US2459275A - Hand truck with stair climbing shoe - Google Patents

Description

Jan. 18, 1949. J. c. GATES HAND TRUCK WITH STAIR CLIMBING SHOE Filed Sept. 27, 1947 firm)? NEY.

23 INVENTOR) JOHN C. GAT 15y My Patented Jan. 18, 1949 UN lTED" STATES PATEN T 0 F F! CE 2,459,275 HAND-TRUCK STAIR' GLI'MBING-SHOE John 6.- Gates, Indianapolis, Ind. A plication September 27, 1947. Serial No. 776,459 4 Cl-aims. (01. 280-47) This invention relates to a hand truck and particularly to a mechanism incorporated thereto not only protect the forward edges of-the treads upon Stairways, but also to tacilita'te the lifting of the truck from one tread to the next. A- priniary object of the invention is to provide a truck of the nature for the purposes indicated whi'h the mechanism is exceedingly simple and automatic in repositioning itself. A further important object is to provide such a structure with a minimum number of parts assembled in an unique manner to be durable over long periods of usage and capable of being produced at a relatively low cost.

'These and other important objects of the invention will become apparent to those versed in the art in the following description of one particular form of the invention as illustrated in the accompanying drawing, in which Fig. 1 is a view in side elevation of the structure embodying the invention;

2, a view in front elevation;

Fig. 3 a view in top plan;

Fig. 4, a view in side elevation in a partially raised position;

Fig. 5, a detail in side elevation and partial section on an enlarged scale of the anti-friction shoe;

Fig. 6, a section on an enlarged scale on the line 6-6 in Fig. 1, and

Fig. 7, a longitudinal section on the line 1-1 in Fig. 6.

Like characters indicate like parts throughout the several views in the drawing.

In the present form of the invention, I bend a piece of tubing generally designated by the numeral ID, to have a cross bar portion II from the ends of which are downwardly turned rails I2 and I3, and from the lower ends of which the tubing is bent to form the forwardly extending legs I4 and I5 respectively. Across the upper sides of these legs I4 and I5 is mounted any suitable supporting structure herein shown as consisting of a pan I6 which is secured to the legs l4 and I5 preferably in a detachable manner, such as by the bolts I1. An axle I8 is carried across the undersides of the legs I4 and I5 close to the rear ends thereof. This axle I8 is fixed against rotation by means of the straps I9, one on each outer side respectively of each leg I4 and I5,

these straps l9 being connected directly to the pan I6. On the outer ends of the axle I8 are rotatably fixed wheels 29 respectively.

On each of the standards I2 and I3 adjacent the lower ends thereof is mounted an anti-fricti-on .shoe designated generally by the numeral 26 in each instance, the shoes being identical in construction .one to the other.

The'shoe 21 in each instance is formed out of sheet metal arched to form an upper portion '22 through which the leg I2 or I3 as the case may be, may slidin'gly extend. From each side of this arched portion- 22, the metal is carrieddownward- 1y or backwardly from the leg 3 for example, by a'wa'll 23' on the one side and 24 on the other. These walls 23 and 24 have inwardly turned legs 25 and 26 one extending toward the other in the same plane. From the inner end of the leg 25, the metal is turned back toward the standard 13;" Fig. 6, a short distance by a length 2'! then is-c'urved around in an arcuate manner toward the wall 23 to form the cupped length 28. In like manner the metal extends from the end of the leg 26 in contact with the length 21 by a portion 29 and then curves outwardly toward the wall 26 by a cupped length 30.

A number of through rivets 3 I, herein shown as four in number, are carried through the side walls 23 and 24 and also the cupped walls 28 and spaced from the legs 25 and 26 toward rail I3; Fig. 6, a distance to position those rivets 3| substantially centrally of the cupped portions 28 and 30.

These rivets 3i are employed to hold the Wall portions 21 and 29 in contact one with theother whereby a groove is formed and maintained between the cupped portions 28 and 3G to retain therein a number of balls 32, herein shown as three in number. The portions 28 and 30 are curved to follow generally the curvature of the balls 32, but terminate by their inner ends a distance from the rail I3 in order that the balls 32 may beheld by the contact with the rail I3 and the bottom of the groove at least by those members 28 and 30.

