Abstract:
A time switch mechanism for automatically as well as manually operating a switch incorporated therein for the purpose of controlling the operation of a device such as a television or a radio, as well as a sleep timer. The time switch mechanism comprises a timing cam, a time setting member, a normally closed microswitch for operating the television or radio, a switch lever for operating the microswitch and cooperable with the timing cam and a switching cam, wherein the switching cam is operably secured to a sector gear which is rotatable at a predetermined speed.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a time switch mechanism and, more particularly to a time switch mechanism adapted to be incorporated in a television, a radio and the like and capable of automatically as well as manually operating a switch for playing music or generating an alarm. 
     In general, a time switch of the type described above is so operated that the electrical power switch is automatically closed by a clock mechanism at a predetermined set time and, after the lapse of a set time period, the electric power switch is opened and the electrical power switch is again closed and opened at the set times, respectively, in the next day, and the above sequence is repeated daily. It is also desired that the time switch is closed and opened manually at desired times, respectively. Further, the time switch is used as a so-called sleep timer in which the switch is closed for a desired time period before the sleeping time and then opened until the set time is reached for closing the switch. 
     The above described types of the time switch have been proposed and widely used. However, in the prior art time switches, all of them are provided with a plurality of switches, each exclusively adapted to be operated automatically by a clock mechanism, or to be operated manually or to be operated as a sleep timer, thereby resulting in complicated mechanical as well as electrical construction and high cost of the time switch mechanism while the operation is made complicated. 
     The present invention aims at avoiding the above described disadvantages of the prior art time switch mechanisms. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a novel and useful time switch mechanism which is simple in construction and inexpensive and easy to operate and in which only a single switching member and a single switch are provided in order to permit the above described automatic control by a clock mechanism and manual control as well as control, for the sleep timer, to be carried out. 
     The above object is achieved in accordance with the present invention by providing a time switch mechanism having a switch to be opened and closed thereby, the switch mechanism being characterzied by a switch lever urged to be rotated from a first terminal position through an intermediate position to a second terminal position and operably coupled with the switch for operating the same to its one position when the switch lever is positioned at the first and the second terminal position while the switch is switched to its other position when the switch lever is positioned at the intermediate position, a switching cam operably coupled with the switch lever, an adjustable time setting member for adjustably setting an operating time, and an axially movable timing cam rotated at a predetermined speed and coupled with the time setting member so that the timing cam is moved axially to a first position when the operating time set by the time setting member is reached while the timing cam is held at a second position before the operating time is reached as well as after the lapse of a predetermined time after the operating time is reached, and the timing cam being operably coupled with said switch lever. 
     In accordance with an embodiment of the present invention, a gear frictionally rotated at a predetermined speed is provided and a sector gear is secured integrally with the switching cam, the sector gear being so positioned that it meshes with the gear when a portion of the switching cam is engaged with the switch lever to position the switch at its one position, thereby permitting the switching cam to be switched to its first position by the gear engaging with the sector gear allowing the switch lever to move between its intermediate position and its second terminal position, thus rendering the switch mechanism to be used as a sleep timer. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic view partly in section showing a first embodiment of the switch mechanism of the present invention; 
     FIG. 2 is a schematic view similar to FIG. 1 but showing a second embodiment of the present invention; 
     FIG. 3 is a schematic view of the embodiment shown in FIG. 1, illustrating the position of the parts thereof when a preselected time period has elapsed and the switch has been actuated, for example, to turn off a television or radio; 
     FIG. 4 is a schematic view of the embodiment illustrated in FIGS. 1 and 3, showing the parts thereof in the position wherein the switch of a television or radio has again been turned on after a predetermined period of sleeping time; 
     FIG. 5 is a schematic view of the first embodiment of the invention, as illustrated in FIGS. 1, 3 and 4, but showing a manually set condition of the switch for turning off, for example, a television or radio; and 
     FIG. 6 is a schematic view of the first embodiment of the present invention, as illustrated in FIGS. 1, 3, 4 and 5, showing the manually set condition of the parts thereof for maintaining the television or radio in an operative state. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, a disc-like timing cam 1 having a projection 1a formed at its one side surface is rotated in the direction indicated by the arrow at a predetermined speed, for example, one revolution per 24 hours, by a clock mechanism (not shown) and is supported axially shiftably and urged toward the left by a spring 2. A disc-like time setting member 3 having a recess 3a formed therein is coaxially supported with respect to the timing cam 1 adjacent thereto so that the timing cam 1 is urged against the time setting member 3 by the spring 2. The angular position of the time setting member 3 is adjustable so that the operating time is set by the angular position of the time setting member 3. The projection 1a of the timing cam 1 is provided with an inclined leading edge and normally abuts against the side surface of the time setting member 3 so as to keep the timing cam 1 spaced a small distance from the time setting member 3, but, when the projection 1a of the timing cam 1 fits in the recess 3a of the time setting member 3 as the timing cam 1 rotates, the timing cam 1 is moved axially toward the time setting member 3 to abut against the same, and after the lapse of a predetermined time period determined by the length of the recess 3a, the projection 1a is disengaged from the recess 3a so that the timing cam 1 is again moved apart from the time setting member 3 to assume the original position. 
