Handling: hand and hoist-line implements – Hook – hoistline – or grab type – Driven positioning mean
Reexamination Certificate
2001-08-17
2003-02-11
Ellis, Christopher P. (Department: 3652)
Handling: hand and hoist-line implements
Hook, hoistline, or grab type
Driven positioning mean
C212S242000, C212S251000
Reexamination Certificate
active
06517131
ABSTRACT:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
REFERENCE TO A “MICROFICHE APPENDIX”
Not Applicable
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a rotary device which is used for rotating a suspended load. In particular, the present invention relates to a rotary device which has a boom which connects to a material handler vehicle for rotating a load lifted by the material handler vehicle.
(2) Description of the Related Art
The ability to lift and rotate suspended loads with precision control greatly enhances any lifting operation. To rotate a suspended load safely, the rotating force must be controlled. Controlling the rotating force eliminates the possibility of applying unforeseen twisting forces to the rigging (chokers, slings, etc.). Controlling the rotating force also reduces the amount of damage or harm produced should the rotating load which is being lifted come in contact with a fixed object or structure.
In the past, to rotate a suspended load such as during steel erection, a tag line and tag line person were used. This process involved controlling a suspended load by tying a rope to one (1) end of the load being lifted. However, attempting to control a suspended load from the ground can have numerous safety hazards. In addition, in some cases where the load is lifted high, obstructions to the tag line or the tag line person make the use of a tag line impossible. In this case, the operator must bump the load against some existing structure or object to try to get the load correctly positioned once the load is hoisted.
The related art has shown various types of load rotating devices which allow for slippage should the load encounter an obstacle. Illustrative are U.S. Pat. No. 2,823,944 to Anderson et al; U.S. Pat. No. 3,037,804 to Kraeling et al; U.S. Pat. No. 3,046,046 to Gris; U.S. Pat. No. 3,210,115 to Graham et al and U.S. Pat. No. 3,633,961 to Speransky.
Anderson et al describes a motorized swivel hook device. The swivel hook of the device has a vertical shank which is connected to a thrust collar extending between a flange at the bottom of the shank and the underside of a roller bearing. An annular flange of the thrust collar overlies the hub of a driven gear. The driven gear connects with a drive gear positioned on an output shaft of a speed reducer. The upper and lower faces of the flange of the collar are sandwiched between the driven gear and a plate. Friction material is interposed between the flange and the driven gear and the flange and the plate. By tightening nuts on bolts extending through the driven gear, flange and plate, a predetermined amount of frictional force is provided between the driven gear and plate on one hand and the thrust collar on the other hand. Thus, when the rotating hook encounters a resisting force exceeding the frictional force exerted on the flange, the gears will be able to rotate, with the driven gear and the plate frictionally slipping relative to the flange.
Kraeling et al describes a rotary hook for a traveling block for cranes. The crane hook block is comprised of the sheaves and the hook swivel which are secured to each other by means of parallel links. The rotary drive for rotating the hook relative to the block is provided with a friction clutch to prevent destruction of the gear drive if the hook is accidentally struck against an object and caused to twist which will cause the clutch to slip rather than destroy the apparatus. Thus slippages occur between the hook nut which is connected to the spindle of the hook clevis and the ring gear which is rotated by the pinion on the end of the output shaft of the gear reducer. Springs are used to provide sufficient compression to provide a friction drive between the upper and lower faces of the ring gear and the friction clutch linings. One (1) friction clutch lining is located between the lower face of the ring gear and the shoulder of the hook nut. The other friction clutch lining is located between the upper face of the ring gear and the pressure rings which hold the springs.
Gris describes a motor activated rotary crane hook. In each embodiment the hook is connected to the upper member by a swivel connection which allows for manual rotation of the load when necessary. The object of this invention is to provide a power means for rotating the hook in relation to its upper member. In each embodiment, the motor acts to rotate the hook directly. The hook does not rotate with the shaft.
Graham et al describes a power rotatable hook device which includes a torque limiting means such that if the load meets an obstruction, the torque limiting device would slip which would enable the motor to continue running. When the obstruction is removed, the load resumes rotation. The torque limiting means is of the slip type and can be of the eddy current type. The torque limiting device is selected so that it will slip at a torque value less than that which the speed reducer can safely handle.
Speransky describes a crane hook rotated by power for proper load orientation. The invention includes a hollow shaft which is connected to a shank extension of the shank of the hook. An electric motor rotates the hollow shaft and the hook. A plunger is slidably mounted in the shaft and an insert is disposed between the upper end of the shank extension and the lower end of the plunger. The upper end of the insert has a keyway within which is disposed a radial key carried by the lower end of the plunger. This key has tapered sidewalls so that the key will ride out of the keyway should the hook encounter turning resistance.
Also of interest are U.S. Pat. No. 3,009,728 to Breslav and U.S. Pat. No. 5,125,707 to Chaen et al.
Breslav describes a rotatable load supporting or lifting device. The speed reduction device used in rotating the hook includes a worm gear and worm shaft. A friction clutch is located on the worm shaft to drive the worm under ordinary conditions. The clutch allows slippage between the motor and the worm when the worm meets an obstruction.
Chaen et al describes a rotary load lifting device which allows for remotely operating the driving device provided on a hook block which is connected to a load lifting hook. The driving device and hook block each have chain wheels which are connected together by a chain.
There remains the need for a rotary device which includes a telescoping boom for mounting on a material handler vehicle and which uses the weight of the load to produce friction between the driven shaft and the load to rotate the load while controlling the amount of friction so that if the load should encounter an obstacle during rotation, the frictional force will be overcome and the load will stop rotating.
SUMMARY OF THE INVENTION
The present invention relates to a unit having a boom and a load rotary device which is used to rotate a suspended load in a controlled manner. In one (1) embodiment, the unit includes a boom with a hydraulically powered, suspended load rotary device. The rotary device includes a first bracket fixably mounted to the boom. A second bracket is movably mounted to the first bracket. The first and second brackets each have V-shaped or triangular shaped openings. The brackets are connected together by a U-shaped, cylindrical connector which extends through each of the openings. The shape of the openings and the shape of the connector allows the second bracket to swing freely with respect to the first bracket. A motor bracket is mounted to the second bracket by a spacer. The spacer and motor bracket are mounted on a side opposite of the first bracket. The motor is mounted on the motor bracket such that the motor shaft extends downward through the motor bracket. The drive gear is mounted on the end of the motor shaft. A driven shaft extends from the second bracket through the spacer and motor bracket and through a third bracket rotatably mounted on the second end of the driven shaft. A driven gear is fixably mounted on the driven shaft between the motor bracket and the third bracket. The motor
Chin Paul T.
Ellis Christopher P.
McLeod Ian C.
Moyne Mary M.
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