A/D converter 102. Fig. 12 is a hardware diagram showing one embodiment of the analog display measuring instrument with memory shown in Fig. 13. A microcomputer 901 comprises an A/D converting circuit 903, a RAM 904, a CORE CPU 905, a ROM 906, a timer 913 for controlling one Hz interruption, a motor control circuit 907 for controlling drive states of motor pulses or the others, a sound generator 908 for generating alarm sounds and an input control circuit 912 for controlling a motor driver 909 and external signals, all of which are connected together through buses. The microcomputer 901 is also connected to a sensor 902, a pointer 910, a loudspeaker 911 and input means which is formed by a push switch A (PSW-A) 914, a push switch B (PSW-B) 915, a push switch C (PSW-C) 916, a zero-stage crown switch (RM0) 917, a first-stage crown switch (RM1) 918 and a second-stage crown switch (RM2) 919. The sensor 902 is connected to the A/D conversion circuit 903. The pointer 910 is connected to the motor driver 909. The loudspeaker 911 is connected to the sound generator 908. The push switch A (PSW-A) 914, push switch B (PSW-B) 915, push switch C (PSW-C) 916, zero-stage crown switch (RM0) 917, first-stage crown switch (RM1) 918 and second-stage crown switch (RM2) 919 are connected to the input control circuit 912 such that the normal and other indication modes can be selected. Fig. 17 is a flowchart illustrating Fig. 13. After one Hz interruption, it is determined whether or not the crown is zero-stage (step 501). If not so, the measurement of depth is suspended (step 502). The program terminates. If the crown is zero-stage, it is determined whether or not the first to third motors are in operation (step 503). If the motors are in operation, the measurement of depth is not carried out. The program jumps to step 510. If the motors are not in operation, the measurement of depth is then carried out (step 504) while it is determined whether or not the third motor is stopped (step 505). If the third motor is stopped, the program directly proceeds to the next step. If the third motor is not stopped, the third motor is then stopped (step 506) and the program proceeds to the next step. At step 507, the currently measured depth is compared with the previous measured depth. If the current depth is not larger than the previous depth, then pulses are applied to the first motor (step 509), otherwise, the step 509 is done after the current depth is stored in the maximum depth storage means as a maximum depth (step 508). At step 510, the time required to measure the depth is counted, the counted time being then stored (step 511). Pulses are then applied to the motor 2 (step 512). At step 513, an average depth is computed from the measured depth and time. The average depth is then stored in the computation result storage means (step 514). The program terminates. Fig. 14 is a block diagram of one embodiment of an analog display measuring instrument according to the present invention, including a memory, a memory recall and a confirmation sound generator for generating a confirmation sound on memory recall. A switch 201 is connected to external-inputs-exceeding-a-preset-number detection means 203 through input control means 202. The detection means 203 counts the number of inputs from the switch 201 and causes confirmation sound generating means 206 to generate a confirmation sound corresponding to the counted value through confirmation sound control means 205. At the same time, stored value selection means 204 selects a stored value corresponding to the counted value and calls stored values from maximum depth storage means 207, computation result storage means 208, time information storage means 209 and measurement initiation time storage means 210. The first to third motors are controlled by motor control means 211. The first motor 212 causes a depth pointer 214 to indicate the measured depth through a first gear train 213 and also causes a maximum depth pointer 215 to indicate the maximum depth. The second motor 216 causes a time information pointer 218 to indicate the diving time through a second gear train 217. The third motor 219 causes a time pointer 221 to indicate the measurement initiation time through a third gear train 220. When the detection means 203 senses that the number of inputs from the switch 201 exceeds a preset number, distant computing means 222 computes distances from the respective current positions of the measured depth and time information pointers 214, 218 to 12 o'clock position and a distance from the current position of the time pointer 221 to the present time indicating position. Thus, the motor control means 211 actuates the first to third motors only by the computed distances. If the system of Fig. 14 is accomplished by a CPU system, it becomes similar to that of Fig. 12. Merely by changing the software, there can be accomplished an analog measuring instrument of the present invention, including a memory, a memory recall and a device for generating a confirmation sound on memory recalling. Fig. 14 will be further described with reference to a flowchart shown in Fig. 18. After key interruption, it is determined whether or not the input is from PSW-B (step 601). If the input is not from PSW-B, the program terminates. If the input is from PSW-B, the number of inputs n is counted (step 602). If it is now assumed that the number of memories for diving information is equal to two, it is determined at step 603 whether or not n=3. If n=3, a first confirmation sound is generated (step 615). At the same time, the depth pointer is solely moved clockwise to 12 o'clock position (step 617); the time information pointer is solely moved clockwise to 12 o'clock position (step 618); and the time pointer is solely moved clockwise to the present time indicating position (step 619). The program then terminates. If not n=3, it is then determined whether or not n=2 (step 604). If n=2, a second confirmation sound is generated (step 616). If not n=2, a third confirmation sound is generated (step 605). At step 606, the maximum depth is called from the n-th storage means to apply clockwise pulses to the first motor (step 607). After the first motor has been actuated (step 608), an average depth is called (step 609) to apply counter-clockwise pulses to the first motor (step 610). The diving