US 3084820 A
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Description (OCR text may contain errors)
April 9, 1963 w, Q
CLAMP FOR CASE CARRYING TRUCKS Filed April 14, 1960 INVENTOR. WiLLIAM 6' MALO Wc'ZZlwnum-n, J
A 7' TOPNE KS United States Patent Ofitice 3,084,826 Patented Apr. 9, 1963 3,084,820 CLAMP FOR CASE CARRYING TRUCKS William G. Mala, Marshall, Mind, assignor of one-half to Rolland Sherman, Marshall, Minn. Filed Apr. 14, 1960, Ser. No. 22,338 7 Claims. (Cl. 214371) This invention relates to industrial hand trucks adapted for carrying cases of bottled goods and frequently referred to as beverage case trucks.
An important object of my invention is an industrial hand truck which is capable of picking up and transporting a stack of cases of bottled goods without requiring that the stack of cases be initially tipped to mount the cases on the truck.
Another object is a new and improved case clamp or gripping means adapted for use with a case carrying truck which is designed to grip a case of bottled goods at the usual apertures provided for the handholes to positively maintain and support a stack of cases of bottled goods on a hand truck during transportation thereof.
Another object is a case gripping and carrying clamp of the class described which is substantially noiseless in operation and provides for a more positive clamping of the cases than has been heretofore possible.
Still another object is a case clamp of the class described which is adapted to engage cases of varying widths within reasonable tolerances or limits to enable said clamp to work efficiently and permit a single truck having the clamp of the instant invention mounted thereon to be employed in carrying cases having a variance in span between th handholes.
A further object is a case carrying truck having novel simply designed, easily mounted, relatively inexpensive case gripping and supporting means which are responsive to contact with the cases to be carried and automatically enclose and support said cases when coming into contact with same in a smoother, noiseless and more effortless fashion than heretofore possible with prior art devices.
These and other objects and advantages of my invention will more fully appear from the following description made in connection with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views, and in which:
FIG. 1 is a side elevation of a preferred embodiment of my invention shown in cooperative relationship with a stack of cases of bottled goods, the full line position showing the stack as it is initially grasped and the broken line position illustrating the position of the truck and stack of articles during tilted transportation position;
FIG. 2 is a section taken approximately on the line 2--2 of FIG. 1;
FIG. 3 is a somewhat diagrammatic top plan view of the case gripping and supporting clamp shown in FIGS. 1 and 2 illustrating the approximate extreme open and closed positions thereof with portions thereof broken away;
FIG. 4 is a somewhat diagrammatic top plan view of an alternate form of my invention showing the clamp in its approximate extreme closed and open positions; and
FIG. 5 is a partial rear elevational view of the alternate form of invention illustrated in FIG. 4.
Reference is now made to the accompanying drawings for a more detailed description of my invention. The main body portion T of the truck body upon which my case gripping and supporting assembly or clamp is mounted may be of any suitable design. A preferred type of truck body is illustrated in the accompanying drawings and consists of a generally inverted U-shaped frame of rigid tubular construction and includes the vertical side members 10 which are interconnected by a series of vertically spaced slightly rearwardly bowed cross bracing members 11, with a rearwardly extending handle member 12 provided at the top of the U-shaped frame. A pair of rearwardly extending bowed or arcuate shaped skid members or stair climbers 13 are connected as by welding to each of the side members 10 to enable the truck to be conveniently slid up and down stairways and the like.
The stair climbers 13 have secured thereto as by welding a transversely disposed foot piece 14 which also serves as the axle for mounting the rubber tired wheels 15 thereon.
The case gripping and supporting assembly or clamp constituting the instant invention includes a pair of similar case gripping jaws, arms or clamping members 16, 'which arms include the forwardly extending side portions 16a adapted to enclose the sides of the cases 17, the back portions 16b disposed at approximately right angles to the side portions 16a and adapted to be disposed opposite and enclose the backs of the cases 17 to be transported, and
the rearwardly extending offset end portions 160 upon which the arm tensioning and actuating means are adapted to be mounted. These offset end portions 160 are preferably slightly bent back upon the back portions 16b at an angle on the order of 5% or inclined slightly towards the sides and disposed at an angle somewhat less than degrees with respect to the back portions 16b, preferably at an angle on the order of 85 degrees with respect thereto for a purpose hereinafter to be described.
