US2790649A - Wheeled base for office machines - Google Patents

Description

April 30, 1957 w. LUBBE 2,790,649

WHEELED BASE FOR OFFICE MACHINES Filed Dec. 15, 1954 United States Patent M WHEELED BASE FOR OFFICE MACHINES Walter Liibbe, Wilhelmshaven, Germany, assignor t0 Olympia Werke Aktiengesellschaft, Wilhelmshaven, Germany Application February 15, 1954, Serial No. 410,104

2 Claims. (Cl. 280--47.13)

In order to facilitate the displacement of oflice machines, for example computing machines, over a table surface or the like such machines are usually provided with supporting rollers consisting of elastic material, arranged under a base plate of the machine and adjacent the corners thereof. The base plate is secured to the machine housing at the lower side thereof. The elastic supporting rollers at the rear end of the machine are mounted on a shaft which is supported in the legs of a Ll-shaped holder member consisting of pressed sheet metal. Displacement of the machine over the table surface is accomplished with the front part of the machine slightly raised, the supporting rollers rolling on the table surface.

It is an object of the invention to divide the supporting rollers in their holders with regard to their length in such a manner that they permit a compensating rotation of the parts on their shafts in the holders, i. e. that the different lengths of travel of the supporting rollers which result when the machine is displaced along a curved path are compensated for by a difierential action.

In the novel holder construction according to the invention the supporting rollers are substantially arranged in such a manner that at least two rollers are rotatably supported on the shaft of each holder, thus each of the rollers being freely and independently rotatable on the common shaft. The individual rollers are conveniently separated from each other by spacer means which may consist of a spacer ring arranged on the shaft.

If the rollers are made very narrow or with little elasticity the arrangement of the Web parts of the U-shaped roller holders in recesses of the above mentioned base plate may, according to another feature of the invention, be made in such a manner that each holder web is nonrotatably located in the corresponding recess of the base plate by means of a locating pin engaging a bore in the base plate; or this location may be accomplished by the provision of corresponding abutment shoulders on the holder web and the recess.

The marginal zone around the hole, provided in the web portion of the holders for the passage of the mounting bolt, may be bent outwardly in the direction of the legs of the U-shaped holder to form a conical projection, against the inner diameter of which abuts the conical head of the mounting bolt. Centering is thus accomplished independently of the adjustment of the hole to the bolt diameter which would otherwise be necessary simply by the abutment of the conical bolt head (countersunk head screw) against the inner periphery of the bentout conical projection. In this case it is not required that the diameter of the hole be very accurate in relation to the bolt diameter. The bent-out conical portion also serves to stiifen the Web portion of the holder. These mounting means, together with the aforementioned locating pins and/or abutment shoulders, constitute the means for effecting a non-rotatable connection of the holder with the base plate of the machine.

Further details of the invention will be apparent from 2,790,649 Patented Apr. 30, 1957 the following description of an embodiment of the novel holder construction for supporting rollers on an oifice or computing machine which are given by way of example only, and are illustrated in the accompanying drawing in which:

Fig. 1 is a side elevation of an oflice or computing machine showing the arrangement of the supporting rollers at the rear end of the base plate of the machine;

Fig. 2 is a perspective view of a holder construction with supporting'rollers adapted for non-rotatable mounta;

Fig. 3 shows the component parts of the construction according to Fig. 2, and also the mounting bolt with coni cal head used with this holder construction;

Fig. 4 shows a base plate of a machine with two holders for supporting rollers in perspective representation;

Fig. 5 is a plan view of a corner of a machine base plate with a recess for the reception of a holder adapted to be non-rotatably secured by means of a locating pin and/ or abutment shoulders;

Fig. 6 is a sectional view taken along line VI-VI of Fig. 4 in connection with part of a machine housing including the base plate.

