| 摘要 |
665,050. Conveyers. BAKER PERKINS, Ltd. (Baker Perkins, Inc.). Oct. 3, 1949. No. 25394/49. Class 78 (i). A band tracking device comprises power operated means for correcting a tendency of the band to move laterally, means including differential means operated by lateral movement of the band and by adjustment of the correcting means for anticipating cessation of lateral band movement and means actuated by the anticipating means for controlling the correction means. The band 25 passes round a drum 24 on a shaft 23 which is mounted in bearings on supports in a baking oven 10. The end bearing 21 is'slidable on a support 18 by a guide 26 when the band moves to contact a side roller 27. The rollers are connected by brackets to a rod 33 which is mounted in side bearings and extends into a housing 42 at one end. The rod 33 is linked by a bell crank lever and cross rod to a vertical rod 62 mounted to pivot about upper and lower points 61 and 65 and connected at its lower end to a block 64 threaded on a shaft 66. A U- shaped bracket 67 screwed to the rear wall 43 of the housing acts as a limiting device for movement of the rod 62. One end of the shaft is mounted in a bearing 90 and has a gear 93 meshing with a gear 94 on a shaft 95 driven from a motor 112. The shaft 95 is geared to a shaft 98 having a pulley, clutch and handwheel, the clutch is coupled to a lever 107 having a hand wheel for manual operation should the power supply fail. A rod 116 is connected between the bearing 21 and the shaft 95. The lever 62 passes between two switches 69 and 70 connected to the rear wall 43 and having rollers 71 and 72 contacting a cam plate 73 pivotally mounted on the rear wall 43 and to the lever 62 by pins 74 and 76. The switches are connected to reversing switches in switch boxes 81 and 82 and to limit switches 85 and 86. Lateral movement of the band contacts a roller to move the rod 33 to move the lever 62 and cam plate 73 to contact a roller on a switch 69 and 70 to operate the motor 112 to drive the rod 116 to laterally displace the shaft 23 to correct movement of the band. At the same time the shaft 66 is rotated to move the block 64 and lever 62 tu pivot about points 61 and to break contact with the switch and tu stop the motor, the speed at which this occurs depending on the rate of correction of lateral band travel. In a modified form, the shaft of the jockey pulley, over which the belt passes, is mounted to pivot at one end by mounting in a stub shaft and the other end is mounted in a carriage movable longitudinally on wheels. When a side roller is contacted, a vertical shaft is pivoted to operate a lever to close a switch to start a motor to move the carriage and the axle of the jockey pulley. This starts a differential device to open the motor circuit. The switches, operating similarly to those previously described, are mounted on separate plates hinged together and are adjustable to allow for greater tolerance of band movement. |