time is then called (step 611) to apply clockwise pulses to the second motor (step 612). The diving initiation time is then called (step 613) to apply clockwise pulses to the third motor (step 614). The program then terminates. Fig. 15 is a block diagram of one embodiment of an analog display measuring instrument according to the present invention, including means for initializing the stored value. As a command from a switch 301 is received by initializing means 303 through input control means 302, the respective values stored in maximum depth storage means 304, computation result storage means 305, time information storage means 306 and measurement initiation time storage means 307 are erased. Any data is then installed into the respective storage means 304, 305, 306 and 307. If Fig. 15 is realized by a CPU system, it becomes similar to the system of Fig. 12. Merely by changing the software, there can be realized an analog measuring instrument of the present invention including means for initializing the stored value. Fig. 15 will be described with reference to a flowchart of Fig. 19. After one Hz interruption, it is determined whether or not the inputs are from PSW-A+B (or whether or not the inputs are simultaneously from the push switches A and B) (step 701). If the inputs are not from PSW-A+B, the program terminates. If the inputs are from PSW-A+B, any value (dummy data) is written into the maximum depth storage means (step 702); any value (dummy data) is written into the computation result storage means (step 703); any value (dummy data) is written into the time information storage means (step 704); and any value (dummy data) is written into the measurement initiation time storage means (step 705). The program terminates. Fig. 16 is a block diagram of one embodiment of an analog display measuring instrument according to the present invention, including means for setting the home position of the maximum and current depth pointers. A switch 401 is connected to home position setting means 403 through input control means 402. Motor control means 404 is actuated by a command from the home position setting means 403 to control a first motor 405. A depth pointer 407 and a maximum depth pointer 408 are driven by the first motor 405 through a gear train 406 to be returned to the home position of the depth pointer 407 and the maximum depth pointer 408. If Fig. 16 is realized by a CPU system, it becomes similar to that of Fig. 12. Merely by changing the software, there can be accomplished an analog display measuring instrument of the present invention including means for setting the home position of the maximum and current depth pointers. Fig. 16 will be described with reference to a flowchart of Fig. 20. After key interruption, it is determined whether or not a crown RM is zero-stage (step 801). If it is zero-stage, the program terminates. If the crown RM is not zero-stage, it is then determined whether or not the maximum depth pointer is in 12 o'clock position (step 802). If it is in 12 o'clock position, the program terminates. If the maximum depth pointer is not in 12 o'clock position, the depth pointer is solely moved clockwise to 12 o'clock position (step 803). The program then terminates. The present invention is not limited to the aforementioned embodiments, but various modifications can be made within the scope of the invention. For example, the pointer unit of this invention may be similarly used in any one of barometer, thermometer, altimeter and other meters in addition to the depth meter as described. The present invention may be similarly applied to a form of indicating the current and minimum values other than the maximum value. The motor functioning as a drive source may be replaced by another drive source such as flat spiral spring or the like. The cam bias means is not limited to the leaf spring, but may be replaced by any other suitable bias means such as helical spring or the like. The projections 62 may be formed in the control cam, rather than in the maximum value indicating wheel. Although the mesh portion of the keep plate has been described as having 60 teeth thinned out for every one pitch, the teeth in the mesh portion may be thinned out for every two pitches with similar advantages. The present invention provides an analog display measuring instrument comprising: a measured value pointer for indicating a current value measured by a measuring means; a maximum or minimum value pointer movable only in an incremental or decremental direction and interlocked with the measured value pointer; a gear train for driving the measured value pointer; a drive source for driving the gear train; and a control means for controlling the drive source to move the measured value pointer to a position corresponding to a measured value obtained by the measuring means. The present invention also provides a pointer unit in an analog display measuring instrument comprising a measured value pointer for indicating a current measured value and a maximum or minimum value pointer to be placed at the maximum or minimum measurement position for indicating the maximum or minimum value, the measured value pointer being rotatably connected to one drive source, wherein the maximum or minimum value pointer rotates with rotation of the measured value pointer and stops at a position of the maximum or minimum value during measurement. This invention also provides a method for indicating measurements with an analog display which performs measuring by a measuring means, moves a measured value pointer by a drive source through a gear train to indicate a value measured by the measuring means, and moves a maximum or minimum value pointer to indicate the maximum or minimum value measured by the measuring means, comprises the steps of: controlling the drive source through a control means to move the measured value pointer to a position corresponding to a value measured by the measuring means; and interlocking the maximum or minimum value pointer with the measured value pointer such that the maximum or minimum value pointer is moved only in an incremental or decremental direction. The aforegoing description has been given by way of example only and it will be appreciated by a person skilled in the art that modifications can be made without departing from the scope of the present invention.