The office or computing machine A generally indicated in Fig. 1 has at its rear end under the base plate 7 supporting rollers 1 of elastic material which are supported in holders 2 of pressed-sheet metal. At' the front end the machine rests on rubber butters 2' in the usual manner. As may be seen from Figs. 2, 3, 4, and 6, the holders 2 comprise a plane web portion 2a from which extend two legs 2b which are so bent that they are situated opposite each other and form a U-shape together With the web portion 2a. The legs 2b of the U comprise bores 20 adapted to receive a shaft 3 which is located in axial direction in the leg portions 2b of the U-shaped holder 2 by means of securing member 4. In normal working position the shaft 3 is disposed in the holder 2 in parallel relation to the base plate 7 of the machine A. The narrow supporting rollers 1 are provided with rigid bearing bushes 1' consisting of metal. On each shaft 3 there are mounted two supporting rollers 1 which are rotatable freely independently of each other. They are separated by spacer means in the form of a spacer ring 5 slipped over the shaft 3 so as to be freely rotatable thereon. The legs 2b of the U-shaped holder 2 projecting from the plane web portion 2a form abutment shoulders. Conveniently, the Web portion 2a between the leg portions 2b is of circular shape over a substantial part of its circumference. As may be clearly seen from Figs. 2, 3, and 6 the marginal zone around the hole for the conical-head mounting bolt 6 (countersunk head bolt) is bent outwardly at 11 in a conical form, and in the direction of the legs 2b of the U. In the direction opposite to the bent-out portion 11 extends a locating pin 12. The web portion 2a of the holder 2 fits into a recess 13 formed by drawing in the base plate 7 secured to the machine housing 8 at the lower side thereof. Towards the edge of plate 7 the recess 13 terminates in two parallel abutment shoulders 14 as may be seen from Fig. 5. These shoulders 14 cooperate with the abutment shoulders, formed by the leg portions 2b of the U-shaped holder 2, so that the holder 2 is non-rotatably located when its web portion 2a is in serted into the recess 13. In addition to or instead of the abutment shoulders, a pin 12, engaging a bore 10 in the base plate 7, may be provided to prevent rotation of the holder 2 with respect to the base plate 7. The holder 2 is connected with the base plate 7 and the machine housing 8 by means of a threaded bolt 6, an elastic cushioning ring 9 being interposed between the base plate 7 and the machine housing 8, and the conical head on of the bolt 6 pressing against the free edge 11a of the conical bent-out portion 11. The bent-out portion 11 not only serves to effect the previously described centering, but also stiflens and reinforces the web portionla of' the holder 2. The mounting bymeans of a countersunk head screw 6 in the manner described and illustrated does not only present theadvantage that the size-of the hole in the bent-out portion 11 is independent from the diameter of the threaded bolt 6 within certain limits, but is also advantageous so far as exact centering of the base plate 7 is effected by the conical part of the countersunk head screw 6 when screws of different sizes are used in different machinesor various machine parts and, for reasons of economy, are also to be employed for the present purpose. The arrangement of the supporting rollers 1 in each holder 2, at a distance fromand rotatable independently of each other, practically eliminates any rubbing action of the elastic rollers when thelongitudinal axis of the machineA is directed tangentiallyto the path of movement of the machine, because the rollers I assume different rotational speeds, and are thus capable of compensating for the different lengths of their travel.

I claim:

1. A holder construction for supporting rollers of clastic material of an o'fiice' machine,:comprising in combination, a machine housing;.a base'plate secured to said housing at the lower side thereof; two U-shaped holders of pressed sheet metal arranged at the rear end under said base plate, each of said holders havinga web portion; two threaded conical-head mounting bolts, each of said bolts mounting one of said holders to said base plate; a shaft supported between the legs of each of said holders and extending parallel to said base plate; two rollers being supported on said shaft of each of said holders so as to be freely and independently rotatable thereon; spacer means, each arranged on said common shaft between said two rollers adapted to hold said rollers in spaced relationship; two recesses drawn in said base plate and each recess adapted to receive said 'web portion of a corresponding one of said holders; a hole provided in each of said web portions, the marginal zone around said hole being bent outwardly so as to form a conical projection, the conical part of each of said mounting bolts bearing against the edge of said projection.

2. The holder construction of claim 1, in which each of said recesses and each of said holders are provided with cooperating abutment shoulders.

References Cited in the file of this patent UNITED STATES PATENTS 150,132 Buckingham Apr. 28, 1874 785,601 Fischer Mar. 21, 1905 1,435,371 Bartlett et al Nov. 14, 1922 2,068,160 Zeindler Jan. 19, 1937 2,311,928 ,Buehler Feb. 23, 1943 2,424,032 Henderson July 15, 1947 2,502,929 Clark Apr. 4, 1950 2,529,475 Anneren Nov. 14, 1950 2,575,968 McCallum et al Nov. 20, 1951 FOREIGN PATENTS 220,780 Germany Apr. 8, 1910

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