Patent GB-319413-A (GB)
Title: Improvements in apparatus for mechanical coursing
IPC: B61B12/02
Filed: 1928-06-20
Abstract: 319,413. Grozier, T. H., and Hinks, L. H. June 20, 1928. Elevated railways; rope railways. - In dog - racing apparatus having a carriage propelled by an endless cable around a track and a lure arm extending through a side opening in the track housing, mechanism is provided on the carriage for retracting the arm into the housing, distantly - operated electro - mechanical means being situated on the carriage for controlling the mechanism. The carriage consists of side plates 15, Fig. 4, between which are upper grooved wheels 18 running against an upper rail 6 and lower ,grooved wheels 17 running against a lower rail 5. The upper wheels are pressed against the rail by having their axles mounted on levers 23 connected to springs 25. Horizontal steadying wheels 30 are similarly spring pressed against the sides of the lower rail adjacent the lower wheels 17. The endless cable 32 is supported on inclined pulleys 33, Fig. 9, and is driven by a drum 44, Fig. 3, connected to an electric motor through a clutch and variable speed gearing situated beneath a control tower. Two sets of variable speed gear may be provided, the second being used when the first is out of order. The cable passes round two guide pulleys 47, 49, Fig. 3, round the drum, round a contact-making wheel 51, round the drum to a tensioning pulley 53 and round the drum again to the track via guide pulleys 54, 55. The cable is gripped by being wedged in a swivelling jaw attached to the carriage but electrically insulated therefrom, a firm grip being obtained by the cable becoming slightly kinked. The swivelling lure arm 14 is connected by ropes 147, 148 to a crosshead 143 moving on slide bars 144 fixed to the moving carriage. A movement of the crosshead causes the arm to swing either into or out of the track housing, a shock-absorbing device 171 being provided on the carriage. The lure is attached to a swivelling bracket 179 connected to a pulley round which is passed a rope 183 connected at one end to a spring 184 and at the other to the carriage. A swivelling movement of the lure arm 14 causes a partial rotation of the pulley and so keeps the lure in a head-on direction. The movement of the crosshead is effected by a connecting rod 141 from a crank 140 on a clutch shaft 127. The driving cable is, energized by an electric generator situated in the control tower and connected via a button switch on the control tower with brushes and slip rings on the axle of the contact-making wheel 51, the pulleys, drums &c., being suitably insulated and the current being collected by the insulated jaw and conveyed by a cable 102 to a solenoid 103 situated at the rear of the carriage. The return circuit from the solenoid is formed by arranging for the latter to be earthed. The core of the solenoid operates the lower member 118 of a dog clutch by means of intermediate levers 107, 111, 113. The keyway in the lower clutch member 118 is larger than the key in the clutch shaft 127 to ensure the teeth being completely engaged before the shaft is caused to rotate. The upper member 120 of the clutch is loose upon the shaft 127 and is driven continuously from the lower rear wheel 17 of the carriage by a sprocket and chain drive 124 and a worm and worm wheel drive 122. A disc 130 with raised edges containing two diametrically opposed slots is also secured to the clutch shaft 127. A tooth depends from the clutch-operating lever 113 and this tooth normally engages one of the slots in the disc 130. The lever 113 is kept in its lower position by a spring 137, but on the operation of the push button in the control tower and the energization of the solenoid, this lever is lifted, the tooth withdrawn from the slot and the clutch engaged. By the time the other slot in the disc 130 has come beneath the link, the solenoid is de-energized. The spring 137 then disengages the clutch and the depending link enters the slot and locks the disc. The lure arm 14 thus always has the same angular movement.