US3016151A - Hoists - Google Patents

Description

Jan. 9, 1962 B. c. EISENBERG HOISTS 5 Sheets-Sheet 1 Filed Feb. l, 1960 INVENTOR. 5642/144199 C se/11564,@

Jan. 9, 1962 B. C. EISENBERG HOISTS 3 Sheets-Sheet 2 Filed Feb. l, 1960 me En@ wm JNVENTOR.

-qo C. 65e-"Beye ArrOQn/svs Jan. 9, 1962 B. c. EISENBERG 3,016,151

IN V EN TOR. fmwo C fsf-Neffe Arme/vers 3,t16,151 Patented Jan. 9, 1962 3,016,151 HOISTS Bernard C. Eisenberg, Brooklyn, N.Y.

(P1). Box 567, Caldwell, N.J.) Filed Feb. 1, 1960, Ser. No.5,992

2 Claims. (Cl. 212-135) This invention relates to an improvement in hoists for transferring work between tanks containing various solutions used in metal-plating processes.

Work to be metal plated is placed on suitable racks or jigs. The racks holding the work are hungy along a work bar. This work bar is manipulated to move the work hung from it from one tank to another. Each end of the work bar fits into a guide rest mounted on each end of the tank top. When the work bar is resting on the tank, the suspended racks together with the material to be metal plated are immersed and correctly positioned in the tank solution. To transfer the work to the next tank in the metal-plating process the work bar is lifted vertically until the suspended racks and work are free from the tank. The work bar is then shifted horizontally until directly over the neXt tank, then lowered into the tank guide rests. Care must be taken that the Work suspended from the work bar does not touch the sides of the tank during immersion.

It is diilicult to move a work bar manually because of the combined weight of work bar, racks, and work. In a metal-plating installation some type of hoist is provided. The present inventor was the-first to introduce the use of rigid-frame hoists in metal-plating processes. The rigid frame is suspended by trolleys from overhead tracks and contains various parts of the hoisting mechanism. The rigid frame provides stable guidance of the work bar as it is raised and lowered, reducing the possibility of accidental `Contact of work with the tank side. The rigid frame is easily moved horizontally along its supporting overhead tracks to its proper position over the next tank.

However, rigid-frame hoists as first employed were not entirely satisfactory. The present invention is directed to the solution of the problems encountered. Among the problems were the following: The mechanism for raising and lowering had to be contained in a very small volume within the rigid frame, yet had to be capable of providing relatively large vertical movement. It was a practical requirement that the lifted work bar be tilted at a slight angle to facilitate drainage of the plating solution from the work. The work bar mustbe returned to a horizontal position when placed on the tank guide rests. When the hoist is movedalong curved sections of the overhead track binding is apt to occur. The work bar required insulation from the hoist to prevent short-circuiting under certain conditions. It was discovered that the common methods of facilitating simple mechanical functions in the hoist were inadequate to the extreme wear and tear the hoist was subjected to.

Accordingly, it is an object of this invention to provide a unitary device which eliminates the problems noted above. Another object is to provide an improved hoist which may be used efficiently by relatively untrained personnel. Another object of this invention is to provide a hoist appropriately adapted to the requirements of metal-plating processes. Another object is to provide a suitable means for raising and lowering work bars.

Another object is to provide a means of raising and lowering work bars which automatically maintains work.

bars at a slight angle whenever lifted above the guide rests of the tank. Still another object is to provide a hoist suitable for manipulating work bars used in metalplating which may be moved along overhead tracks by manual or power driven means.

Briefly stated, this invention provides a hoist vfor eicient employment in a metal-plating installation having a series of tanks containing various solutions. Tracks are located above the tanks and provide support and means of moving the hoist horizontally. The invention is comprised of trolleys running on the overhead tracks, a rigid frame which is suspended from the trolleys, va cross-bar which may be moved up and down within the frame, and air-operated piston and associated pulleys and cable chain for moving the cross-bar, a spring device` for tilting said cross-bar automatically when work is lifted from a tank, an air-operated motor for driving the hoist assembly along the overhead tracks, together with suchmodiiications and mechanical improvements that operate to make the hoist practical and efficient.

