Note: Descriptions are shown in the official language in which they were submitted.
1077~()9
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BACKGROUND OF THE INVENTION
Prior casters have Drovidea arrangements where
a suppcrting wheel, or floor engaging element is rota-
tably mounted on an inclined axle offset from a vertical
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pivot axle about which the caster swivels. In such designs
the caster consisted of a pair of complemental hemis-
pherical, opposed casting sections to form a generally
; enclosed hollow shell wherein one of the casting sections
was relativel~ fixed on the vertical pivot and the other
casting section constituted the rotatable wheel, or
floor engaging roller. Tilted axle casters of this
general type permit the hollow shell to swivel about the
vertical axle. However, the enclosing sections have always
been made up of castings and while they have been made from
die castings they necessarily were relatively heavy and con-
sequently costlY, both from the stand~oint of the casting pro-
cesses involved and the necessity for sufficient strength in
the completed caster to support the relatively heavy loads
which the casters were adapted to carry. The amount of
material in such casters has become burdensome from a cost
standpoint with the constantly increasing cost of materials
... . .
and as a consequence competitive advantases of casters
of superior design are on the verge of being lost to compe-
:`
; titive casters and particularly with the advent of the
expiration of basic U.S. patents, from foreign competi-
tion where oroducers are able, with lower labor and
material costs to furnish a proven caster structure
from an expired U.S. patent and thus provide ~ sood caster of
1~7~0~?
fully developed design without having any of the development
costs ordinarily entailed in the production of a caster
of competitive quality. Such cas~ers can be sold ~or less
than the price of a domestic product which has been developed
and produced on the basis of all normal costs included in
the marketing price of the caster. Consequently, it has
become necessary to reduce the costs involved in producing
a caster of new and improved design and representing a suitable
structure able to compete on the basis of price as well as
quality.
According to the present invention there is provided
a caster assembly having two basic parts including a body
frame and a separate wheel rotatable relative to the body
frame, the body frame having a vertical swivel tube rigidly
associated with the body frame. A canted axle is fixedly
mounted on the body frame, and a thin gauge hollow shell
encloses one side of the body frame and the swivel tube.
The shell extends over the peripheral edge of the body frame
at least in part to secure the shell to the body frame. The
wheel is rotatably mounted on the axle and has a tread
portion overlying the shell extending over the peripheral
edge of the body frame. A thin gauge hollow shell encloses
the open side of the wheel and is secured to a rim portion
of the wheel.
The present invention provides a caster wherein
the manufacturing costs can be reduced both by taking weight
and material out of the structure and by providing an
enclosed axle tilted wheel caster design capable of efficient
manufacture. This has been accomplished primarily by re-
designing the caster structure to provide basically twooperating parts comprising a circular like body frame in the
form of a dished or flat, corrugated or ribbed member carrying
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a provision for swiveling and an axle and a separate wheel
for rotation on the axle. The body frame and the wheel can
each be enclosed by a cover, of lightweight construction,
secured thereto and which in the assembled caster gives the
completed assembly a generally attractive form. An important
improvement in the new design is realized from the fabrication
of the body frame and the wheel from lightweight metal
stampings or mouldings and the fabrication of the enclosing
covers from thin gauge metal such as aluminum, steel, or
plastic, whereby further to lighten the weight of the caster
assembly. These parts can be made from other materials which
may be suitable for the purpose. Presently it has been found
that the metal stampings lend the desired effect most readily,
giving the caster assembly the desired strength while re-
ducing the weight of the material used and thereby the cost
; and are easily fabricated. A lightweight version of the
j
;, invention with at least certain of the parts fabricated
from precision castings, affords realization of certain ad-
vantages of the inventive concept and incorporates basic
principles thereof by the inclusion of a cast body frame
carrying the swivel and the axle and having a wheel of
fabricated or cast design rotatably mounted on the axle.
Thin gauge metal covers of lightweight and any desired shape
are secured on the body frame and wheel respectively to
give an overall generally enclosed form to the caster assembly.
The primary purpose of the invention is to provide
a caster of low cost design, having lightweight, fabricated
from parts affording required strength properties and having
enclosing covers which give the caster assembly an overall
generally enclosed form.