Claims: A pointer unit for use in an analog display measuring instrument comprising a measured value pointer (28) for indicating a current measured value and a maximum or minimum value pointer (30) to be placed at the maximum or minimum measurement position for indicating the maximum or minimum value, said measured value pointer being connected to a drive source (105), characterised in that said maximum or minimum value pointer is interlocked with said measured value pointer and further comprising a control cam (40) for stopping said maximum or minimum value pointer at a position of the maximum or minimum value during measurement. A pointer unit for use in an analog display measuring instrument as defined in claim 1, further comprising: a measured value indicating wheel (36) rotatably connected to said drive source for rotating said measured value pointer; a maximum or minimum value indicating wheel (38) for rotating said maximum or minimum value pointer; said control cam stopping said maximum or minimum value indicating wheel at the maximum or minimum measurement position according to rotation of said measured value indicating wheel to stop said maximum or minimum value pointer; and a keep plate (42) engageable with said control cam for stopping said control cam; wherein said measured value indicating wheel includes means (48, 50, 52) for driving and stopping said control cam; said maximum or minimum value indicating wheel includes a cam engagement (54, 58) which engages with said control cam in a rotational direction of said maximum or minimum value indicating wheel and enables said control cam to slide in a diametric direction of said maximum or minimum value indicating wheel, and cam bias means (56) for biasing said control cam in said diametric direction; said control cam includes a mesh portion (70) engageable with said keep plate to stop said maximum or minimum value indicating wheel; and said keep plate includes another mesh portion (74) formed therein at a position opposite to said mesh portion of said control cam and engageable with the mesh portion of said control cam. A pointer unit as defined in claim 2; wherein said measured value indicating wheel comprises an annular rotation slit (48) having non-connected ends and functioning as a driving and stopping means for said control cam and a groove portion (50) formed therein at least one end for releasing said control cam from stoppage; and wherein said control cam includes a rotary guide pin (64) which is fitted in said rotation slit to engage with said measured value indicating wheel in a given direction, engagement means (66) which rotatably engages with said cam engagement and slides in the diametric direction of said maximum or minimum value indicating wheel and a contact portion (68) brought into contact with said cam bias means to receive biasing force; said mesh portion of said control cam being formed on the outer periphery of said control cam at a position opposite to said contact portion. A pointer unit as defined in claim 3 wherein said groove portion formed in said rotation slit for releasing said control cam from stoppage has a sloped bias portion (52) for biasing said rotary guide pin of said control cam in the outward direction. The pointer unit as defined in any one of claims 2 to 4 wherein one of opposed surfaces of said maximum or minimum value indicating wheel and control cam includes a plurality of projections (62) formed thereon for preventing close contact of said maximum or minimum value indicating wheel with said control cam. The pointer unit as defined in any one of claims 2 to 5 wherein said mesh portion of the keep plate includes a plurality of teeth (76) formed therein and equidistantly spaced away from one another and wherein said mesh portion of the control cam also includes teeth each of which outwardly or inwardly engages with any adjacent two teeth (72) in the mesh portion of the keep plate. A pointer unit as defined in claim 3 wherein said groove portion formed in said rotation slit of said measured value indicating wheel for releasing said control cam from stoppage includes jam preventing means (82) for preventing a jam produced when said control cam engages with the keep plate. An analog display measuring instrument comprising: a pointer unit as claimed in any preceding claim and further comprising; a gear train (106) for driving said measured value pointer; said drive source driving said gear train; and a control means (121) for controlling said drive source to move said measured value pointer to a position corresponding to a measured value obtained by a measuring means (37). An analog display measuring instrument as defined in claim 8, further comprising: an input means (118) being able to select a first or second indication mode; a maximum or minimum value storage means (112) for storing the maximum or minimum value among values measured by said measuring means; a computation means (104) for performing a specific computation relative to a value measured by said measuring means; and a computation result storage means (113) for storing a computed result; wherein said control means controls said drive source to move said measured value pointer to a position corresponding to a value measured by said measuring means when the first indication mode is selected by said input means, or to a position corresponding to the maximum or minimum value stored in said maximum or minimum value storage means and then to a position corresponding to a computed result stored in said computation result storage means when the second indication mode is selected by said input means, whereby values respectively stored in said maximum or minimum value storage means and computation result storage means can be