GB2173093A

GB2173093A - Caster mounting apparatus

Info

Publication number: GB2173093A
Application number: GB08517637A
Authority: GB
Inventors: Elsmer W Kreeger
Original assignee: Pinckney Molded Plastics Inc
Current assignee: Pinckney Molded Plastics Inc
Priority date: 1985-04-05
Filing date: 1985-07-12
Publication date: 1986-10-08
Also published as: GB8517637D0

Abstract

Casters 14 are detachably mounted upon the underside of the frame 10 of a dolly by means of a single bolt 36. The caster is provided with a flat, horizontally disposed mounting plate 22 which underlies and bears against a horizontal surface defined by the lower edges of ribs 17 and surrounded by a wall 18 on the bottom of the frame. The mounting plate can be vertically moved into face-to-face engagement with the horizontal surface when in a first angular orientation and then rotated about a vertical axis to a second angular orientation in which webs 30, 32, 34 spaced below the horizontal surface underlie portions of the plate 22 to retain it against vertical separation from the frame. A single bolt detachably retains the plate against rotation from this last position. <IMAGE>

Description

SPECIFICATION Caster mounting apparatus The present invention is concerned with apparatus for detachably mounting casters upon dollys or other load-carrying apparatus.

Conventionally, dollys ofthe type employed by furniture movers consist of a rigid, load-supporting frame having casters whose mounting plates are fixedly secured to the underside ofthe frame by bolts or lag screws. The casters are the most vulnerable part of the dolly and require frequent replacement. In the usual case, this involves the removal of typically four or more bolts or lag screws in order to remove the faulty caster and the replacement of the same number of bolts or screws to mount the new caster.

This particular type of caster mounting relies upon the tightness of the bolts or screws to hold the caster in a fixed position relative to the frame. The shock loadings encountered by the caster in normal usage tend to progressively loosen the coupling between the caster and the frame, and the looserthis coupling becomes, the more vulnerable the caster becomesto damage.

The present invention is directed to an arrangement by which a caster may be positively retained in position upon a dolly frame by means of a single bolt which is in turn subjected to a minimal amountof loading during operation.

In accordance with the present invention, the underside of theframe of a dolly or other loadsupporting frame is formed on its bottom surface with a downwardly facing, horizontal, plate-engaging surface which may be defined by the lower edges of ribs formed on the underside of the frame. The plateengaging surface has a continuous peripheral sidewall extending around the periphery ofthe surface and projecting downwardly from the surface. The configuration ofthis peripheral sidewall is such that it will accommodate, for limited rotation about a vertical axis, a generally rectangular mounting plate of a caster, the caster mounting plate having a horizontal upper surface adapted to be disposed in face-to-face engagement with the plate-engaging surface on the frame.The configuration ofthe sidewall is such that when the mounting plate is located in a first orientation about a vertical axis relative to the frame, it may be moved vertically into engagement with the plateengaging surface within the periphery ofthe sidewalls. When so engaged,theconfiguration ofthe sidewalls is such that the mounting plate may be rotated about a vertical axis to a second angular orientation relative to the frame. Horizontal webs are fixedly mounted on the sidewalls at selected locations along its periphery and are arranged so that, when the plate is in the second angular orientation referred to above, the webs underlie portions of the mounting plate, extending generally across three corners of the generally rectangular plate, to retain the plate against vertical separation from the plate-engaging surface on the frame.When in this last position, a single retaining bolt is employed to hold the plate against rotation aboutthevertical axis relative to the frame.

Thus, as long as the plate is held against rotation relative to the frame, it is trapped bythewebs and plate engaging surface against any vertical movement relative to theframe. The retaining bolt is required to resist only relative rotary movement of the plate relative to the frame.

Other objects and features ofthe invention will become apparentfrom the following specification and accompanying drawings.

FIG. is a bottom view of a dolly frame constructed in accordance with the present invention; FIG. 2 is a detailed cross-sectional view taken on line 2-2OfFIG.1; FIG .3 is a perspective view of one corner of the frame, showing the mounting plate of a dolly in its assembled relationship with the frame; and FIG. 4 is a perspective view of a caster provided with a mounting plate embodying the present invention.

Referring first to FIG. 1, there is shown a bottom view of a generally rectangular dolly frame designated generally 10 which in the particular example shown may be injection moulded from a suitable plastic material and formed with suitably arranged stiffening ribs, such as 12. Atthe lower right-hand corner of the frame 10, as viewed in FIG. 1, there is shown a caster assembly designated generally 14 assembled to the frame. Casters 14 are intended to be mounted atthe remaining corners of frame 10, but are not shown in FIG. 1.The mounting structure for mounting casters to frame loins the same at each corner of the frame, and the structure ofthe frame which forms the mounting means is bestseen from FIGS. 1,2 and 3.