The arms 16 are pivotally mounted on the truck frame by means of bushings or collars 18 which are mounted on the side members 10 near the lower extremities thereof and somewhat above the extreme lower end or foot thereof and above the lower join between the stair climbers '13 and the side members 10. This enables the arms 16 to be disposed at approximately the same height as the hand hold apertures 19 of the cases 17 and in substantial alignment therewith.
The outer or leading ends of the side portions 16a are provided with inwardly projecting lateral extensions or ears 20 which are adapted to be inserted into the hand hold apertures 19 of the cases 17 to positively support and lift the cases.
Novel elongate, elastic or resilient tensioned clamp arm teusioning and actuating means are provided in the form of a strong helically coiled spring 21 in FIGS. 1-3 inclusive which spring extends between and engages these rear offset portions 16c and is secured thereto by any suitable means such as the nutted bolts 22. Cylindrical guide or insert members 23 are inserted axially into the outer ends of the spring 21 and surrounded by several convolutions thereof to provide for more positive actuating engagement between the spring 21 and the arms or jaws 16. The spring is axially compressed to suitably tension same and cause it to naturally assume a bowed or flexed position and continuously bear or push against the offset portions to which it is attached and bias or hold the arms 16 in one direction or the other (towards open or closed position) depending on the relative position of the spring with respect thereto, the medial portion of the spring being capable of and adapted to flexing or yeilding to assume the bowed positions shown in the accompanying drawings as dictated by the relative positions of the clamp arms 16 with respect to each other, the medial portion of the spring tending to follow the course of least resistance when subjected to axial compression or compressive forces and buckling in one direction or the other, depending on whether the clamp arms 16 are open or closed and holding said arms in one of said positions.
The spring 21 provides what might be termed an overcenter action for moving and maintaining the arms inwardly or outwardly depending on which side of the center line cl the spring is disposed. The center line referred to is the line extending between and bi-secting the points of pivotal connection of the arms with the truck frame or the axes of pivotal movement of said arms. It will be noted that the center portion of the helical spring 21 is free to move laterally in any direction, and it will be readily appreciated by those skilled in the art that a compressively tensioned helical spring tends to bow outwardly at the center portion or point of least resistance thereof to relieve the compressive tension thereon. Therefore, when the spring 21 is disposed forwardly of the line cl bi-secting the collars 18 (as shown by the broken line position of FIG. 3), the clamping and supporting arms is are held outwardly and positively maintained in that position until the spring is moved rearwardly past the center line (as shown by the solid line position of FIG. 3) at which time the spring bows towards the rear and pulls the arms inwardly into clamping, supporting position. Thus, the helical spring 21 provides for positive clamping action and also provides a positive means for maintaining the arms in an outwardly disposed inoperative position. In addition to the positive clamp controlling action provided by the spring, the spring also has other important advantages in that it provides for very smooth substantially noiseless operation with no banging or clanging of metal parts taking place.
In use and operation, the truck with the arms or jaws 16 of the carrying clamp in the outwardly extended broken line position of FIG. 3 is moved against a stack of cases 17 which movement may be assisted by the operator pushing against the foot piece 14-. As the back portions 16b of the arms J16 engage the back of the lowermost case, they are pressed rearwardly causing the side arm portions 16a to move towards the sides of the case and cause the engagement and supporting ears 2% to be inserted into the hand hold apertures 19 of the cases as best seen in FIG. 2. As the spring 21 reaches the center iine cl between the points of pivotal connection, it re- Verses position and moves or bows rearwardly, and at the same time applies positive pressure against the offset end portions 160 and continuously urges them apart, thereby positively holding the side portions 16a against the sides of the case and maintaining the supporting ears 20 in the hand hold apertures 19 and insuring that they will remain there. The offset end portions 16c may be maintained or disposed at right angles to the back portion 16b to maintain the spring 21 in substantially straight alignment. However, as previously described, I have found that a more positive clamping or retaining action is provided if the end portions 16c are slightly angularly offset from the back portion 1612 by approximately degrees which causes the spring in clamping position to bow rearwardly as best seen in FIG. l2, thereby eifecting a more positive locking and clamping action than would otherwise be provided and eliminating any possibility of the arms becoming inadvertently disengaged from the cases prior to the lifting and transporting thereof.
