| 摘要 |
<p>608,264. Dental &c. equipment stands. RITTER CO., Inc. Jan. 29, 1946, No. 2906. Convention date, March 14, 1945. [Class 81(ii)] A stand for supporting dental, medical, &c. equipment comprises a pedestal or support, an instrument holder movable between positions where the instruments are accessible for use, and are enclosed respectively, and switch-controlled motor means for moving the holder. As shown. the pedestal 31 carries a casing 33 provided with a sliding cover 63 and in which moves the instrument holder 42. This is formed as a rectangular block provided with sockets 45 accommodating say an air syringe 48, lamp 49, cautery 50 and water syringe 51, each instrument being connected by a flexible cord, &c. 52, passing round a pulley 132 to a spring reel 144. A carriage 53 reciprocates within the casing on flanges 54, and in turn is formed with guides 55 on which the holder 42 may reciprocate. Outward movement of the carriage brings its guide 55 into contact with a lip 58 on the holder to move the latter to the position of Fig. 11. When the carriage is retracted the holder is moved inwards by its weight and by springs 59. The carriage however, travels further inwards after the movement of the holder has stopped, this additional movement being utilized to close the casing cover 63. This is effected through pivoted links 80, 83 carrying a roller 82 which engages a pivoted arm 73 co-operating with an arm 71 attached to the cover. The latter is provided with rollers 68 running on tracks 67. The means for reciprocating the carriage 53 comprises double-threaded spindles 84, 85 rotatably mounted on the casing, the two threads being joined at each end of the spindles. Bevelled threadfbllowers 94 are carried by plugs 95 rotatably mounted on the carrier, so that if the spindles are rotated continuously, the carrier reciprocates. The spindles are rotated by a motor 105 and a chain and sprocket connection 103, the motor shaft being provided with a solenoid-operated braking device 108. The electric circuit comprises a manually operated switch, the operation of which closes the motor circuit. A second switch 117 in parallel and attached to the casing is adapted to be opened by cam surfaces 121, 122 attached to the carriage. When therefore the carriage has moved a short distance from one of the extreme positions on closing the manually operated switch, one of the cam surfaces 121, 122 disengages, closing the switch 117, and movement continues to the other extreme position, when the switch 117 is opened by the other cam surface and the movement is arrested. The circuit is also such as to apply the solenoid-operated brake 108 when the motor is inoperative. A modification of the device is described, in connection with which U.S.A. Specification 2,328,924 is referred to, in which the flexible current and fluid conductors, instead of being taken up on reel 144, hang in a loop in the base of the device passing around pulleys on a vertically-slidable carriage.</p> |
