US2735538A

US2735538A - boehm

Info

Publication number: US2735538A
Authority: US
Publication date: 1956-02-21
Anticipated expiration: 1973-02-21

Description

I -h In,

Feb. 21, 1956 Filed March 4, 1954 W. G. BOEHM COIL. UNLOADER 5 Sheets-Sheet l INVENTOR.

w/u 716A 6. BOAHM BY ATTORNEYS Feb. 21, 1956 w. G. BOEHM 2,735,538

con UNLOADER Filed March 4, 1954 3 Sheets-Sheet 2 fiw 7 7 m TZM/IUJLHT Feb. 21, 1956 w. G. BOEHM 2,735,538

COIL UNLOADER Filed March 4, 1954 3 Sheets-Sheet 5 IN VEN TOR.

W191 725? 6. BOA-HM Uni States M COIL UNLOADER Walter G. Boehm, Birmingham, Mich., assignor to Jervis B. Webb Company, Detroit, Mich a corporation of Michigan Application March 4, 1954, Serial No. 414,074

4 Claims. (Cl.198209) This invention relates to improvements in the construction of a coil unloader, a device employed for the handling of annular bodies such as coils of Wire, rod, or strip.

In most mills such coils are conveyed from the area where they are formed to a storing or shipping area on hooks of an over-head conveyor. The coil unloader of the present invention is a device employed for receiving coils from this over-head conveyor, and for accumulating or storing a group or bank of coils which are then removed from the unloader by other means for shipment or storage.

The construction of the present coil unloader is de signed to facilitate both the operation of receiving coils from the over-head conveyor, and also the operation of removing coils from the unloader after a bank has been accumulated. Briefly, the construction of the unloader includes a stationary base structure or pedestal which forms a support for a vertical drive shaft and a table connected for rotation therewith. A series of coil handling arms project radially from the center of rotation, each arm being connected to the table on a horizontal pivotal axis. A cam track forms part of the base or pedestal structure, and is contacted by a follower on a crank forming part of the structure of each of the coil handling arms. These cam track and crank elements are arranged so that at one station to which the table is rotated, each coil handling arm is elevated in an inclined position to receive coils from the hooks of the over-head conveyor by gravity. In other positions of rotation of thetable the coil handling. arms are moved to a lowered position to facilitate the operation of unloading the coils accumulated on each. Means are employed for driving the rotating table, and a system of controls is included for correlatingthe operation of the driving means with the operation of the over-head conveyor so that after one coil handling amt has been filled with coils, an empty arm is advanced into coil receiving position.

One embodiment of the invention is disclosed in the accompanying drawings, this showing the construction of a coil unloader equipped with six coil handling arms. These drawings comprise the following views:

Fig. 1, a plan view of the coil unloader.

Fig. 2, a sectional elevation of the construction, taken along the line 2-2 of Fig. l, and including in phantom a showing of a portion of an over-head hook type of coil conveyor in position to deposit a coil on one of the arms of the unloader.

Fig. 3, a sectional plan view taken along the line 3-3 of Fig. 2.

Fig. 4, a schematic showing of the unloader driving means and controls.

Referring to Figs. 1 and 2, the base assembly. of the structure includes a base plate 10, an outer cylindrical column 11, and an inner conical column 12, being welded to the base plate 10. An upper circular plate 13 is supported upon the columns 11 and 12, and has a central aperture 14. An aperture 15 is likewise provided in the 2,735,538 Ce Patented Feb. 21,1956

base plate 10 in vertical alignment with the aperture 14. A drive shaft 16 extends through the two apertures15 and 14, being carried by a thrust bearing assembly mounted on the base plate 10 and generally designated by the reference 17, and a plain bearing 18 is mounted in a bearing block 19 Which is bolted to the upper plate 13. The base plate 10 is designed to be supported, when the unit is installed, upon a concrete and steel foundation.

A rotary table assembly is supported upon the upper plate 13 and is connected in driven relationship with the shaft 16. This assembly is designed to pivotally mount six coil handling arms, and comprises a plate 21 which is generally hexagonal in plan. Six wheels 22 are se cured to the underside of the plate 21 for contact with a circular track 23 mounted on the upper surface of the plate 13.

