GB1124901A - Controls for material handling apparatus - Google Patents

Abstract

1,124,901. Control of several motors. TRIAX CO. 23 Aug., 1965 [3 Feb., 1965], No. 34034/65. Heading H2J. [Also in Division B8] Apparatus for transporting palletized loads to and from bins 13, Fig. 1, in a storage frame 10 comprises a carriage 16 movably mounted on a track 17 and carrying a turn-table 18 from which depends a column 19, and an elevator 20 mounted for vertical movement on the column 19 and carrying forks 23 which are horizontally movable into and out of the bins, the forks being provided with means such as a pressure switch 56, Fig. 2, for sensing whether or not a load is disposed on the forks and for accordingly effecting the movement of the latter. The bins 13 are provided on both sides of a central aisle along which the track 17 extends. The carriage 16 is driven by a motor Mx, the elevator 20 is driven by a motor MZ through a chain drive 21, 22, and the forks 23 are moved by a motor MY which rotates a worm 31 engaging a threaded collar 32 connected to a scissor-like parallel linkage 33 to which is secured the forks 23. The turn-table 18 may be motor-driven or moved manually. The apparatus is automatically controlled for movement of loads between the bins 13 and a start position at one end of the aisle. Movement of the carriage 16 along the aisle is controlled by a counter switch 24 which is sequentially operated by trips 25 and vertical movement of the elevator 20 is controlled by a counter switch 26 operated by trips 27. The control system, Fig. 2, comprises mechanical or electrical counting mechanisms PRCY, PRCX, PRCZ controlling the motors to move the forks into a selected bin from the start position and similar mechanisms PRCY<SP>1</SP>, PRCX<SP>1</SP>, PRCZ<SP>1</SP>, for returning the forks back to the start position. The mechanisms, when electrical, are preset by a dial operated switch device 40. Command devices CD, CD<SP>1</SP> determine whether the forks 23 are moved to pick up a load or deposit a load. The devices CD, CD<SP>1</SP> are controlled through a relay 59 by operation or otherwise of the switch 56. A further use of the switch 56 is to operate a relay 61 controlling contacts 62 disposed between the motor MZ and the devices CD, CD<SP>1</SP>; when a load is picked up the motor MZ is stopped. The forks 23 also carry a switch 70 for stopping the motors if an attempt is made to deposit a load in an occupied bin. In a second embodiment, Figs. 3, 4, the forks are provided with switches 81, 82, 83 for respectively detecting an obstruction at the tip of the forks, a load resting on the forks, and an obstruction adjacent the side walls of the forks. The switch 82 is operated by depression of a pivoted, spring-loaded plate 90 and the switch 83 by a feeler 96. A controller device 100 controls operation of servo devices for the motors. A braking device 110 and an alarm 111 are operated upon activation of the switches 81, 83. Operation of the switch 81 may be used to return the forks to the start position, Fig. 5 (not shown). In a further embodiment, Fig. 6 (not shown), the switches 81, 82, 83 are replaced by photo-electric scanning devices. The switch 82 is replaced by a device (136) scanning upwardly, the device comprising a light source (137) and a photoelectric cell (138) so that a load deposited on the forks operates the device by reflecting the light from the source (137) back to the cell (138). The switch 81 is replaced by a photo-electric cell (140) adapted to remain activated by ambient light. Upon movement of the forks towards an obstacle the cell (140) becomes deactivated. A device similar to the device (136) or the cell (140) replaces the switch 83.