Patent GB-318563-A (GB)
Title: Improvements in and relating to speed indicating and recording apparatus particularly applicable for use with ships' logs
IPC: G01P5/07
Filed: 1928-05-05
Abstract: 318,563. Chernikeeff, B. May 5, 1928. Recording by coordinates.-In apparatus particularly for use with ship's logs of the type described in Specifications 177,187, and 193,254, [both in Class 97 (ii), Surveying &c. instruments], the impulses from the log or other distance measuring device are transmitted to an electromagnet, the armature of which actuates ratchet wheel freely mounted on a spindle to which is secured a second ratchet wheel carrying an indicating pointer or operatively con. nected with a recording pen arm. The ratchet wheels have cooperating projections and each wheel is acted upon by a spring tending to return it to initial position, the movement being prevented during the measuring period by detent pawls pivotally mounted on the armatures of electromagnets. At the end of such period the second ratchet wheel is released to take up a position corresponding to that of the first ratchet wheel, it is then held in adjusted position and the first ratchet wheel released to return to zero position. As shown in Figs. 1 and 2, an electromagnet 13, put into circuit during a period of time governed by a clockwork mechanism, receives impulses from the distance measuring element to operate its armature arm 14 attached to which is a pawl 22 actuating a ratchet wheel 31 loose on a shaft 32 and having a boss 33 connected to one end of a spring enclosed in a box 34. The arm 14 is controlled by an adjustable spring 18 and is surrounded by a sheath-like member 26 to which the magnetic armature 17 is attached, the connection between the sheath 26 and arm 14 being effected by means of a pin 28 on the arm and a coiled spring arranged between the sheath and an abutment 29 on the pin. The ratchet wheel 31 carries an abutment 36 extending into the path of a finger on the shaft 32 or on a second ratchet wheel 38 secured to the shaft, the wheel being connected to a spring in a box 39 in a manner similar to that described above. The ratchet wheel 38 carries an index movable over a scale graduated in speed values. The ratchet wheels are held in position by check pawls 35, 40, provided with armatures 52, 42, associated with electromagnets 51, 41 respectively. At the end of the measuring period the electromagnets are energized, first the magnet 41 is operative to release the pawl 40 and permit the ratchet wheel 38 and index to move, if the speed is decreasing, until the finger 37 engages the abutment 36 whereupon the pawl is re-engaged and subsequently the magnet 51 is energized to release the pawl 35 and permit the ratchet wheel 31 to return to initial position the wheel being arrested in the zero position by a projection 49 thereon engaging a fixed stop 50. If the speed is increasing the abutment 36 drives the finger 37 and advances the index directly. The time element comprises an escapement mechanism 77 and clocktrain 81 - - 86 the last wheel meshing with a pinion 87 on the spindle of a barrel 53 provided with cams 54, 55, 56, Figs. 3 and 5, co-operating with corresponding pairs of contacts 67, 68, 69 in the circuits of the respective electromagnets 13, 51, 41. The upper contact of each pair is connected to a common contact 65 and each of the lower ones is connected to a separate contact strips 58, 59, 60 in an insulating block 57 each being provided with a terminal 61 and an adjusting screw 62 for regulating the distance be tween the platinum points 71, 74 of the pairs of contacts. The spindle 90 of the wheel 86 is acted upon by the main spring which is adapted to be maintained wound up automatically by means of a pawl 99, carried by a spring arm 93 on the armature of an electromagnet 91, engaging a ratchet wheel 102 secured to the main spring box 103. Overwinding is prevented by a depending pin on the ratchet wheel engaging a stop carried by the spindle 90. The switch controlling the circuit of the electromagnet 91 comprises a pair of contacts 104, 105, Figs. 1 and 4, mounted in an insulating block 108 and adapted to co-operate with cam wheels 118, 117 respectively on the spindle of the pinions 84, 85. The cam wheels have the same number of teeth arranged in staggered relation but are of. different diameter and serve to form a quick make and break. The circuit arrangements are shown in Fig. 5 the relay circuit 127, 128, 129 through the closure of contacts 125, 126, by the distance measuring element such as the impeller 124 of a log, closing the circuit contacts 130, 131 for the magnets 13, 41, 51, and 91. The switch of the winding circuit is represented by the contact 122. In the form shown in Figs. 6 and 7 for recording the speed the spindle 32 carries a pinion 132 gearing with a sector 133 and a second sector 136 in gear therewith carries a recording pen arm 137. The pen 'is attached to the arm 137 by means of a spring plate 139 and is constituted by a cylindrical ink container 141 provided with a vent stopper and with a hollow screwed member 143 extending through the arm 137 and through which passes the straightened end of a coiled spring 144 which functions as a needle valve to permit the ink to flow by capillary force when the needle is pressed on the record-strip. The record-strip passes from a: supply roller 146 to a receiving roller 147 over a bridge 148 and a driving roller 148a frictionally engaging the roller 147 or the portion of the strip wound thereon so as to compensate for its varying effective diameter. The spindles of the rollers are mounted in end plates 149, 150 the upper one being arranged in bayonet slots and connected by springs 154 to the lower roller. A train of gears 157 - - 160 and a ratchet wheel 161 is employed to drive the roller 148a. The ratchet wheel is actuated by a pawl 162 on the armature 163 of an electromagnet 164 connected in parallel with one or other of the electromagnets 41, 51. When indications or records are required at several positions the device described functions as a master instrument and indicating or recording repeater instruments are provided at different positions the corresponding electromagnets being connected in parallel. The total distance travelled may be registered by connecting the electromagnet 13 permanently in the circuit so as to transmit the impulses step by step to the shaft 32 to actuate a dial and pointer counting- mechanism, the releasing electromagnets 41, 51, and associated mechanism being rendered unnecessary.. Specification 26685/12, [Class 106 (iii), Fares &c.], also is referred to.