DESCRIPTION OF THE DRAWINGS
The foregoing and other and more specific objects
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of the invention are attained by the structure and arrangement
of the caster assembly illustrated in the accompanying
drawings wherein
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Figure 1 is a general perspective view of a fully
assembled caster according to this invention;
Figure 2 is a sectional view of the caster assembly
showing the body frame with attached swivel stem parts, the
axle mounted wheel and the covers secured to both;
Figure 3 is a sectional view of the caster taken on
the line 3-3 of Figure 2;
- Figures4 and 5 are detail horizontal sectional views
taken on the lines 4-4 and 5-5 respectively of Figure 3;
Figure 6 is a sectional view through a caster of
modified form;
Figure 7 is a general vertical sectional view taken
on the line 7-7 of Figure 6
~ Figure 8 is a detail horizontal view taken on the
.~ line 8-8 of Figure 7;
. Figure 9 is a detail view of the swivel tube structure
: of the type used with the caster of Figure 6;
Figure 10 illustrates a modified form of body frame
with integrally attached swivel tubei
Figure 11 is an elevational view of the body frame
from the plane 11-11 of Figure 10;
Figure 12 is a horizontal detail sectional view
taken on the line 12-12 of Figure 11 showing the integral
structure of the swivel tube with the body frame;
Figure 13 is a detail hori~ontal sectional view
taken on the line 13-13 of Figure lli
Figure 14 is a perspective view of the body frame
. and integral swivel tube of Figures 10 and 11;
. Figure 15 is a generally vertical sectional view
.~ 30 of a further modified form of the.invention where the body
frame and swivel structure as well as the axle mounted wheel
are constructed from precision castings and each with
. a separately attached cover;
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Figure 16 is a sectional view taken on the line
16-16 of Figure 15;
Figure 17 is a detail view of the cast body frame;
Figure 18 is an elevational view of the body frame
showing the opposite face thereof from that shown in Figure 16;
Figure 19 is a general cross sectional view of
a fully assembled caster having a body frame member
which comprises a centrally dished, generally circular
plate and a wheel fabricated from two parts including
a rim and an enclosed hub;
Figure 20 is an elevational view of the generally
circular dished plate body member having an integrally
formed swivel tube shown from the side facing the wheel;
Figure 21 also is an elevational view of the
dished plate viewed from an edge of plate and showing the
. . angularity of the swivel tube relative to the plate and an
enclosed socket for a fixed axle;
Figure 22 is a top view of the dished plate, enclosed
axle socket and swivel tube;
Figure 23 is an elevational view similar to Figure
20 showing a modified form of the body frame member having
; a separately formed swivel tube rigidly secured to the
circular plate;
Figure 24 is a top view of the body frame and
swivel tube structure shown in Figure 23;
Figure 25 is a view similar to Figure 21 showing
an edge view of the dished plate and swivel.tube structure
illustrated in Figures 23 and 24;
Figure 26 is a general sectional view of another
~ 30 , form of the invention utilizing a precision cast body frame
: member;
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Figure 27 is an elevational view, ~artly in section,
taken on the line 27-27 of Figure 26 showing the skeleton-
ized structure of the body frame member and integral swiveL
tube;
Figure 28 is an edge view of the body frame member
illustrated in Figure 27 showing the integral swivel tube
and an integral socket for a fixed axle;
Figure 29 is a top view of the precision cast body
frame member of Figures 26, 27 and 28;
Figure 30 i5 a front elevational view of the two
part wheel structure with the decorative cover removed
showing the rim member and the enclosed hub member; and
Figure 31 is a cross sectional view through a
wheel assembly having an outwardly projecting annular
flange, or inner rim mem~er, for the attachment of a re-
movable plastic cover.
DESCRIPTION OF FIRST E~qBODI~IENT
In the drawings, as shown in Figures 1 through 5,
a generally enclosed form of caster assembly 10 is shown as
being comprised of stamped metal parts including a body
frame 11 which,in this form, is of a generally flat, or pan-
cake-like configuration, a rotata~le wheel 12 and light
- weight metal covers 13 and 14 secured on the body frame and
wheel respectively. These covers, as shown here, are secured
to the body plate and wheel by crimping the edge of the
respective covers over the edge of the body frame, as at
15, and over the edge of the wheel, as at 16. The-body frame
- 11 is disc-like with a centrally disposed inwardly turned
; collar, or boss 17, in which an axle member 18 is fixedly
mounted. The body frame 11 is disposed at an angle to the
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vertical and the axle 18 is perpendicular thereto so that the
axle is canted, as best shown in Figure 2.
