Patent GB-249913-A (GB)
Title: Improvements in phonographs
IPC: G11B17/02
Filed: 1924-12-22
Abstract: 249,913. Dehn, F. B., (Carnes Artificial Limb Co.). Dec. 22, 1924. Multiple machines; raising, positioning, and lowering sound box; returning sound-box to starting-point; feed-motions; tone-arm joints.-Relates to gramophones of the kind in which a series of records can be played automatically and in continuous succession, the records being transferred in turn from a carrier to the turntable by a lifting-device and, after being played, replaced in the carrier. In a machine according to the invention, the record carrier is an endless chain device, which, as shown in Figs. 2 and 14, consists of a pair of - sprocket chains B<4> passing over pairs of parallel wheels B<1>, B<3>, the links of the chains being provided with upstanding arms b, b<1> to which segmental cross-bars b<2> are riveted. The records b<3>, b<4> are supported vertically between the crossbars on the upper horizontal part of the endless carrier thus formed. Record-gripping and lifting devices E<2>, E<3>, one of which is shown in Fig. 19, each consist of a dished plate near the periphery of which are pivoted three pairs of hooks e<1>, e<2>. These are connected together and to a central spindle E<4> by links, a spring (not shown) acting on the spindle and tending to hold the hooks in the position in which they can grip a record pressed against the plate. The outer set of hooks are for engaging a large record and the inner hooks for holding a smaller one. The plates are hinged at D<4> to brackets D<2>, D<3>, mounted on shafts D, D' which are journaled transversely of the framework of the machine, Fig. 1. Suitably placed springs tend to swing the brackets D<2>, D<3> upwardly and springs D<5> maintain the hinges D<4> normally open as shown in Figs, 1, 19. Passing through each hinge is a pin d<5> which bears against a bell-crank lever E<5> linked to an arm on the spindle E<4> of the record-gripper. This mechanism serves to open the hooks when required, to release a record, under the action of the cam-shaft mechanism subsequently described. The pivotal support for the wider end of the tonearm comprises an internal spider carrying a vertical tube which surrounds a fixed tube projecting up from the neck of the horn. The machine is driven by a continuously-running motor through a main shaft H, upon which are freely mounted sleeves H<1>, H<4>, between which is a clutch sleeve H<2>, rotating with but slidable upon the shaft H. When the sleeves H<2>, H<4> are in engagement, the turntable is driven through a worm H<7>, and a transverse shaft M, Fig. 1<a>, is also driven through a worm H<6>. This shaft has splined upon it a sleeve having screw threads m<6> which normally, when the shaft M is rotating, engage a gear segment O<3>. The latter, together with an arm N<2>, is rotatably mounted between the arms of a U-bracket 0 hinged to the framework, and the arm N<2> is linked through members N<3>, N<5> to a sleeve secured to the wider end of the tone-arm. By means of this mechanism the sound-box is positively fed across the record on the turntable. A shaft L, on which is mounted a series of cams 1 - - 11 is driven from the main shaft through a worm-wheel L<1> when the clutch sleeve H<2> is shifted from engagement with the sleeve H<4> to mesh with the sleeve H<1>. The cams 1 - - 5 and 7 - - 11 co-operate with bellcrank levers 1<a> - - 5a and 7a - - Ila mounted on a fixed shaft L<3>. The lever 1<a> is connected through a rod n<2>, Fig. 5, to the swinging bracket O, so that when operated by the, cam 1 it effects the disengagement of the segment O<3> from the feed-screw m<6> and at the same time causes the rods N<2>, N<3>, N<5> to swing the tone-arm back across the record, the sound-box having been previously lifted. This lifting is effected by the lever 2<a>, which is connected through rods P, P<1>, and a cord R<11> passing up through the horn, Fig. 5, to a lever K<1> acting upon the short jointed end of the tone-arm. The levers 3<a> and 11<a> are connected in similar manner through rods P<2>, P<8> to bell-crank levers f which act through levers f<2>, F, Fig. 19, upon the pins d<5>, to control the recordgripping hooks. The levers 4a, 10<a> are connected through rods P', P<7> respectively to levers f<1>, f<3>, associated with each of the record-lifting devices E<2>, E<3> to cause them to pivot about their hinges D<4> over the turntable at the proper times. The levers 