At each corner of frame 10, the bottom ofthe frame is formed with a horizontal plate-engaging surface 16 defined bythe lower edges of ribs 17. Adownwardly projecting sidewall 18 extends around the entire periphery of each plate-engaging surface 16. The peripheral configuration of sidewall 18, as viewed in FIG. 1, must be conformed in a particular mannerto the mounting plate of a caster, for reasons which will become apparent. Referring to FIG. 4, there is shown a casterassembly20which includesagenerallyrec- tangular mounting plate 22 having a flat, horizontal upper surface 24. A swivel caster wheel designated generally 26 is mounted in a conventional manner to mounting plate 22.A relatively short, diagonally extending slot 28 is cut through the plate adjacent one corner.

Returning now particularlyto FIG. 1, see also FIG. 3, the peripheral configuration of sidewall 18 is such that if theflatuppersurface24Ofcastermounting plate 22 is placed in face-to-face engagement with the plate engaging surface 16 on the dollyframe, the plate may be rotated about a vertical axis between a position wherein its side edges extend parallel to the side edges of frame 10 and a second position wherein the side edges of plate 22 are inclined or nonparallel to the side edges offrame 10. Engagement of a side edge of mounting plate 22 with section 1 8a of sidewall 18 establishes the last-mentioned angular relationship of plate 22 relativetoframe 10,whileengagementofthe opposite side edge of plate 22 with a section 1 8b of sidewall l8establishesthatangularorientation of plate 22 relative to frame 10 where its edges extend parallel to the sides of the dolly frame.

Fixedly secured to sidewalls 18 are three horizontal webs 30,32 and 34 which project inwardly from the peripheral sidewall 18 to overlie portions of the plate-engaging surface 16. As bestseen in the cross-sectional view of FIG. 2, the webs 30,32 and 34 are horizontally spaced from the plate-engaging surface 16 by a distance which is equal to orslightly greaterthan the thickness of mounting plate 22 ofthe caster. The inner edges 30a, 32a and 34a are, as best seen in FIG. 1,so located and orientedthata caster mounting plate 22 may be vertically moved into face-to-face engagement with plate-engaging surface 16 ofthe frame ifthe plate is oriented atthe given angle relative to the sides offrame 10.When the flat surface 24 of plate 22 is so moved into engagement with surface 16, the plate may then be rotated about a vertical axis to the frame to move three corners ofthe plate into respective underlying engagement (see FIG.

2) with webs 30,32 and 34when the plate is rotated to the second angular orientation wherein its sides extend parallel to those offrame 10.

It is believed apparent that when so located, the webs 30,32 and 34will retainthe plate against vertical separation from the plate-engaging surface 16, and the plate will remain assembled with frame 10 as long as it is in this last rotative orientation relative to frame 10.

To retain the plate in this last-mentioned orientation, a nut-and-bolt assembly designated generally 36 passes through a suitable opening 38 (FIG. 2) in frame 10 and through the slot 28 in mounting plate 22.

While one embodiment of the invention has been described in detail, itwill be apparent to those skilled in the artthe disclosed embodiment may be modified.

Therefore, the foregoing description is to be consi dered exemplary ratherthan limiting, and the true scope of the invention is that defined in the following

Claims

claims. CLAIMS

1. In a dolly or the like comprising a horizontally disposed, load-supporting frame, a plurality of casters supporting said frame, and means detachably mounting said casters upon the underside of said frame, said casters each including a mounting plate having an uppersurfacelying in a horizontal general plane;; the improvementwherein said mounting means comprises means on the bottom of said piane adjacent each corner thereof defining a flat, horizontal, mounting plate-engaging surface, a peripheral sidewall extending around each of said plate-engaging surfaces and projecting downwardlyfrom said surface, said peripheral sidewall being conformed to surround the periphery of said mounting plate when said upper surface of said mounting plate is located with its upper surface in face-to4ace engagement with said plate-engaging surface and to accommodate limited rotation of said plate relative to said frame, while so engaged, about a vertical axis between first and second angular positions relative to said frame, a plurality of horizontally disposed webs fixedly se cured to said sidewall atspaced locations thereon and underlying respective portions of said plate-engaging surface and spaced from said plate-engaging surface by a distance at least equal to the thickness of said mounting plate, said webs being conformed to accommodate vertical movement of said plate into face-to-face relationship with said plate-engaging surface when said plate is in said first angular position relative to said frame and to underlie and retain said plate in face-to-face relationship with said plateengaging surface when said plate is located in said second angular position, and releasable meansfor maintaining said plate against rotation from said second angular position.

2. The invention defined in claim 1 wherein the periphery of said plate is of general rectangular configuration, said webs underlying at least two opposed corners of said plate when said plate is in said second angular position.

3. The invention defined in claim 1 wherein the periphery of said plate is of generally reactangular configuration, said webs underlying three corners of said plate when said plate is in said second angular position, and wherein said releasable means comprises means defining an opening through said plate adjacentthe remaining cornerofsaid plate,and bolt means mounted in said frame and passing through said opening.

4. Apparatus for detachably mounting casters upon dollysorotherload-carrying apparatus, substantially as herein before described with reference to the accompanying drawings.