The wheel 12 turns on the axle in this position and
rotates in a olane perpendicular thereto but the tread 19 of
the wheel and the overlying cover portion, is shaped and dis-
posed to engage a supoorting surface, or floor, in a normally
rolling flatwise engagement. The axle 18 is prevented from
turning in the boss 17 by a press fit, knurling, or serrations
20 engaging the inner periphery of the boss and is provided
with an inner head 21 ~Ihich positions the axle in the boss
17. The wheel 12 is held on the axle by a washer 22 which may
be of a suitable plastic, or metal bearing material and a lock
washer 23. Ihe wheel 12 is provided with a central bearing
24 within the central ~ournal 25 and this bearing also is of
a suitable plastic, or metal bearing material, as is the thrust
bearing washer 26 at the inner side of the wheel bearing against
the body frame 11.
The body frame 11 mounts a swivel stem structure on
a vertical axis and in this form of the invention the swivel
tube structure 27 is secured to the body frame 11 as a separ-
ately formed element comprised of a support bracket 28 and
the swivel tube 29, which is adapted to receive the stem 30
for the caster. The support bracket 28 includes a generally
tubular socket 31 for the swivel tube 29 and flat portion
;~ 32. The flat portion is of double thickness and the socket
31 is formed integrally by wrapping the bracket around a suit-
able shape, or die, to form the socket. The socket is formed
with a tapered portion 33 which conforms with a similarly
tapered portion on the ~ube 29. The swivel tube 29 extends
through the socket 31, as best shown in Figures 2 and 3, and
seats on a shelf 34 formed integrally with the frame 11. The
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shelf 34 is formed with an uostanding embossment 35 about
which the tube 29 fits and is seated. The flat portions of
the support bracket are formed with an inwardly directed collar
structure 36 adapted to fit over the central collar 17 on
the body frame 11, which serves to position and rigidify
the bracket on the body frame.
It will be noted that the tubular socket and swivel
tube portions of the support bracket are disposed at least
partially upon both sides of the plane of the body frame,
forwhich purpose the body frame is provided with cut-out
area 37 so that the socket 31 and tub2 29 can extend through
the body frame 11 at an angle corresponding to the inclination
of the body frame from the vertical. The flat portion 32
of the ~racket structure 28 is disposed in contiguous rela-
tion to the adjoining surface of the body frame 11 and is
rigidly secured thereto by clamping brackets 38, struck out
of the bracket extension 32 to hold the bracket 28 in tight
engagement with the body frame. This attachment together
with the collar structure 36 engaged around the body frame
central collar 17 securely positions and maintains the
fixed relationship of the entire bracket structure with the
body frame. If desired, the bracket structure 17 can be
integrated with the body frame by welding, brazing or riveting.
The body frame 11 and thewheel 12 are both formed
from metal of similar thickness while the enclosing covers
13 and 14 are formed from thin gauge light weight metal such
as aluminum, thin gauge steel, or the like. The body frame
and wheel must be of sufficient strength to suDport the loads
imposed but the covers are not subjected to any undue stress
and therefore can be applied as purely ornamental. The cover
~ 13 is perforated, as at 39, for passage of the tube 29 there-
~Q77Z09
through, as best shown in Figure 1. The cover 14 is closely
conformed to the tread 19 of the wheel 12, as best shown in
Figure 2, but since this area of the cover is immediately
backed up by the wheel tread 19 no undue forces are required
to be supported by the cover. The tread 19 of the wheel 19
and the central journal 25, which forms the hub of the wheel,
are integrally connected by web plate 40 which is disposed
generally in the outer plane of the wheel and is connected
with the central hub portion 25 at the inner side of the wheel
by a sloping web portion ~1. The tread 19, central hub 25
, and intervening web portions 40 and 41 are formed during
a stamping operation. The web of the wheel may be reinforced,
or stiffened, at regularly spaced intervals around the wheel
by means of corrugations 43, if desired or considered
necessary.
! The stem 30 is secured to a mounting plate 42
which secures the caster on an item of furniture, or the like.
The stem 30 swivels in the tube 29 and may be secured therein
against inadvertent withdrawal in any suitable manner, as
desired. The tube 29 is rigid with the socket 31 and may
be integrally secured thereto by welding, brazing or in any
preferred manner.
MODIFIED FO~ OF THE INVENTION
.
In the form of the invention illustrated in Figures
6 through 9, the body frame 11 and wheel 12 are fabricated
from metal stampings, as before, and the support bracket
j structure 27 is also separately formed and secured to the face
i of the body frame. The thin gauge light weight enclosing covers
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¦ 13 and 14 are secured to the body frame and wheel respectively,
in similar manner, with the cover 13 crimped over the edge of
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the body frame, as at 15 and the cover 14 crimped over the
edge of the wheel, as at 16. The body frame 11 is disposed
at an angle to the vertical and the axle 18 therefore is
canted and disposes the wheel 1~ for rotation in a plane
parallel to the body frame. The body frame in this form also
is flat and disc-li];e and is provided with an inwardly
directed central collar 17, through which the axle 18 extends.