     A switch lever 5 having radially extending arms 5a, 5b and 5c is rotatably supported by a shaft 6, and urged by a spring 7 in the clockwise direction. The bent lug of the arm 5c is positioned adjacent to the timing cam 1 as shown, while the arm 5b is positioned adjacent to the actuator 4a of a microswitch 4 so that the switch 4 is actuated by the arm 5b when the switch lever 5 is rotated in the clockwise direction to move the arm 5b across the actuator 4a. 
     A switching cam 8 having cam portions 8a, 8b and 8c each adapted to cooperate with the arm 5a of the switch lever 5 is rotatably supported by a shaft 9 and urged by a spring 10 in the counterclockwise direction. The configuration of the cam portions 8a, 8b, 8c is so determined that the arm 5b is arrested as a position apart from the actuator 4a of the switch 4 during counterclockwise direction of rotation of the switch lever 5 from the position shown in FIG. 1, when the cam portion 8a contacts the arm 5a. On the other hand, the arm 5b is made movable in the clockwise direction between a position at which the arm 5b contacts and actuates the actuator 4a of the switch 4 and a position apart from the actuator 4a when the cam portion 8b of the switching cam 8 is faced against the arm 5a, as shown in FIGS. 3 and 4, and, when the cam portion 8c abuts against the arm 5a, the arm 5b is arrested at the position at which the arm 5b actuates the actuator 4a of the switch 4, as shown in FIG. 5. 
     The configuration of the arm 5c of the switch lever 5 is so determined that, when the cam portion 8a is engaged with the arm 5a, the arm 5c is held apart from the timing cam 1 when the same is held apart from the time setting member 3 by the projection 1a so that the switch lever 5 is absolutely isolated from the actuation of the timing cam 1, as shown in FIGS. 1 and 6. When the cam portion 8b is faced against the arm 5a, as shown in FIG. 3, the arm 5c abuts against the timing cam 1 when the same is held apart from the time setting member 3 by the projection 1a, so that the arm 5b actuates the actuator 4a of the switch 4 with a certain clearance held between the cam portion 8b and the arm 5a. However, when the timing cam 1 is moved toward the time setting member 3 by the engagement of the projection 1a with the recess 3a at the set operating time as the timing cam 1 rotates, the arm 5c is allowed to follow the movement of the timing cam 1 by virtue of the clearance held between the cam portion 8b and the arm 5a so that the arm 5b moves in the clockwise direction of rotation of the lever 5 and is disengaged from the actuator 4a so as to deactuate the switch 4. When the cam portion 8c is faced against the arm 5a, the cam portion 8c abuts against the arm 5a or the same is moved closely adjacent to the arm 5a while the arm 5c abuts against the timing cam 1 held apart from the time setting member 3 by the projection 1a, as shown in FIG. 5, the arm 5b is held at the position at which it continues to actuate the switch 4 regardless of the movement of the timing cam 1 at the operating time. This is because of the fact that the switch lever 5 is arrested at the position at which the arm 5b continues to actuate the switch 4 because the cam portion 8c abuts against the arm 5a even immediately after the movement of the timing cam 1 toward the time setting member 3 at the operating time, thereby preventing the arm 5b from moving apart from the position at which the same actuates the switch 4. 
     A sector gear 8d is integrally secured to the switching cam 8 and the sector gear 8d is adapted to mesh with a gear 11 which is frictionally supported by a shaft 12 rotated at a predetermined speed in the clockwise direction as shown, so that the switching cam 8 is rotated in the counterclockwise direction during the time the sector gear 8d meshes with the gear 11. 
     The sector gear 8d is provided with a pin 8e secured thereto and the rotation of the sector gear 8d and, hence, the switching cam 8 is limited by a stopper 13 as shown. A leaf spring 14 having bent portions 14a, 14b is secured to the stopper 13. The spring 14 serves to temporarily hold the switching cam 8 at the position at which he cam portion 8b is faced against the arm 5a of the switch lever 5 by the abutment of the pin 8e against the bent portion 14a of the spring 14 when the switching cam 8 is rotated in the counterclockwise direction by the spring 10 after the disengagement of the sector gear 8d from the gear 11, as shown in FIGS. 3 and 4, while the switching cam 8 is temporarily held at the position at which the cam portion 8c abuts against the arm 5a, as shown in FIG. 5, when the pin 8e engages with the bent portion 14b of the spring 14, as the switching cam 8 is manually rotated in the counterclockwise direction so as to bring the pin 8e into the bent portion 14b. 
     When the switching cam 8 is further rotated manually in the counterclockwise direction and stopped by the stopper 13 engaged with the pin 8e, the cam portion 8a comes again into contact with the arm 5a so that the arm 5c is held apart from the timing cam 1 so as to be isolated from the actuation of the timing cam 1. 