Six hinge assemblies are mounted upon the upper surface of the plate 21. Each of these hinge assemblies is composed of a pair of vertical side plates 25, having portions 26, extending radially from the center of the plate 21 and mutually parallel portions 27 which are connected by a vertical cross member 28. Gusset plates 29 connect the lower edges of the parallel portions 27 and the cross member 28. The radial portions of the side plates 25 are connected to an upper horizontal plate 30 of hexagonal configuration, which is also supported on the lower plate 21 by an inner cylindrical column 31. Connection of the rotary table to the shaft 16 is through a bearing block 32 which is secured or bolted to the upper hexagonal plate 30 and connected to the shaft by a key 33. This assembly is heldon' the shaft by a thrust cap 34' which is fastened to the head of the shaft by bolts 35. The hinge axis of each hinge assembly is defined by holes 37 formed through the parallel portions 27 of each of the side plates 25 and through washers 38 which are welded to the inner face of each of the plates 25 to augment the bearing area on the hinge axis.

A coil handling arm assembly is mounted on each hinge axis. These assemblies are identical, each including a back-plate 40 which is reinforcedby a box structure composed of a pair of vertically extending ribs 41 inter-connected by

cross member

43 and 44. An inner plate 45 connects the two ribs l'l above the cross member 43. A clevis construction (Fig. l) is employed for the hinge points, being formed by an car 46 provided on each of the ribs 41 and by a similarly shaped'member 47 which is secured to the inner plate 45 inwardly from the ribs and in parallel alignment with the ear portions therotary table by a pair of pivot pins 55 which define a horizontal pivotal axis for each coil handling arm. That portion of the back-plate construction of each arm assembly which extends below the axis of the hinge pins 55 may conveniently be considered as a crank, and the lower end thereof is equipped with a roller follower 56, mounted on an axle 57 'supportedbetween a pair of plates 58'. v

A cam track 60 is provided on the base of the machine. A portion of this cam track is concentric with the axis of rotation of the shaft 16, being secured to the cylindrical supporting member 11. The remaining portion of the cam track 60 is supported by a laterally extending inclined plate 62 which forms and defines an eccentric or nose portion of the cam track. Plate 62 rests upon the base plate 10, its ends 63 are secured to the cylindrical member 11, and its nose portion 64 is rigidly supported by braces 65 extending back to the cylindrical member 11. The inclination given to theplate 62 is directed generally towards the horizontal hinge axis of each arm assembly; in other words, this inclination is such as to position the surface of the cam track 60 substantially parallel to the back-plate 40 of the arm assembly along all points of contact between the roller follower 56 and the cam track 60.

In Fig. 3, the direction of motion of the roller follower 56 along the cam track 60 is indicated by the arrow 66, and it can thus be seen that the portion 67 of the cam which defines upward movement of the arm assemblies is sharper than the portion 68 thereof which defines lowering movement. Lowering of a loaded arm assembly is accomplished with a more gradual, gentle motion than is the upward movement of an unloaded arm.

Rotary movement of the turn-table and arm assemblies is intermittent, and this operation is correlated with the operation of the overhead coil conveyor by a suitable system of controls such as schematically illustrated in Fig. 4. Shaft 16 of the coil unloader is driven from the out-put shaft 70 of a reducer 71 which in turn is driven by a suitable motor 72. Operation of this motor 72 is intermittently controlled by a rotary limit switch 73, shown as driven from the shaft 70 by a pair of

sprockets

74 and 75. The limit switch 73 operates the motor 72 to rotate the shaft 16, A of a revolution or 60 degrees at a time, and is adjusted so that the shaft 16 is stopped by an electrically energized brake (not shown) forming part of the motor 72, when each arm assembly has been rotated to raised or loading position.