Bottle carrying cases vary somewhat in size depending on the manufacturer thereof and to allow for this variance in size, the carrying clamp or case gripping assembly of my invention is adapted to maintain a positive gripping action for engaging and supporting the smaller cases in which the side arms 16:: are disposed somewhat inwardly and converge slightly towards one another and tending to assume the solid line position of FIG. 3. However, due to the positive action or thrust applied by the rearwardly bowed spring 21 in such a circumstance, the arms and the ears 20 are positively held against the case to engage the same and prevent slippage thereof.
When the cases have been transported to their destination, the truck is tilted to a substantially upright position to permit the cases to rest on the floor and the truck is twisted slightly with respect to the stacks causing the arms 16a and the ears carried thereby to disengage from the case and cause the arms 16 to be pushed to the outwardly extending inoperative broken line position best seen in FIG. 3, the spring 21 moving forwardly past the center line and bowing forwardly to positively hold the arms 16 in open position.
FIG. 4 illustrates an alternate form of gripping assembly of my invention which employs the same basic principles as those of the gripping assembly hereinbefore described, but varies somewhat in the actual construction and design thereof. In this alternate form, a transverse clarnp supporting bar 24 is secured to the front of the feet of the side members it as by welding and extends laterally outwardly therefrom a short distance. A pair of vertically disposed rod-like pivot or bearing members 25 are carried on the outer ends of said supporting bar 24 and have pivotally mounted thereon and encompassed thereby a pair of clamp carrying sleeves 26. The sleeves 26 have secured thereto as by welding the clamping arms or jaws 27 which include the forwardly extending side portions 270 and the back portions 2711, the leading ends of the side portions 27a being provided with inwardly laterally extending case carrying and supporting cars 28 adapted to be inserted into the hand hold apertures '19 of the cases 17. The inner ends of the back portions 2711 have mounted thereon as by welding mounting members or rods 29 which extend in from and beyond the outer ends of the back portions 27b, the extended portion of the mounting rods 29 being adapted for insertion into the ends of an elongate resilient semi-rigid deformed or bowed tensioned arm coupling and holding member 30, the mounting rods 29 being provided with raised, lateral portions 31 for anchoring the arms 27 to the tensioned member 39. The inner ends of the back portions 27b preferably abut with the outer ends of the tensioned member 30 to provide a more positive action therebetween.
The tensioned member 30 operates in much the same fashion as the helical spring 21 previously hereinbefore described and also operates on what might be termed an over center principle. The tensioned member 30 is adapted to bow laterally outwardly under the bending stress or tension applied to the ends thereof and when disposed rearwardly of the center line between the points of pivotal connection (as defined by the bar 24) positively holds the side arm portions 27a and the cars 28 carried thereon inwardly in a positive clamping action and when disposed forwardly of the center line positively maintains the side portions 27a in an outwardly extended open inoperative position corresponding to the broken line position of FIG. 4. Thus, the coupling member 30 may be an elongate semi-rigid elastic element or tube of any suitable cross sectional shape and made of rubber or some other suitable material which, when bent or deformed as in the accompanying drawings, resists such deformation or bending to such an extent that it is tensioned sufficiently to positively hold the carrying and clamping arms 27 in whatever position desired while still being resilient enough to be able to shift position or spring from one side of the center line to the other under the influence of the movements of back portions 27b of the carrying arms 27.
In view of the foregoing, the advantages of my invention are readily apparent. A beverage case truck employing the case supporting and carrying clamp of my invention can readily pick up and disengage a stack of cases without first tilting the cases, thereby avoiding the physical exertion, inconvenience and possible danger of tipping over the cases and breaking the contents commonly associated with tilting a stack of cases. The tensioned coupling members whether of the coiled spring variety or the elastic bar stock type provide for substantially noiseless operation and further provide for smooth and efficient and positive holding of the arms in all positions including clamping and open inoperative position to maintain the case engaging arms either in a positive clamping engagement with the cases to be carried and supported thereby or to positively maintain them in an outwardly extended open inoperative position. It will also be noted that the arrangement provides for automatic shifting of the arm biasing and tensioning members 21 and 30 from one side of the center line to the other when the arms 16 and '27 are moved by engaging the cases or by twisting movement applied to the truck.
It will be further appreciated that the case gripping assembly or clamp of my invention is relatively inexpensive to make and mount and may be readily adapted to almost every type of case carrying truck frame now available on the market.
It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the various parts without departing from the scope of my invention.