The axle is fixed in the collar 17 by serrations, or a press
fit as at 20, so that it cannot rotate relative to the collar
and is provided with a head 21 which fixes the position of
the axle in the collar 17.
The support bracket structure 27 is formed with a
flat plate portion 45, having a central collar 45 extending
inwardly therefrom and surrounding the central collar 17
projecting inwardly from the body frame 11. The flat plate
portion 45 is disposed in surface engagement with the face
of the body frame and can be rigidly secured thereto, as by
welds 47, or by other means, if preferred. The relative
' position of the plate portion 45 on the face of the body frame
is fixed by a shoulder piece 48 struck out of the body frame
11 and projecting into a recess 49 in an edge plate 45. The
plate 45 is provided with a socket structure 50 integral
therewith and which is disposed vertically so that it is dis-
posed at an angle to the integral plate portion 45. A sloping
plate portion 51 connects the socket 50 with the flat plate
at the angle defined by the vertical disposition of the socket
and the angled position of the plate 45 on the body frame.
The tubular socket 50 is seated on a shoulder 52
formed integral with and bent from the body frame 11 to a
horizontal position underlying the bottom end of the socket
(see Figure 6). The socket may be secured to the shelf
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lQ772~g
formed by the shoulder 52 by welding or brazing, if de~ired.
As in the previous form of the invention ~he tubular socket
50 extends at least partially through the bod~ frame 11 at
an angle corresponding with the canted position of the body
frame from the vertical. The socket 50, as described, is
integral with the sloping plate portion 51 and the flat
plate portion 45 and is formed by rolling the metal about
a suitable form, or die, or the proper diameter and having
thetapered area 53 in the final form of the tuhe. The
upper end of the tubular socket 50 is provided with a
separately formed collar peice 54 secured thereto, as by
welding, or brazing. The caster stem 30 fits into the socket
through the collar piece 54 and the mounting plate, or bracket
42, is secured to the stem. As in the previous form, the body
frame 11 is provided with a cut-out area 37 for the passage of
the tubular socket 50, whereby the socket structure can be
disposed in a position extending upon opposite sides of the
body frame.
The wheel 12 rotates on the axle 18 and includes
a central hub 55 extending inwardly from a web portion 56
disposed in the outer plane of the wheel and which integrally
connects the hub with the tread portion 19 of the wheel. The
hub 55 is fitted with an internal bushing of plastic, bronze,
sintered metal, or other suitable bearing material 24 and a
thrust bearing washer 26 of similar material is disposed at
the inner side of the wheel between the bearing areas of the
inner end of the hub 55 and adjacent surface of the body frame
11. A washer 22, of suitable bearing material, is disposed on
the axle at the outer face of the wheel and secured by a lock-
ing washer 23. Stiffening corrugations 57 may be formed in
the web 56 of the wheel at regularly spaced intervals around
the wheel, if desired.
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107'7Z09
FURTHER MODIFIED FORM OF THE INVENTION
A concept illustrated in Figures 10 through 14 is
directed to a modification in the design of the body plate 11
wherein the flat disc-like plate and associated swivel tube
structure are of one piece construction with the swivel socket
: integral with the body frame. As shown in Figure 10, the in-
tegrally formed swivel socket 60 is disposed vertically and
the body plate 61 occupies a position at an angle to the socket.
. As best shown in Figure 11, the body frame 61 lS cut out, as
at 62, where the swivel socket 60 is formed and it will be
seen that the swivel socket is formed by wrapping the metal in
this area around a suitable die, or the like, to form the
tubular section comprising the swivel socket, which is best
:! illustrated in Figures 12 and 13.
PRECISION CAST VERSION OF THE INVENTION
The basic concept of the invention is followed in the
caster arrangement shown in Figures 15 through 18, but the
various caster parts take the form of precision castings
in this design, although the enclosing covers giving the caster
assembly its form continue as thin gauge, light weight
aluminum, or steel shapes that are crimped, or snapped into
place. The body frame casting 68 is canted at an angle to
the vertical and the integrally cast swivel socket 69 is dis-
posed vertically, with portions thereof disposed upon opposite
sides of the sloping plane of the body frame 68, as best
. indicated in Figures 15 and 18. An integral gusset 70
.`~ rigidifies and supports the bottom end area of the socket
69 where it is joined with the body frame 68 and as shown
in Figures 15, 16 and 18, this cast socket member 69 is also
.~ ~
provided with the tapered section 71. The upper end of the
swivel socket is provided with an encircling collar 72 and
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m77~0s
the stem 30, pro jecting downwardly from the mounting plate
42 for the caster, is entered into the socket 69 through
this collar.