     In operation, starting from the state shown in FIG. 1 and assuming that the switch 4 used in FIG. 1 is a normally closed switch, the sector gear 8d meshes with the gear 11 and the switch lever 5 is so positioned that the arm 5a contacts with the cam portion 8a of the switching cam 8. Thus the arm 5b is held apart from the switch 4 thereby maintaining the switch 4 in the closed position and the arm 5c is held apart from the timing cam 1. Therefore, when the sector gear 8d is rotated in the counterclockwise direction by the gear 11 and disengaged therefrom as the gear 11 rotates, the switching cam 8 is rotated in the same direction by the action of the spring 10 and the pin 8e is arrested by the bent portion 14a of the spring 14, as shown in FIG. 3, so that the switching cam 8 is held at the position at which the cam portion 8b is faced against the arm 5a  of the switch lever 5. Thus, the switch lever 5 is allowed to rotate in the clockwise direction by the action of the spring 7, and, when the timing cam 1 is held apart from the time setting member 3 by the projection 1a, then the arm 5c abuts against the timing cam 1 and held in the position with a clearance being held between the arm 5a and the cam portion 8b, so that the arm 5b is held at the position at which it continues to actuate or open the switch 4. Therefore, by appropriately setting the initial position of engagement of the sector gear 8d with the gear 11, the switch mechanism of the present invention serves as the sleep timer by which the play of the television or the radio incorporating the switch mechanism therein is continued for a certain time period until the time for sleeping arrives, and, thereafter, the play is automatically stopped. After the switch 4 is opened, the timing cam 1 continues to rotate and, when the projection 1a is fitted in the recess 3a  of the time setting member 3 at the operating time set thereby, the timing cam 1 is moved toward the time setting member 3 by the action of the spring 2 so that the arm 5c is allowed to follow the movement of the timing cam 1 by virtue of the clearance having been held between the cam portion 8b and the arm 5a switch lever 5, thereby permitting the arm 5b to move apart from the switch 4 by the rotation of the switch lever 5 in the clockwise direction until the arm 5a abuts against the cam portion 8b so as to close the switch 4, as shown in FIG. 4. In this case, the clockwise rotation of the switch lever 5 may be arrested by the timing cam 1 abutting against the arm 5c instead of the abutment of the arm 5a against the cam portion 8b. If the switching cam 8 is held in this position, the projection 1a is disengaged from the recess 3a after the lapse of the predetermined time period by the rotation of the timing cam 1 so that the timing cam 1 is moved apart from the time setting member 3 thereby urging the arm 5c in the counterclockwise direction so as to move the arm 5b to the position at which the arm 5b actuates the actuator 4a or opens the switch 4. Thereafter, the switch 4 is automatically closed and opened at the set operating time each time the timing cam 1 rotates one revolution. This operation is the automatic control by the switch mechanism. 
     When the switching cam 8 is manually rotated in the counterclockwise direction from the position shown in FIG. 1 to the position at which the cam portion 8c is faced against the arm 5a and set in this position, as shown in FIG. 5, the sector gear 8d is disengaged from the gear 11 after the same has been frictionally slid relative to the shaft 12 during the meshing of the gear 11 with the sector gear 8d and the switching cam 8 is held in this position by the engagement of the pin 8e with the bent portion 14b of the spring 14 despite the action of the spring 10. In this position, the arm 5b continues to actuate or open the switch 4 because the arm 5c is not influenced by the actuation of the timing cam 1 by virtue of the engagement of the cam portion 8c with the arm 5a and the gear 11 is held disengaged from the sector gear 8d. This operation is the manual operation for holding the switch 4 in the opened position. 
     When the switching cam 8 is further rotated manually in the counterclockwise direction until the pin 8e is arrested by the stopper 13, as shown in FIG. 6, so that the arm 5a engages with the cam portion 8a, the switch lever 5 is rotated in the direction against the action of the spring 7 so that the arm 5b is disengaged from the actuator 4a of the switch 4 and held in this position thereby maintaining the switch 4 in the closed position, because in this position, the sector gear 8d is held disengaged from the gear 11 and the arm 5c is held apart from the timing cam 1. This operation is the manual operation for closing the switch 4. 
     The spring 10 may be dispensed with in order to achieve the proper operation of the switch mechanism. In this case, the terminal position of the sector gear 8d is so set that the cam portion 8b comes to the position at which the same is faced against the arm 5a when the sector gear 8d is disengaged from the gear 11 as the same rotates. With this arrangement, the switch lever 5 is rotated in the clockwise direction during the time the sector gear 8d is still meshing with the gear 11 so that the switch 4 is switched. However, this condition is allowable in achieving the proper function of the switch mechanism. 
     FIG. 2 shows an alternative form of the present invention. This embodiment is substantially similar to that of FIG. 1 except that the configuration of the arm 5&#39;b is made V-shape instead of the rounded shape of the arm 5b of FIG. 1 and the switch 4 is made a normally opened switch. The operation is the same with the embodiment of FIG. 1. 
     As described above, it is apparent that the present invention provides a useful switch mechanism simple in construction and inexpensive to manufacture and capable of functioning accurately as the automatic control and the manual control device of the appliance such as the television and the radio and the like as well as the sleep timer. All the functions are achieved by the provision of a single switch lever 5 cooperating with the switching cam 8 and the switch 4 without requiring a high accuracy of the machining and the complicated electric circuit.