What I claim is:
l. Grasping and lifting apparatus comprising a frame, a pair of cooperating jaw members pivotally mounted on said frame for relative opening and closing movement therebetween for releasably holding an article therebetween, and spring means interconnecting said jaw members and movable therewith between a first position when said jaws are open and a second position when said jaws are closed, said spring means biasing said jaws in one direction about their respective pivot axes and away from each other and yieldingly holding said jaws open when in said first position and biasing said jaws in the opposite direction about their respective pivot axes and towards each other and yieldingly holding them closed when in said second position.
2. Grasping and lifting apparatus comprising a frame, a pair of jaw members pivotally mounted on said frame for relative opening and closing movement therebetween about parallel axes, and spring means interconnecting said members and moveable therewith and adapted to shift position from one side to the other of a line bisecting said axes when said jaws move between open and closed position whereby said spring means biases said jaw members away from each other and yieldingly holds them in open position when on one side of said line and biases said jaws towards one another and holds them in closed position when on the other side of said line.
3. Grasping and lifting apparatus comprising a frame, a pair of elongate jaw members pivotally connected intermediate the ends thereof to said frame for relative opening and closing movement therebetween, said jaw members having opposed first end portions adapted for movement towards and away from each other to grasp an article therebetween and second end portions offset from said first end portions and rigidly connected thereto and extending toward each other, and spring means interconnecting said second end portions, said spring means being adapted to move with said jaw members and shift position when said jaws are opened and closed whereby said first end portions are biased in one direction relative to their respective pivot axes and away from each other by said spring means when the jaws are open and are biased in the opposite direction relative to their respective pivot axes and towards each other by said spring means when the jaws are closed.
4. Grasping and lifting apparatus comprising a frame, cooperating jaw members pivotally mounted on said frame for pivotal movement about parallel axes, said jaw members having first end portions adapted to grasp an article therebetween and second end portions olfset from said first end portions and rigidly connected thereto and extending towards one another, a helically coiled spring member extending between and flexibly linking said second end portions together and compressively tensioned thereby, said spring member being adapted for shiftable movement between positions on opposite sides of a center line bisecting said axes of pivotal movement in response to the movements of said jaw members in moving from inoperative to operative position, said spring member biasing said first end portions towards one another when on one side of said center line and biasing said portions away from one another when located on the opposite side of said center line.
5. Grasping and lifting apparatus comprising a frame, cooperating jaw members pivotally mounted on said frame for pivotal movement about parallel axes, said jaw members having first end portions adapted to grasp an article therebetween and second end portions offset from said first end portions and rigidly connected thereto and extending towards one another, an elongate spring member extending between and flexibly linking said second end portions together and maintained in bowed tensioned condition thereby, said spring member being adapted for shiftable movement between positions on opposite sides of a center line bisecting said axes of pivotal movement in response to the movements of said jaw members in moving from inoperative to operative position, said spring member being bowed in one direction and biasing said first end portions towards one another when on one side of said center line and being bowed in the opposite direction and biasing said portions away from one another when located on the opposite side of said center line.
6. Grasping and lifting apparatus comprising a frame, a pair of cooperating jaws having elongate first end portions for grasping an article therebetween and elongate second end portions generally normal to said first end portions and rigidly connected thereto and extending towards each other, said jaws being mounted on said frame for pivotal movement about parallel axes normal to both of said end portions, said second end portions terminating in generally opposed ofiset portions extending in a direction opposite to said first end portions, and an elongate coiled compression spring extending between said offsets and having its ends anchored thereto for movement therewith, said spring being maintained in compressed tensioned state by said offsets and con tinuously pressing thereagainst, said spring being adapted for shiftable movement between positions on opposite sides of a center line bisecting said axes of pivotal movement in response to the movements of said jaw members in moving from inoperative to operative position, said spring biasing said first end portions towards one another when on one side of said center line and biasing said portions away from one another when located on the opposite side of said center line.
7 The apparatus of claim-6, wherein said offset portions are bent back upon said second end portion and define therewith an angle less than References Cited in the file of this patent UNITED STATES PATENTS 2,292,234 Malo Aug. 4, 1942 2,651,427 Butler Sept. 8, 1953 2,720,992 Cushman Oct. 18, 1955 2,954,886 Nelson Oct. 4, 1960 FOREIGN PATENTS 76,928 Netherlands Jan. 15, 1955