For a better understanding of the invention, particular description is given below.

In the drawings: y Y

FGURE l is a side elevation view of the hoist showing details of construction; and t f FIGURE 2 is a vpartial isometric view of the hoist showing operating portions of the lifting mechanism; and

FIGURE 3 is a top view of the hoist showing details of construction; and

FIGURE 4 is a cross-sectional View showing means of attaching lifting hooks to the cross-bar.

References are made tothe same item numbers in each figure.

" The' frame of the hoist is comprised of horizontal ltop bar 1 and vertical channel bars 2 and 3. Top bar 1 is A preferably fashioned into a U-shaped cross section for rigidity and strength, the size of the U being large enough to accommodate equipment mounted therein. Connected to one end of top bar 1 at right angles is channel bar 2. Connected to the other end of top bar 1 is channel bar 3. Channel bars Z and 3 are bolted, welded, or attached by other suitable means to top bar 1 and both extend downwards from top bar 1.V Channel bars 2 and 3 together with top bar 1 comprise a rigid frame. Both channel bars 2 and- 3 have U-shaped cross sections for structural rigidity and strength. The open end of the U of each assemblies 4 and 5.

A vertically movable cross-bar 6 is supported at its ends by roller assemblies a and 5 being attached thereto by means of exible fastenings 7 and S respectively which may each consist of a single bolt or rivet. Roller assemblies 4 and 5 are adapted to move in the U-shaped tracks of channel bars`2 and 3 respectively, serving to maintain movable bar 6 at any desired vertical position within the frame comprising top bar 1 and channel bars 2 and 3.

To the cross bar 6, near each end are attached lifting hooks 9, which are adapted to Vgrasp work bar 10. Work bar 16, when not supported by lifting hooks 9 is supported by holders ,11 at'either end of an immersion tank. Lifting hooks 9 arev insulated from cross-bar 6 by insulating bushings 12 rnade of nylon or other suitable material. Bolts 13 attach lifting-hooks 9 to cross-bar 6. insulation of the liftin'ghooks 9 from the cross-bar 6 prevents grounding out-vof the metal-plating system under certain conditions, such as when more than one hoist is in operation in the same metal-plating installation.

Cross-bar 6`is raised and lowered by means of chain cable 14 fastened to roller assembly 4 and chain cable 15 fastened to roller assembly 5. Movement is ytransmitted to chain cables 14 and 15 from a pneumatic cylinder 16 channel bar faces inwardly'so as' to accommodate roller incorporating a double pulley 17 and 18 rigidly attachedV to the single shaft 19 operated by the piston of cyhnder 16. In the embodiment shown, chain cables-14 and 15 are reeved through the double pulley 17 and 18 in such a manner as to produce twice the chain movement at thel roller assemblies l4'- and 5 as is traversed by piston shaft 19. This achieves the purpose of providing adequate vertical movement to cross-bar 6 from piston shaft 19. VMovement of shaft 19 is limited by space and consideration of mechanical stability when extended fromcylinder 16.

Chain cable 14 connects from the top of roller assembly 4, upwards in the U of channel bar 2 to pulley 20 mounted by its axis in top bar 1, over the top of pulley 20 making a 90 bend, continuing towards pulley 17 mounted by its axis to shaft 19, over the top of pulley 17 and returning under the bottom making a 180 turn, to anchor 21 on the body of top bar 1.

Chain cable 15 connects from the top of roller assembly 5 upwardsin the U of channel bar 3 to pulley 22 mounted by its axis in top bar 1, over the top of pulley 22 making a 90 bend, continuing across the entire length of top bar 1, reeving over the top of pulley 23 mounted on the same axis with pulley Ztl, and returning under the bottom of pulley 23 making a 180 turn, returning towards pulley 13 mounted on the same axis with pulley 17, reeving from under up over pulley 18 making a 180 turn, to one end of shaft 32. The other end of shaft 32 is connected to one end of spring 24, whose other end is fixed to anchor 25 on the body of top bar 1.