simultaneously indicated. An analog display measuring instrument as defined in claim 9, further comprising an initializing means (303) for writing specific values into said maximum or minimum value storage means and said computation result storage means. An analog display measuring instrument as defined in claim 9 or claim 10 wherein said computation means computes an average value of measurements. An analog display measuring instrument as defined in any one of claims 8 to 11, further comprising: a timer means (110) for measuring an elapsed time; a time information pointer (116) for indicating time information obtained by said timer means; a second gear train (115) for driving said time period information pointer; and a second drive source (114) for driving said second gear train; wherein said control means controls said second drive source to move said time information pointer to a position corresponding to a time measured by said timer means, whereby a measured value by said measuring means can be simultaneously indicated with time information from said timer means. An analog display measuring instrument as defined in any one of claims 9 to 11, further comprising: a timer means (110) for measuring an elapsed time; a time information pointer (116) for indicating time information obtained by said timer means; a second gear train (115) for driving said time information pointer; a second drive source (114) for driving said second gear train: and a time information storage means (111) for storing time information obtained by said timer means; wherein said control means controls said second drive source to move said time information pointer to a position corresponding to a value stored in said time information storage means when the second indication mode is selected by said input means, whereby the maximum or minimum value stored in said maximum or minimum value storage means, a value stored in said computation result storage means, and time information stored in said time information storage means can be simultaneously indicated. An analog display measuring instrument as defined in claim 13, further comprising an initializing means (303) for writing specific values into said time information storage means. An analog display measuring instrument as defined in any one of claims 8 to 14, further comprising: a time measuring means (119) for measuring a present time; a time pointer (124) for indicating a present time measured by said time measuring means; a third gear train (123) for driving said time pointer; and a third drive source (122) for driving said third gear train: wherein said control means controls said third drive source such that a present time measured by said time measuring means is indicated by said time pointer when said measuring means is not in operation, and a time at which said measuring means has started measuring is indicated when said measuring means is in operation. An analog display measuring instrument as defined in any one of claims 9 to 14, further comprising: a time measuring means (119) for measuring a present time; a time pointer (124) for indicating a present time measured by said time measuring means; a third gear train (123) for driving said time pointer; a third drive source (122) for driving said third gear train; and a measurement initiation time storage means (120) for storing a time of measurement initiation of said measuring means; wherein said control means controls said third drive source to move said time pointer to a position corresponding to a time stored in said measurement initiation time storage means when the second indication mode is selected by said input means, whereby the maximum or minimum value stored in said maximum or minimum value storage means, a value stored in said computation result storage means, and a time stored in said measurement initiation time storage means can be simultaneously indicated. An analog display measuring instrument as defined in claim 16, further comprising an initializing means (303) for writing specific values into said measurement initiation time storage means. An analog display measuring instrument as defined in any one of claims 9 to 17, further comprising a home position setting means (403) for returning said measured value and maximum or minimum value pointers to a home position, wherein said control means controls said home position setting means to operate said drive source to move said measured value and maximum or minimum value pointers to said home position. An analog display measuring instrument as defined in any one of claims 9 to 18; wherein said input means selects one of various types of second indication modes to indicate data stored in said maximum or minimum value storage means or said computation result storage means; and wherein said maximum or minimum value storage means or said computation result storage means is selected by selecting one of the second indication modes by said input means to move said measured value pointer to a position corresponding to a measured value stored in a selected storage means; said analog display measuring instrument further comprising confirmation sound generating means (206) for generating a confirmation sound when one of the second indication modes is selected by said input means and a confirmation sound control means (205) for causing said confirmation sound generating means to generate a type of sound corresponding to the second indication mode selected by said input means. An analog display measuring instrument as defined in any one of claims 9 to 19; wherein said input means selects one of the second indication modes for said maximum or minimum value or computation result storage means depending on the number of inputs; wherein said control