US2039114A

US2039114A - Device for suspending tools

Info

Publication number: US2039114A
Application number: US703857A
Authority: US
Inventors: Daniel J Reed
Original assignee: AO Smith Corp
Current assignee: AO Smith Corp
Priority date: 1933-12-23
Filing date: 1933-12-23
Publication date: 1936-04-28
Anticipated expiration: 1953-04-28

Description

DEVICE FOR SUSPENDING TOOLS Filed Dec. 25, 1933 0 WWW-' 0 INVENTOR.

Daniel J. Reed ATTORNEY.

Patented Apr. 28, 1936 UNITED STATES PATENT OFFIfiE DEVICE FOR. SUSPENDING TOOLS Daniel J. Reed, Milwaukee, Wis., assignor to A. 0. Smith Corporation, Milwaukee, Wis., a corporation of New York Application December 23,1933, Serial No. 703,857

2 Claims.

them easily portable or movable to various positions by an operator for performing the desired Work.

The object of the invention is to provide a mechanism of the class described which will re- .quire less effort on the part of the operator in moving and operating the tool and which will support the tool for more rapid movement in various directions.

Another object is to provide a simple inexpensive device for supporting heavy tools in a portable manner.

Other objects will appear hereinafter.

The preferred embodiment of the invention is illustrated in the accompanying drawing in which:

Figure 1 is a side elevation of the device;

Fig. 2 is an enlarged view on line 2-2 of Fig. 1;

Fig. 3 is an enlarged side elevational view of the pivot mechanism of the device with parts broken away.

The device has a depending pivotally suspended arm I at the lower end of which is a pivoted member 2 having a flexible cable or chain 3 secured thereto and supporting a yoke 4 to which the tool 5 is secured.

The arm I is preferably suspended from a trolley 6 riding on the overhead track 1. The arm I has a forwardly extending member 8 at its upper end and upwardly extending ears 9 adapted to cooperate with downwardly extending ears Ill on the trolley 6 to receive a pivot pin H for supporting the arm I. The pin ll extends longitudinally of the trolley 6 so as to provide for lateral pivoting of the arm I.

The pivoted member 2 has its axis at right angles to the axis of the pin II and is mounted on a horizontal pivot pin l2 in .a yoke l3 at the lower end of the arm I. The pivoted member 2 has a semi-circular central portion i4 over which a cable or chain 3 is secured. The chain 3 is fastened to the member 2 at the lower right hand corner and is allowed to hang freely from the left side of the member, so that as the chain is pulled downwardly, it will effect a pivoting or tipping of the member 2 counter-clockwise, as it appears in the drawing.

The lower end of the chain 3 passes through an opening in a clevis l5 and has a head l6 by means of which the clevis I5 is suspended. The clevis I5 is secured to the center of a cross arm H from the ends of which the tool supporting either side of the central portion M.

links 98 are suspended constituting the yoke 4. The mounting for the tool is universal, and the tool can be swung into any position, angular, horizontal, or vertical, as desired.

In order to balance the pivoted member 2 against the weight of the yoke 4 and tool 5, a pair of strong tension coil springs I9 are provided and-secured by means of cables or' chains 20 to eccentric portions 2| of the member 2 on springs I9 extend upwardly adjacent the arm I and are secured at the upper end to a clamp 22 adjustable in height on the arm I. Adjustment of the clamp 22 is effected by means of the threaded rod 23 extending downwardly from the member 8 and passing through the clamp, and a nut 24 on the lower end of the rod. After ad- J'ustment the clamp 22 is tightened in place on the tubular arm I by means of the bolt 25.

The specific shape of the eccentric members 2| is dependent upon the characteristics of the springs I9 and also upon the shape of the central portion M of the pivot member 2. As shown in the drawing, the shape of the members 2! provides a maximum distance of leverage of the chains 20 from the fulcrum of members 2i when the tool 5 is in its raised position and the springs iii are least tensioned, and provides a progressive reduction of the leverage as the tool 5 is drawn downwardly and the springs 19 are increased in tension. The result is a compensation for the varying tension of the springs [9 by a proportionate reduction of their leverage on the pivot member 2, making movement of the tool 5 equally easy without regard to its position. The same result may be obtained as readily by making the member I4 eccentric so as to increase the leverage of chain 3 as the tool 5 is drawn downwardly thereby compensating in part, at least, for the increasing in the tension of the springs I9. Thus, either member H5 or members 2! may be made eccentric or they both may be eccentric and designed to cooperate to provide the desired compensating action.

In the machine constructed in accordance with the drawing, although the tool 5 weighs several hundred pounds, it may be repeatedly pushed around and lowered to desired levels without fatiguing an operator working for several hours at a time. The several parts are preferably constructed to effect a static balance of the tool in any position. Therefore, any position of the device may be considered its normal position, and where the upper position of the tool is recited as The being normal in the claims, it is not meant to preclude other positions as normal.

A stop pin 26 extends transversely through the central opening 21 in the part M of the pivot member 2, between the arms of the yoke l 3. The function of this pin is to limit the pivotal movement of the member 2 and to prevent the tool from dropping in case a coil spring should break. The turn cable is employed herein in its broader sense to mean a rope, wire cable, chain or any equivalent flexible suspension member.

Although the invention has been described in its specific embodiment, it is to be understood that various embodiments may be made within the scope of the invention as defined in the accompanying claims.

I claim:

1. A device for suspending a tool for different relative work positions, comprising a depending arm, a member pivoted on a horizontal axis at the lower end of the arm and having a curved upper surface concentric to the axis, a cable passing over said surface and having one end secured to the member and the other end freely hanging to support the tool, said pivoted member also having an eccentric portion, a tension coil spring extending downwardly adjacent said arm having its upper end secured to a clamp adjustably fastened to the arm and having its lower end secured by a cable to the eccentric portion of said pivoted member at a point approximately the maximum distance from the fulcrum or horizontal axis of the pivoted member, the eccentric portion of said pivoted member decreasing the distance from the second named cable to the fulcrum as said member is pivoted in a direction tending to increase the tension of the spring.

2. A device for suspending a tool for different relative work positions, comprising a depending arm, a member pivoted on a horizontal axis at the lower end of the arm and having curved outer surfaces for receiving cables, a cable passing over the surface of said member and having one end secured to the member and the other end freely hanging to support the tool, a second cable having its lower end secured to a surface of said member at a point normally on the opposite side of the axis from the secured end of said first named cable, and a tension coil spring fixed at its upper end and having its lower end fastened to the upper end of said second named cable to insure a biasing force upon said pivoted member to suspend the weight of said tool, the outer surface of said pivoted member being shaped to provide a cam surface for at least one of said cables to change the leverage thereof with respect to said pivoted member for the purpose of compensating for the varying tension of said spring.

DANIEL J. REED.