As indicated in Fig. 7, one ball 32 is spaced be tween each of the adjacent rivets 3I so that the permissible travel along the members 28 and 30 is limited by the respective balls 32 coming into contact with the rivets 3|. As indicated in the drawing, the length of the arch portion 22 is less than the lengths of the walls 23 and 24. This difference in lengths is provided in order to permit the shoe 2| 'to travel along the rail l3 (or rail I2) downwardly to have a considerable portion of the walls 23 and 24 below the junctures of the legs I4 and I5 with their standards I2 and I3, this degree of travel being indicated by comparison with the positions of the shoes 2! in Fig. 1 and Fig. 4.

members 28- and 30 in rolling The shoes 2| are normally positioned yieldingly in upper positions as indicated in Figs. 1 and 2. This elevation of the shoes 2| above the legs l4 and |-5 is determined in relation to the diameter of the wheels 2|) to have the back side of the shoe in each instance consisting of the leg portions 25 and 26 strike the outer corner of the tread of a stairway, Fig. 1, indicated by the dash line position. Then upon pulling the truck upwardly as indicated in Fig. 4, the shoes 2| will remain against the tread corner designated by the nuineral 33 by pressure thereagainst and the standards l2 and l3 will be contact over the balls to be finally rolled back on 32 to allow the wheels 20 the top of that tread pulled upwardly in rolling whose corner 33 is then contacted by the shoes 2|. Once the wheels 2!] are back on that tread, the shoes 2| are automatically returned to their uppermost positions.

The means for creating this automatic return of the shoes 2| consists of two opposed springs 34 and 35 carried within the walls 23 and 24. Spring 34 has its lower end engaged with the rail l3 and its upper end engaged with the upper portion of the wall 2 3, Fig. 7. The spring 35 has its upper end fixed to the rail l3 and its lower end fixed to the lower portion of the wall 23. Thus when the shoe 2| is relatively pulled downwardly along the standard It, the spring 35 is extended in length whereas the spring 34 is decreased in length so that upon release of the shoe 2| permitting it to be free to travel along the rail l3, the spring 35 will carry the shoe 2| upwardly until the pulls of the two springs 34 and 35 are substantially balanced. It is to be understood that both springs 34 and 35 are initially placed under tension by stretching them between their end engagements. The upper spring 34 is employed to limit the upward travel of the shoes 2| along the rail l3 so that it will be normally properly positioned for contact with the corner 33.

While I have herein shown and described my invention in the one particular form, it is obvious that structural changes may be employed without departing from the spirit of the inventionand I therefore do not desire to be limited to that precise form beyond the limitations which may be imposed by the following claims.

I claim:

1. A hand. truck comprising a wheel mounted frame having a pair of side rails normally up-- \vardly extending, and a shiftable shoe on each of said rails,'each shoe comprising a box-like member encircling the railto have a forward side slidably'engaging the rail and a rear or under bearing.

side, and a spring interconnecting said railand said member in a manner to increase the tension on the spring upon relative downward travel of the shoe along the rail, wherebythe spring will railand said member 4 tend to return the shoe to an upper normal position of rest.

2. A hand truck comprising a wheel mounted frame having a pair of side rails normally upwardly extending, and a shiftable shoe on each of said rails, each shoe comprising a box-like member encircling the rails to have a forward side slidably engaging the rail and a rear or under bearing side, and a spring interconnecting said in a manner to. increase the tension on the spring upon relative downward travel of the shoe along the rail, whereby the spring will tend to return the shoe to an upper normal position of rest; said member having a groove between the rail and said underside; and ball bearings in said groove, between it and the back side of said rail.

3. A hand truck comprising a wheel mounted frame having a pair of side rails normally upwardlyextending, and a shiftable shoe on each of said rails, each shoe comprising a-boX-likemember. encircling the rails to have a forward side slidably engaging the rail and a rear, or under bearing side, and a spring interconnecting said rail and said member in a manner to increase the tension on the spring upon relative downward travel of the shoe along the rail, whereby the spring will tend to return the shoe to an upper normal position of rest; said member having a groove between the rail and said underside; and ball bearings in said groove; between it and the back side of said rail; and a second spring interconnecting said rail and said member normally oppositely balancing the pull of said first spring.

4. A hand truck rail bearing shoe comprising a housing having an upper arched portion to slide along said rail, from the sides of which housing side walls extend; a floor between those walls; a ball bearing carrying grooved member mounted over the floor and between the wall; balls in said member; a coil spring fixed to said housing and extending internally thereof along one of said walls; said floor being formed in two parts, each part consisting of a leg inturned from the said walls one leg toward the other; and said groove member being formed by two arcuate parts, one part turned from one of said legs and the other part from the other leg.

JOHN C. GATES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Payso-n Sept.-'5, 1939

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