The tension of spring 24 is such that it remains compressed when no work bar is loaded on the lifting hooks 9. The result is that the cross-bar 6 is level while lifting hooks 9 are empty. However, when the work bar is raised on the lifting hooks 9, the increased weight on chain cable causes spring 24 to be extended. Thus chain cable 14 lifts roller assembly 4 a few inches before spring 24 has stretched to the point where stop collar 33 mounted on shaft 32 engages fixed bracket 34. After spring 24 has been stretched to this limit, chain cable 15 begins to lift roller assembly 5. Thus cross-bar 6 is tilted by the advance of roller assembly d before roller assembly 5 starts to move. This tilt facilitates drainage of residual liquid on work items after their removal from the tank.

Pneumatic cylinder 16 is operated by air control 26 mounted at the operators side of the hoist. When crossbar 6 is to be raised, air is admitted into cylinder 16, causing the piston of cylinder 16 to extend shaft 19 outwards from cylinder 16. Pulleys 17 and 1% are mounted on a common axis within a forkattached to shaft 19. Thus pulleys 17 and 18 are moved away from cylinder 16 by the motion of shaft 19. The action of pulley 17 upon chain cable 14 is as follows: For each inch of travel of pulley 17 away from cylinder 16, one inch of chain cable 14 appears between pulley 17 and anchor 21. This inch of chain cable 14 movement is reeved through pulley 17. There is also relative motion of chain cable 14 occasioned by the increasing distance between pulley 17 and roller assembly 4. The result is two inches of actual movement of chain cable 14 between pulley 17 and roller assembly 4. Thus roller assembly 4 is pulled upwards 2 inches for every inch the piston shaft 19 of cylinder 16 is extruded by air pressure.

The action of pulley 1S upon chain cable 15 is as fol# lows: For each inch of travel of pulley 18 away from cylinder 16, two inches of chain cable 15 are taken up between pulley 18 and roller assembly 5 if there `is no load on the lifting hooks 9. If a load exists on lifting hooks 9, the roller assembly acts as an anchor and movement of chain cable 15 causes spring 24 to be extended. When spring 24 is extended to the point where stop collar 33 mounted on shaft 32 engages fixed bracket 34, stop collar 33 acts as an anchor, causing travel in the section of chain cable 15 between pulley 18 and roller assembly 5. Chain cable 15 raises roller assembly 5 by reeving through pulleys 22, 23, and 18 to spring 24.

Trolley assemblies 27 and 2S are attached on each side of top bar 1. Each'trolley assembly consists of two sets of steel flanged wheels29 and 30, each set on an assem.

bly separated by a distance suiiicient to maintain top bar 1 and thus the hoist at right angles to the overhead tracks. The steel wheels 29 and 30 are adapted to ride on the upper surface of the lower horizontal cross piece of l-beam '31 which acts as a track. Trolley assembly 27 is solidly xed to top bar 1. Trolley assembly 28 supports top bar 1 by means of a roller assembly 32 suspended from trolley assembly 28 and engaging a short horizontal channel 33 in top bar 1. The freedom of relative movement between trolley Z7 and trolley 2S allows the hoist to be moved along curved tracks without binding on a curve. Trolleys 27 and 28 are so. located on top bar 1 so as to insure continually-progressive movement of the side of the hoist nearest the inside of a curved section (not shown) ofi-beam tracks. Thus leverage may be applied to the inside of the hoist While the hoist is centered in a curved section of overhead track and the entire hoist will respond by moving through the curve.