means controls said drive source depending on the number of inputs from said input means to move said measured value pointer to a position corresponding to a measured value stored in selected storage means; and wherein said control means controls said drive source to move said measured value pointer to a position of the measured value when the number of inputs from said input means exceeds a set number. An analog display measuring instrument as defined in any one of claims 8 to 20, further comprising an operation discriminating and controlling means for suspending an operation of said measuring means until said measured value pointer shows a result of a preceding measurement. An analog display measuring instrument as defined in any one of claims 8 to 21, further comprising a crown input means interlocked with a crown and an input control means for stopping an operation of said measuring means when there is an input from said crown input means. An analog display measuring instrument as defined in claim 22 wherein said crown is of a screw lock type. An analog display measuring instrument as defined in any one of claims 8 to 23 wherein said measuring means measures any one of depth of a diver, atmospheric pressure, temperature and altitude. A method for indicating measurements with an analog display which performs measuring by a measuring means (37), moves a measured value pointer (28) by a drive source (105) through a gear train (106) to indicate a value measured by said measuring means, and moves a maximum or minimum value pointer (30) to indicate the maximum or minimum value measured by said measuring means, comprising the steps of: controlling said drive source through a control means (121) to move said measured value pointer to a position corresponding to a value measured by said measuring means; and characterised by interlocking said maximum or minimum value pointer with said measured value pointer such that said maximum or minimum value pointer is moved only in an incremental or decremental direction; and operating a control cam (40) for stopping said maximum or minimum value pointer. A method for indicating measurements with an analog display as defined in claim 25, further comprising the steps of: storing the maximum or minimum value among values measured by said measuring means in a maximum or minimum value storage means (112), performing a specific computation relative to a value measured by said measuring means using a computation means (104); and storing a computation result in a computation result storage means (113); wherein said control means controls said drive source to move said measured value pointer to a position corresponding to a value measured by said measuring means when a first indication mode is selected by an input means (118) which can select a first or second indication mode, or to a position corresponding to the maximum or minimum value stored in said maximum or minimum value storage means and then to a position corresponding to a computed result stored in said computation result storage means when the second indication mode is selected by said input means, whereby values respectively stored in said maximum or minimum value storage means and computation result storage means can be simultaneously indicated. A method for indicating measurements with an analog display as defined in claim 25 or claim 26, further comprising the steps of: measuring an elapsed time by a timer means (110); and controlling a second drive source (114) by said control means to move a time information pointer (116) to a position corresponding to an elapsed time measured by said timer means through a second gear train (115), whereby a value measured by said measuring means can be simultaneously indicated with time information from said timer means. A method for indicating measurements with an analog display as defined in any one of claims 25 to 27, further comprising a step of controlling a third drive source (122) by said control means for driving a time pointer (124) through a third gear train (123) such that a present time measured by a time measuring means (119) is indicated when said measuring means is not in operation, and a time at which said measuring means has started measuring is indicated when said measuring means is in operation. A method for indicating measurements with an analog display as defined in any one of claims 25 to 28, further comprising the steps of: detecting a current position of said measured value pointer by a home position setting means (403); and controlling said home position setting means to move said measured value and maximum or minimum value pointers to the home position by said control means. A method for indicating measurements with an analog display as defined in any one of claims 25 to 29, further comprising the steps of: discriminating whether or not said drive source is in operation by a discriminating and controlling means (109) after measurement is initiated; and suspending an operation of said measuring means until said measured value pointer shows a result of a preceding measurement when said drive source is in operation. A method for indicating measurements with an analog display as defined in any one of claims 25 to 30, further comprising a step of stopping an operation of said measuring means by an input control means when said input control means receives an input from a crown input means interlocked with a crown.

Inventors: KAWAGUCHI TAKASHI, KUBOTA MASARU, NAKAMURA HIDENORI, OGUCHI KEIICHIRO, KAWAGUCHI, TAKASHI, KUBOTA, MASARU, NAKAMURA, HIDENORI, OGUCHI, KEIICHIRO
Applicants: SEIKO EPSON CORP, SEIKO EPSON CORPORATION
Application year: 1995
Main classification: G01D13
IPC codes: G01D1, G04C3, B63C11, G01C13, G01D13, G04B47, G04G99