5a, 9<a> are connected through rods P<4>, P<6> respectively to the brackets D<3>, D<2> to swing about their axes D<1>, D so as to lift a record from or replace it in the carrier, as subsequently described. The lever 7<a> serves to operate, through a rod p<5> and a pawl-bearing arm p<3>. Fig. 5, a ratchet-wheel C which is frictionally engaged between two discs c<1>, c<2> on a shaft B<2> on which the sprocket-wheel B<3> is mounted. This effects the intermittent movement of the record-carrier. The lever 8<a> operates, through suitable link-work, a plate R, Fig. 14, which presses each record in turn into engagement with the gripping-hooks of the lifter E<2>. The device for shifting the clutch sleeve H<2> between the sleeves H<1>, H<4> comprises a fork Q<1> on a shaft Q, Figs. 1<a> and 5, which bears a lever 6a. This lever is moved in one direction, to cause the sleeves H<2>. H<1> to mesh, by engagement therewith of a lug m<1> on a sleeve M<2> which is normally stationary on the shaft M. The cam 6 on the shaft L reverses the movement of the lever 6a at the proper time and thereby causes the clutch sleeve H<2> to be shifted back to transfer the drive to the sleeve H<4>. Means are provided for automatically determining the extent of movement of the arm N<2> each time the segment O<3> moves back into mesh with the feedscrew m<6>, according to whether a small or large record is on the turntable, so that the proper starting-position for the sound-box is ensured. The segment O<3> can also be prevented by a lever T, Fig. 5, from meshing with the screw m<6>, so that the automatic action of the machine can be stopped. In order that single-sided records can be used on the machine it is necessary to cut a circular groove on the plain side of such records, so that when this side is uppermost on the turn. table the needle will enter the circular groove and cause the record-changing mechanism to function. For the purpose of cutting such a groove on either a large or small record, there is provided an arm V<1>, Fig. 5, having two cutting tools V<2>, V<3>, and rollers V, V<5>. The arm is pivoted at V, and can be turned when required to cause the appropriate cutting-tool to act upon a record on the turntable. The operation of the machine as a whole is as follows, assuming that a small record has been placed on the turntable by hand, and the upper part of the record carrier is filled with records, alternately large and small. The segment O<3> having been brought into gear with the feed-screw m<6> and the sound-box having been lowered on to the outer zone of the record on the turntable, the cam shaft L is stopped by the action of the cam 6. The clutch sleeve H<2> is then in mesh with the sleeve H<4>, causing the turntable to be driven and the screw m<6> to feed the tone-arm and sound-box across the record. At the end of the playing, the gear O<3> engages a stop u, Fig. 1<a>, the needle at the same time entering a circular groove at the inner end of the sound groove. This results in the screwed sleeve m<6> sliding into engagement with the sleeve M<2>, whereby the cam lever 6<a> is actuated as previously described, and causes the clutch H<2> to be shifted and transfer the drive through the sleeve H<1> to the cam shaft L. The cam 2 then effects the lifting of the sound-box from the record, and the cam 1 causes the bracket O, segment O<3>, and arm N<2> to rotate, whereby the sound-box is swung back across the record. The cam 5 then acts to rotate the record gripper E<3> through a right angle in its own plane, whereupon the gripper is lowered over the turntable by the action of the cam 4, and the hooks e<1>, e<2> are allowed to grip the record under the action of their spring. The cam 4 next allows the spring D<5> to raise the record-gripper E<3>, together with the record held by it, and the record is then transferred to the carrier, into which it is released when the cam 3 causes the gripping-hooks to open. Then the cam 7 acts to cause the carrier to move forward one step, and the next record to be played is moved against and held by the gripper E<2>. By the action of the cams 9 and 10, the gripper E<2> is then swung upwardly in its own plane and turned so as to bring the record over the turntable, and the record is freed from the gripping- hooks by means of the cam 11, and deposited in the playing position. Finally the empty gripper E<2> is restored to its position over the carrier, and the sequence of operations starts afresh.