An air-operated motor (not shown) may be mounted with trolley assembly 27, adapted to drive a set of rubber tired wheels, in a well known manner. Gperation of the motor causes the rubber wheels to turn, thus driving the trolley and the hoist along the overhead tracks.

Following is a typical example of operation of the hoist. To remove work bar 10 with its racks and work from a tank of a metal-plating process land move it to the next position the following series of steps are taken. The hoist is horizontally moved along the overhead tracks until it is over the tank containing the desired Work bar and work.. Air control 26 is then actuated to cause downward movement of crossbar 6. Air control 26 is maintained thusly until lifting hooks 9 attached to cross bar 6 are in a position to engage work oar 1G. Then air control 26 is turned olf. Care is taken that the hoist is horizontally positioned so that the open side of lifting hooks 9 face work bar 10. When the fingers or lifting hooks 9 are slightly below work bar 19 the hoist is slightly moved horizontally by means of trolley assemblies 27 and 2S so that the fingers of lifting hooks 9 are underneath work bar 11i. Then air control 26 is actuated so asto cause cross-bar 6, together with work bar 10 resting on lifting hooks 9, to rise. Air control 26 is .maintained thusly until the lowest parts of the work emerge from the tank and are free to move horizontally. The work is allowed to drain briefly before the hoist is moved horizontally to the next position which may be another tank or a conveyor for removing work bar 10 together with the plated wo-rk on it. Finally, work bar 10 is lowered onto another set of holders (not shown) similar to holders 11, and the lifting hooks, freed of their load, are disengaged. The hoist is then free to perform another operation.

What is claimed is:

l. 1n a hoist for moving articles relative to the tanks of a metal-plating apparatus, the combination of two horizontal tracks positioned above said tanks, trolley means operating on each of said tracks, a rigid vertical frame comprising a horizontal top bar and'two vertical channel bars attached thereto supported by and movable with said trolleys and one of said trolleys being movable with respect to the other trolley, roller assemblies each contained and movable within one of said channel bars, a substantially ho-rizontal movable cross bar supported by and pivotally attached to said roller assemblies and bearing insulated supporting means, air-operated means for raising and lowering said cross bar comprising an airoperated cylinder horizontally mounted with said top bar adapted to impart motion from its piston shaft to said roller assemblies and cross bar in-such a manner that greater verticalmotion is imparted to said roller assemblies and cross bar than is horizontally traversed by said piston shaft, and tension .loading spring means for automatically tilting said cross bar from its horizontal position when said bar is elevated from its lower-most position and is loaded by a weight supported on said supporting means. l

2. 1n a hoist for moving articles relative to the tanks of a metal-plating apparatus, the combination of two horizontal tracks positioned above said tanks, trolley means' operating on each of said tracks and suspended therefrom,

arigid vertical frame comprising a horizontal top bar t and two vertical channel bars attached thereto Supported by and movable with said trolleys and one of said trolleys being lixed to said top bar and the other trolley being movable with respect to s'aid top bar, roller assemblies each contained and movable within one of said channel bars, a substantially horizontal movable cross bar supported by and pivotally attached to said roller assemblies and bearing insulated lifting hooks, means for raising and lowering said cross bar comprising an air-operated cylinder horizontally mounted with said top bar yadapted to impart motion from its piston shaft to said roller assemblies and cross bar by means comprising cables in such `a manner that greater vertical motion is imparted to said roller assemblies Iand cross bar than is horzontaly traversed by said piston shaft, and spring actuated tilting means comprising Ka spring inserted between one 0f said cables and its` anchor for automatically tilting said cross bar from i-ts horizontal position when said cross bar is elevated from its lowermost position and is loaded by article-s supported on said hooks.

References Cited in the le of this patent UNITED STATES PATENTS 1,049,839 Fraser Jan. 7, 19'13 1,941,767 Towson Jan. 2, 1934 2,245,673 Huenerfauth June 17, 1941 2,706,565 Krasno Apr. 19, 1955 2,707,053 Browning Apr. 26, 1955

Images