Lntegrallv cast central collar 73 extends inwardly
from the body frame 68 and provides a bearing for the canted
axle 18 extending therethrough, with the head 21 on the axle
acting as a stop against the inner end of the collar 73
to position the axle relative to the body frame and having
serrations 20 on the axle to prevent its relative rotation
in the collar. The cast wheel 74 rotates on the canted axle
and therefore runs in an angular plane relative to the
vertical, as dictated by the angle of the axle 18. The wheel
is cast as one piece and includes a central hub with an
integrally cast peripheral tread 77 which is formed to
provide a supporting surface on the caster running sub-
stantially flatwise relative to a supporting surface,
or floor. The web 76 is disposed midway of the width of
tread 77, as shown in Figure 15.
A central bearing 24 is mounted in the hub 75
and is made from a suitable plastic, bronze, or sintered
metal material which affords a reduced friction running
surface on the axle. A thrust bearing washer 26 is disposed
.
between the inner face of the central hub 75 and the
adjoining face of the body frame 68 and this thrust
bearing is also made from a suitable bearing material
affording a reduced frictional engagement between the wheel
and the body frame. Washer 22 at the outer side of the
wheel 74 is made from a similar material and a lock
washer 23 secures the assembly and holds the wheel on the
axle. The thin gauge light weight aluminum, or steel
cover 78 on the wheel, fits into the inner periphery of the
tread 77 and is adapted to be pressed, or snapped intb
1077Z09
place, but the cover 13 is crimped over the edge of the body
frame 68, as at 15, similarly to the manner of securing
this cover on the other forms of casters hereinbefore
described. An opening 79 in the cover 13 provides for
the projection of the swivel socket 69 through the cover
to receive the stem 30 for mounting the caster on an
item of furniture, or other equipment, by means of the
mounting plate 42.
PREFERRED EMBODIMENT OF THE INVENTION
This embodiment of the invention incorporates
a dished body frame member of generally circular plate-
like form and a wheel member fabricated from separate
parts secured together to form a rigid assembly. The
generally circular body member comprises a dished plate
80 which is dished axially, as at 81, from the outer
perimeter toward the center of the circular plate, as
best revealed in Figures 20, 21 and 22. The dished portion
81 merges into a centrally disposed closed socket 82,
which fixedly mounts cne end of an axle 83 pressed into
the socket and fixed against rotation.
The dished circular plate body member incor-
porates an integral swivel tube 84 to receive a stem ~5,
; by means of which tne caster is swivelly mounted on an
article to be supported by one or more of such casters. A
bottom plate portion 86 extends under the lower end of
the swivel tube 84 to act as a limit stop, or support, for
the stem 85. The swivel tube includes a tapered portion
87 intermediate its top and bottom ends, which conforms
; with a similarl~ formed shoulder on the stem 85 to provide
an effective supporting bearing between the stem and
swivel tube. At its top end the swivel tube is formed with
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107 7ZOg
a reinforcing collar 88 and the caster 85 extends into
the swivel tube through this rigidifying top collar portion.
The integral swivel tube as in previous forms
of integral construction, is constructed by forming, or
rolling the metal about a suitable die of the proper
diameter, incorporating the tapered shape for the bearing
portion 87, whereby the integral tube is shaped and dis-
posed at the proper angle relative to ~he body plate 80
such that, in the operative position of the caster, the
swivel tube 84 and mounting stem 85 are disposed vertically.
The swivel socket being operable about a vertical
axis in operation and disposed at an angle to the body plate
80, disposes the body plate 80 in a canted position with the
axle 83 projecting outwardly at an angle to the horizontal,
having its axis at ninety degrees (90) relative to the
canted plane of the body plate.
The axle 83 is fixedly secured in the mounting socket
82 by a pressed fit, or it may include serrations so that, in
either event, it is prevented from rotating in the socket
relative to the body plate 80. Because of the canted position
of the body plate the swivel tube structure 84 is disposed upon
opposite sides of a plane represented by the face of the body
plate so that the swivel tube extends at least partially throu~-h
the body plate with its bottom end projecting beyond the ou~er
plane of the plate and its-upper end~disposed at the inner side
of the body plate.
i
The axis 83 rotatively supports a wheel assembly
~j .