An electrical tie-in is included between the control circuit for motor unit 72 and the coil conveyor, which correlates the actuation of the motor with the position of the coil carrying hooks 77 on the conveyor and with the number of coils deposited from the conveyor onto the arm of the unloader. This electrical tie-in includes limit switches LS1 and LS2 positioned to be contacted by the hook carriers 77 of the coil conveyor, together with, suitable auxiliary electrical components arranged to accomplish the mode of operation outlined below. These auxiliary components have not been shown in detail, since they are standard electrical items and since their arrangement is a matter well within the capabilities of those skilled in this art.

Assuming that the unloader assembly has been rotated to place one of the arms thereof in the upwardiy inclined loading position such as indicated by the arm 59a in Fig. 2, five coils are dumped onto the arm from the overhead conveyor by operation of a hook tip-up mechanism thereof which forms no part of the present invention. After the carrier or hook 77 bearing the fifth one of these coils has contacted LS1 and is between LS1 and LS2, a circuit is set up which will release the brake of the motor unit 72 and start the motor after the carrier has contacted LS2. LS2 thus functions to signal that a coil is free of its hook. Motor 72 will then be started and will operate until the shaft 16 has been rotated A5 of a turn or 60 degrees, at which time the motor will be stopped and its brake energized by operation of the rotary limit switch 73. This advances a following arm 56 into upwardly inclined loading position. If for any reason, the unloader does not operate properly to rotate a loaded arm out of the way and replace it with an empty arm, a safety factor is provided by LS1, and also by the method of normally loading a lesser number of coils on the arm than its length will accommodate. LS1 is connected so that its actuation by an approaching coil will prevent operation of the motor 72. Thus, if after five coils have been loaded on the arm and the motor 72 has not started by the time the next successive coil reaches LS1, the motor will not start, but the successive, or sixth coil will be deposited on the arm. LS1 senses any departure of the system from the pro-determined sequence of operation, and can also be employed to stop the over-head conveyor in case it is contacted by a carrier while the unloader is still on its cycle of movement, or is in motion.

Operation of the unloader in service has shown an appreciable saving in the handling time required for unloading coils from a conveyor, and also for removing them from the unloader for shipment or storage. The unloading operation between the conveyor and the arm assembly is much smoother and results in less damage to the coils. This operation is also made more positive and safe, reducing the possibility of a coil being dropped from the over-head conveyor onto the floor.

It is recognized that many possible modifications can be made in the construction shown while retaining the advantageous features thereof, and, therefore, the scope of this invention is not to be considered as limited otherwise as required by the terms of the following claims.

1 claim:

1. In a coil unloader having a pedestal base structure, a turntable rotatably mounted thereon, and means for rotating said turntable; a purality of coil handling arm assemblies, means for connecting each of said coil handling arm assemblies to said turntable in radial relation to the rotational center thereof for pivotal movement about a substantially horizontal hinge axis; cam means carried by said base in vertically spaced relation to said turntable, said cam means including a portion concentric with the axis of rotation of said turntable and a portion eccentric thereto; and means for supporting each of said arm assemblies and for controlling pivotal movement thereof about said hinge axis in response to rotation of said turntable to cause each arm assembly to be raised to an upwardiy inclined loading position and to lower and maintain said loaded arm assembly at a substantially horizontal unloading position, said means including said cam means and a back plate rigidly secured to each arm transversely thereof adjacent said hinge axis, said back plate serving to define the position of a load on said arm and having a crank portion extending to one side of said pivotal axis, said crank portion being provided with a cam follower contacting said cam means.

2. A coil unloader according to claim 1, wherein the base structure includes a base plate and a vertical cylindrical member supported thereby, said cylindrical member being mounted with its axis concentric with the axis of rotation of said turn-table, so as to form the said concentric portion of said cam means, and structural means including said cylindrical member for supporting said turn-table.

3. A coil unloader according to claim 1, wherein the said eccentric portion of said cam means includes a curved plate carried by said base structure, said plate providing a cam surface progressively inclined toward the hinge axis of each arm assembly as the eccentricity of such cam surface increases.

4. A coil unloader according to claim 3, further characterized by the length of the cam surface on the rise of said eccentric portion being less than the length of said cam surface on the fall of said eccentric portion.

Spears Aug. 19, 1902 Schreiber May 23, 1944