US2489947A - Safety device for conveyer supports - Google Patents

Description

Nov. 29, 1949 L, c. BACKART 2,489,947

SAFETY DEVICE FOR CONVEYER SUPPORTS Filed Oct. 1, 1945 INVENTOR LLOYD C. BAG/(ART Patented Nov. 29, 1949 UNITED STATES PATENT OFFICE SAFETY DEVICE FOR CONVEYER SUPPORTS Lloyd 0. Backart, Grand Rapids, Mich, assignor to The Rapids-Standard Company, Inc, Grand Rapids, Mich., a corporation of Michigan 7 Application October 1, 1945, Serial No. 619,592

Claims.

This invention relates to a safety device for a conveyer having a vertically adjustable supporting frame and more particularly to a safety device which may be incorporated into the construction of such a frame to prevent its improper collapse.

The conventional type of mobile gravity and/ or power conveyer is usually manually adjustable through a range of varying heights and degrees of inclination. Injuries have, from time to time, resulted from the use of this type of conveyer by the improper collapse of the support. In one type of such conveyer a pair of rails is fitted with a collapsible support which is secured in any desired manner to form a rigid holding thereof at a desired vertical adjustment. This is usually done by means of a pair of fastenings, one on each side of the rails, which must be manually operated. If a careless operator negligently reaches under the support to loosen for lowering the far side without first making certain that the near side is tightened, the rails may collapse and catch a portion of the operators arm or body between the rails and the support. It is one of my aims to prevent this hazard by means of a device which will render the support only partially collapsible, which may be readily added to any such conveyer now in use, and which is simple and economical to manufacture.

Therefore, a principal object of my invention is to provide a safety device for use on conventional conveyers which have a collapsible support.

A further object of this invention is to provide a safety device for use on a conventional type of collapsible support for a conveyer, which device will prevent injuries which otherwise may occur when said conveyer is poorly adjusted.

Another object of this invention is to provide a safety device which may be adapted to conveyers having a wide range of support mechanisms and which may be readily added thereto.

Another object of this invention is to provide such a safety device which comprises few movable parts and which is economical to manufacture.

The details of my invention may be seen from the accompanying drawing. wherein:

Figure 1 is a fragmentary perspective view .of one type of gravity conveyer and its collapsible support fitted with an adjusting mechanism and. my improved safety device.

Figure 2 is a fragmentary front elevation of the spring and pivot of the safety device installed in place.

Figure 3 is a view, mostly in a cross-section, taken on the line IIIIII of Figure 2.

Figure 4 is a fragmentary side elevation of the spring and pivot.

This invention comprises an improvement on the adjustable type of collapsible support for a conveyer, one type of which is described in Reissue Patent 23,079, essentially as shown in Figure 1. Referring then to this figure, a conveyer of this type comprises a pair of rails, in and H, spaced apart evenly by a plurality of shafts l2 welded to the rails. These shafts are each encased by a free running roller I3 over which the work is conveyed from the upper to the lower end of the conveyer by the force of gravity.

This conveyer is equipped with a retractable support by which the height and/or angle of inclination of the conveyer may be varied. Referring again to Figure 1, this support comprises a pair of tubular frame or leg members l4 and I5 which are spaced apart in a parallel manner by at least two transverse tubular members l6 and l'i. The upper transverse tubular member I6 is rotatably disposed between the rails Ill and II. The lower transverse tubular member I1 is provided with a pair of rollers l8 which provide mobility to the conveyer.

' The rightward end of the conveyer proper, as shown in Figure l, is provided with a transverse tubular member l9 which is rotatably disposed within channel bar housings 20 and 20a at either end, each housing being longitudinally slidable on the rails l0 and II. Independent manually operable gripping means for holding these housings in selected positions on the rails is provided by gripping cams. The respective housings are connected by a cooperating shaft 22. The gripping cams on each side are moved as desired by independent means, as cranks, of which one appears at 2|. Further details of construction of this type of conveyer, support and holding means to which my invention is applicable may be found in U. S. Reissue Patent 23,079.

A supporting member or second leg in the form of longitudinal link member 23 is supported at its upper end by being pivotally mounted onto the housings 2i! and'20a in any convenient manner as by being welded to the tubular member I9 which pivotally surrounds a bar welded between said housings. Its other end is connected to a tubular casing 24, which, is in turn, rotatable about a shaft 25. This shaft is immovably connected to the longitudinal frame members l4 to the frame members I 4 and I5.

26a of said frame members. A flat coil spring 21 is bent at the extreme inner end and hooked over a bead 28 projecting outwardly from the surface of the tubular casing 24, and held at its outer end by a curved portion hooked over a spring holding shaft 29. Tension on this spring may be secured and adjusted by placing each adjacent end of the spring holding shaft 29 into one of a plurality, as three, openings contained in a rounded flange 30 welded to and downwardly extending from each of the tubular members 14 and i at points close to the points of fastening of the lugs 26 and 26a. In the preferred form shown, these flanges are each opposite thesupporting frame member l4 or IE from the corresponuing lug 26 or 26a, respectively. With the means which grip the slidable housings 2i] and 26a to the side rails properly loosened, the conveyor including said side rails is in a position to move downwardly upon a normally, freely collapsing frame. As it does so the link member 23 will rotate upon its pivot clockwise with respect The spring will oppose but not prevent this motion. A corresponding spring 2'la may be similarly installed at the other end from spring 211 of the sleeve 24.