90, which is of similar construction in the several forms of
the invention hereinafter to be described. The wheel assembly
includes two separately formed members 91 and 92 comprising
~ a rim member and an outer hub member respectively. The
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member 91 has an outer annular rim 93 formed integrally
with a central web 94 which is offset at 9S to dispose that
~ortion 94a of the web structure adjacent to the periphery of
the wheel in a plane spaced outwardly from the plane of the
central web portion 94 so that the rim 93 is generally centered
over the central web 94. The central web 94 is formed with a
flanged annular collar 96 comprising an inner hub for the
wheel which cooperates in.the mounting of the wheel assembly
on the axle 83.
The wheel member 92 has a web structure 97 disposed
in face-to-face engagement with the web 94 and rigidly secured
thereto by welding, as indicated at 98 in Figure 30. The web
97 is flanged outwardly about its ?eriphery, as at 99 and this
outwardly extending annular flange underlies the outwardly
offset 95 in the web 94. ~eb portion 97 merges with an
outwardly extending hub 100, integrally formed with the web
97 and which is disposed coaxially with the inner hub 96.
The outer end of the hub 100 is closed as at 101 so that the
end of the axle 83 is fully enclosed by the hub structure.
A bearing sleeve 102 extends into the combined hub structure
. 96 and 100.
,1
The outer hub 100 has an inside diameter which is
somewhat less than the inside diameter of the inner huh 96
so that the bearing sleeve has an outside diameter 103 where it
fits into the outer hub 100 and an outside diameter 104 where
it fits in the inner hub 96. The bearing sleeve has a cored
, out recess 106 in its inner surface located in the area of
i the change in outside diameters 103 and 104 of the sleeve. At
j its inner end an outwardly extending flange 105 on the bearing
sleeve 102 overlies the inner end of the hub 96 while the inner
end of the sleeve terminates in the outer hub 100 short of the
-- end of the axle 83.
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1077209
The axle 83 is assembled into the hub structure
96/100 of the wheel assembly 90 ~rior to the mounting of the
axle in the body frame socket 82. The axle has a head 107 and
as referred to above the bearing sleeve 102 at its inner end
stops short of the shoulder formed by the axle head. The sleeve
102 is mounted on the axle 83 and the assembled axle and
bearing sleeve are inserted into the hub structure 96/100
with the axle head 107 bearing against the inner face of the
hub end closure 101 and the outstanding flange lOS overlying
the inner end of the inner hub 96. The sleeve thus is
disposed between the hub structure and the axle where it
.; provides a bearing surface for the rotation of the t~heel 90
on the axle 83. ~ith the wheel and bearing sleeve mounted
thereon, the axle 83 is then pressed into the socket 82 of
. the dished body member 80 and the en~agement between the axle
head 107 and the end closure 101 serves to facilitate the
driving of the wheel and axle assembly into operative engage-
ment with the socket. Thus, with the axle fixed against
rotation in the body frame socket 82 the wheel will rotate
; 20 on the axle with the sleeve 102 forming a bearing between
the wheel hub structure and the axle.
~ MODIFIED BO Y FRAME MEMBER
: Figures 23, 24 and 25 illustrate a modified con-
. struction of the generally circular dished body frame plate
80 wherein the circular plate is of generally similar con-
struction to that described in Figures 19-22 with the plate
-. 80 being axially dished, as at 81., from the outer perimeter
:~ portions of the plate inwardly toward the center where it
.merges with the axle socket 82 having the enclosed end 101.
It should be pointed out that ~he axle socket 82 might be
- formed integrally with the dished plate 80, either in the
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107'7~09
form of the plate shown in Figures 19-22, or in the form
of Figures 23-25.
The body frame member 80 of Figures 23-25 differs
from the construction of this generally circular plate member
as shown in Figures 19-22 in that a separate swivel tube
member is provided that is rigidly secured to the body plate,
preferably by welding. This body plate 80 cut away in the
area of the swivel tube and is provided with an integral
flange 110 that extends vertically in the operative position
of the caster so that the body plate member 80 is canted in
relation thereto (see Figure 25). This flange is provided
for the attachment of a separate swivel tube structure 111,
also disposed vertically and disposed at an angle to the
body plate member corresponding with the relative angle of
the flange 110 so that the generally circular body plate
member 80 is canted relative to the swivel tube 111 in a
manner similar to the previously described form of the body
plate structure.
The separately formed swivel tube structure 111 is
provided with a pair of integrally formed, vertically
extending spaced apart flanges 112 which straddle the flange
110 on the body plate and afford a means of securing the swivel
tube to the body plate 80. The flanges 112 sandwiched over
the flange 110 are secured thereto as by welds 113 as best
indicated in Figures 23 and 24. The swivel tu~e 111 is provided
with a top reinforcing collar 114 surrounding the top end of
the tube through which a mounting stem 116 is inserted and an
intermediate tapered portion 115 affords an internal bearing
seat for the stem. The body plate 80 at the position where
it underlies the bottom end of the swivel tube 111 is formed
to provide a limit stop, or support for the lower end of the
stem 117. This limit stop is integral with the body plate
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and is formed by bending over that portion of the body which
extends under the swivel tube, as at 117 (see Figure 25
where this feature is ~est illustrated).
The swivel tube in this form of the invention
occupies the same position and angularity relative to the
circular body plate member 80 as in the previously described
form and the wheel and axle assembly is mounted in the body
plate structure in the identical manner and relationship so
that the caster wheel 90 is adapted to rotate relative to
this body frame member in the same manner as described
for the assembly illustrated in Figure 19.
PRECISION CAST BODY FR~E M~BER
Figures 26, 27, 28 and 29 illustrate another
embodiment of the invention wherein a precision cast, skele-
tonized body frame member is utilized to mount the wheel
instead of the dished circular plate of the previous forms
of the invention. The same wheel structure is used with
this body frame and therefore the same reference charact-
ers have been used in Figure 26 for the wheel assembly as
was used in describing the wheel structure of Figure 19 since
the wheel assemblies are identical. The cast body frame
120 is not continuous around the entire circumference of
the caster but is of a skeletonized open framework type of
construction including two segments 121 and 122.
The segment 122 is of open construction as at 123
includes a rim portion 124 integrally connected with a cen-
trally disposed axle socket 125 by ribs 126. The axle
socket includes an integral enclosed end wall 127 whereby
the mounted end of the axle 83 is fuIly enclosed within the
. ,,
~ 30 socket where it is supported and held against rotation. The
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axle, having the wheel structure assembled thereon, is
pressed into the socket 125 and may be provided with serrations
(not shown) further to prevent relative rotation. The axle
83 may be driven into the socket 125 and this operation
is facilated by the contact engagement of theclosed hub
end 101 with the axle head 107.
The segment 121 also includes a rim 128 connected
with the axle socket structure 125 by intermediate body
structure 129 including an integrally formed swivel tube
130. The structure connecting the rim 128 and socket
structure 125 is quite substantial because the stresses
involved in supporting and transferring the loads en-
countered in actual use are very heavy and must be carried
from the mounting stem 131 into the swivel tube structure
130 and into the axle socket 125 and thence to the wheel
assembly rolling on a supporting surface. The forces in-
volved therefore must be transferred between the swivel
mounting adjacent to the rim of the body frame and the central
axle hub so that the structure in this area of the body frame
must be exceptional-ly strong whereas the segment 122 can be
of relatively light construction inasmuch as it merely
provides an attachment for a decorative cover more fully
hereinafter to be described. As best indicated in Figures
28 and 29 the cast body frame structure 129 integrally
connecting the axle socket 125 at the center of the body
frame 120 with the outer segmental rim portion 128 is of
strongly reinforced construction for transferring the stresses
involved between these areas. As shown, the structure 129
is of heavy section with sufficient metal in the section to
carry the forces encountered and as distinguished from the
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10'77209
open framework of the segment 122 the structure 129 of
segment 121 is of continuous closed construction, as best
shown in Pigure 27. The axle socket 125 also is heavily
,. .
reinforced, as best indicated in-Figure 26, for the rigid
mounting of the axle 83 therein.
The integral swivel tube structure 130 incor~orates
its own battom closure, or limit stop, which comprises a
bottom end wall 132 and like the previously described
; swivel tubes this cast structure includes an intermediate tapered
portion 133 affording a seat for stem 131. It will be seen
that this cast swivel tube 130 is also disposed vertically in
the normal operating position of the caster and is disposed at
~; an angle to the operating plane of the body frame which there-
fore is disposed in a canted position corresponding to the an-
gularity of the swivel tube relative to the generally inclined
~ plane of the body frame, as best indicated in Figure 26.
;i Accordingly, the swivel tube structure extends upon both sides
of the general plane of the segment 121 with the u~per main
~ body section disposed to a major extent on the inner side of
,j~ 20 the segment and the bottom end of the swivel tube extending
~;- at least partially through the plane of the segment to the
outer side thereof. This is clearly shown in Figure 28 but
is also indicated in Figure 29 and in Figure 27 as well.