If the springs are normally shaped so that they will be but slightly distorted when the adjustable frame is in its full upward position, it will be found that the installation of these springs may be effected quickly and easily. These springs may be selected of such stiffness that they will balance the weight of the conveyer at any desired point. I have found, however, that it will require a pair of springs of only moderate size to support the weight of an unloaded conveyer of usual size when the supporting members have moved to an approximately half-way collapsed position. At this point the above mentioned rotation of the link 23 with respect toframe members l4 and i5 will have placed sufiicient tension upon the springs that further such rotation will be resisted so long as the collapsing motion is'induced by only the normal weight of the ordinary conveyer. With balance secured at this point, an operator may easily move the conveyor proper upward with the aid of the springs or push it further downward against the springs and hold it in the desired position with one hand while with the other hand he sets the manually operated gripping means on at least one side.

Since the major load of the conveyer is taken by the springs and since the conveyer cannot, of its own weight, fall beyond a predetermined and known balance point, the operator can move the conveyer frame at will upwardly or downwardly and be secure in the knowledge that it will not fall into a fully collapsed condition if it should happen to slip out of his immediate manual control.

It will be evident also that this safety device will function as means for assisting the ease with which the conveyer may be adjusted upwardly or downwardly.

Various modifications may be made in the above described device all of which will be included within the hereinafter appended claims excepting as said claims by their own terms expressly provide otherwise.

I claim:

1. Safety means for conveyer supporting frame members wherein one of said members is mounted to another of said members for pivotal movement with respect to each other as the body of said conveyer is adjusted upwardly and downwardly, said means comprising: a resilient element coiled upon itself and positioned co-axially with the point of pivotal attachment of said members with respect to each other, the inner end of said element held against motion with respect to one of said members and the outer end held against motion with respect to the other of said members, said element resiliently opposing such relative pivotal movement as the body of said conveyor is adjusted downwardly.

2. A safety means associated with conveyor construction having a conveyor frame supported by a pair of leg members attached to each other at a point substantially removed from said conveyor frame for pivotal movement relative to each other, the end of one member of said pair being pivoted to a member slidably adjustable along a member of the conveyor frame, and the end of the other member of said pair pivotally affixed to said conveyor frame; said safety means comprising: a resilient member under tension aflixed at one part thereof rigidly with respect to one of said leg members and affixed at another part thereof rigidly with respect to the other of said leg members, the urging of said resilient member opposing pivotal separation of said leg members about said point of pivotal attachment as said conveyor frame is adjusted downwardly.

3. Safety means for a conveyor having a pair of rails spacedly secured together and means supporting said spaced rails at selectively and adjustably variable heights, said supporting means comprising: a first leg member secured at its upper end in pivotal relationship to one of said rails, a second leg member pivotally and slidably secured at its upper end to said rail and pivotally secured to said first leg member at a point spaced from said upper end; said point of pivotal attach ment of said first leg member and said second leg member being spaced from the upper end of said first leg member, said leg members moving pivotally with respect to each other as the said rails are moved upwardly and downwardly; the safety means comprising: a resilient element coiled upon itself, the inner end of said element held against motion with respect to one of said leg members, and the outer end held against motion with respect to the other of said leg members, said element resiliently opposing relative pivotal movement of said leg members as the body of said conveyor is adjusted downwardly.

4. Safety means for a conveyor supporting frame wherein said supporting frame includes a leg member and a link member, said link member mounted on one of its ends to said leg member at a point substantially removed from either end of said leg member for pivotal movement relative to said leg member as the body of said conveyor is adjusted upwardly and downwardly, said link member on the other of its ends slidably mounted to the body of said conveyor, said means comprising: a resilient member coiled upon itself and positioned .co-axially with the point of pivotal attachment of said leg member and said link member, the inner end of said element held against motion relative to said link member, the outer end of said element held against motion relative to said leg member, said element resiliently opposing pivotal motion of said leg member and link member relative to each other as the body of said conveyor is adjusted downwardly.

5. Safety means for a conveyor supporting structure wherein said supporting structure includes a leg member pivotally attached at a point substantially removed from each of its ends to a upwardly and downwardly; a helical resilient member co-axial with said shaft and having its inner end held against motion relative to said shaft and its outer end engaging and held against motion relative to said bar, the positioning of said resilient member being such as to cause said resilient member to oppose relative movement of said leg member and said supporting member as the body of the conveyor is adjusted downwardly.

LLOYD C. BACKART.

No references cited.

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