~ODIFIED WHEEL STRUCTURE
~ The caster assembly illustrated in Figure 31 is of
,'~, . .
l slmllar construction to the caster assemblies heretofore
i described but the wheel structure is modified in respect tothe outer wheel member 92. The outwardly extending annular
flange S9 in this modified structure projects outwardly beyond
.. , ~ . .
~" 30 the face of the web portion 94a and provided with a flared
': .
i~ lio 135 that is continuous ana extends entirely around the out-
wardly extended flange. A cover 136 is provided for the outer
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side of the wheel and this cover is centered on the ~heel
by means of an inwardly directed socket 127 which fits
over the closed hub 100 of the outer wheel member 92.
The cover 136 also includes an inwardly directed
annular flange 138 which extends continuously entirely around
the inside face of the cover and engages over the flared lip
135 on the flange 99 to secure the cover on the wheel by means
of a snap-fit engagement of the flange 138 over the lip 135.
The cover 136 may be constructed of nonmetallic material such
as a suitable impact resistance plastic and is shaped to form
a portion of a sphere terminating at the face of the web portion
94a so that the edges thereof are spaced inwardly of the
wheel rim 93 when the covered is installed on the projecting
lip 135.
In this form of the wheel the rim 93 has direct
contact with a supporting surface and rolls on such surface
without the interposition of any part of the wheel cover.
The annular rim 93 and the web portion 94a of the wheel
assembly may have a suitable plating applied thereto as
a decorative feature, if desired, or the rim 93 may have a
nonmetallic tread (not shown) applied therto, such as a suit-
able plastic material, or a resilient tread material, for
use of the caster on uncarpeted floors.
DECORATIVE_CO~ERS ON _~EEL AND BODY FR~lE
As best shown in Figures 19 and 26 the caster
assemblies are provided with decorative metal covers
which are of light weight thin gauge construction and are
mounted respectively on the body frame members and on the
wheel assembly to give the caster assemblies a generally
spherical appearance. The covers are of similar construction
in the form of caster shown in Figure 19 and in the form
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10772V9
shown in Figure 26. The body frame cover 140 is of generally
hemispherical shape and in Figure 19 is crimped over the edge
of the generally circular body plate 80 for attachment
thereto while in Figure 26 this cover is crimped over the
edge of the segmental rim portions 124 and 128 to
provide the attachment and in the areas between the segments
121 and 122 the crimped over portion of the cover is omitted,
as best revealed in Figure 27. However, in the form of the
invention shown in Figure 26, the cover 140 may have a snap~
fit engagement with the segments 121 and 122, if preferred,
and whereby the cover would be snapped onto the rim portions
124 and 128. The cover 140 is provided with an opening 141
for the passage of the swivel tube 111, or 130, as the case
may be, so that the swivel tube is accessible for the mounting
stem 116 or 131.
The cover 142 for the wheel assembly also is of
generally hemispherical shape but includes an offset 143
lying flat against the web portion 94a of the wheel and
extending between the rim portion 144 of the cover and the
central spherical portion 145 covering the outer hub portion
of the wheel assembly. The rim portion 144 lies in full sur-
face engagement with the wheel rim 93 and rolls on the
supporting surface fully backed up by the wheel rim so that
even though the cover 142 is of light weight thin gauge
metal, no damage can be in1icted on the cover flange 144
in the face of its structural support by the wheel rim.
The rim portion 144 of the wheel cover 142 is crimped over
the inner edge of the wheel rim 93 and flanged under the
rim, as at 146, whereby a positive attachment of the cover
onto the wheel assembly is provided. Thus, the covers 140
and 142 fully enclose the caster assembly and provide
a caster of attractive and generally spherical appearance.
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From the foregoing it will be seen that there has
been provided a caster comprised of a generally circular
body frame member which may be axially dished, or disc-like
and aseparate wheel member which may be made from metal
stampings, or at least one from pr~cision castings, which may
be s~eletonized and each having a thin gauge, light weight
cover attached thereto to provide a caster of generally
enclosed form when the several parts are assembled. The
body frame carries a fixed axle which is canted at an angle
: 10 such that the wheel rotates thereon in a plane at an
angle to the vertical and a vertically disposed swivel
socket, also on the body plate, provides for connection of
the caster assembly to an article of furniture, or equi~ment.
By the construction of this design a caster of light weight
has been provided wherein the manufacturing costs have been
substantially reduced and wherein the caster is of suitable
design for efficient manufacture whereby to afford a com-
pleted caster assembly capable of competing with other caster
arrangements on the basis of cost, or light weight.
