Note: Descriptions are shown in the official language in which they were submitted.
~2~ 013
B~C~GROUND OF T~IE INVENTION
The present invention relates to a caster assembly and
more particularly to a retractable caster for difficult-to~manage
cases, crates and the like.
There has long been a problem with handling of large or
heavy cases, creates and special materials, e.g. up to
approximately 1,000 lbs to 1,300 lbs, without the aid of powered
assistance, i.e. without forklifts, tow-motors, pallet movers,
winches and the like. It may be necessary to handle such cases in
conditions where such power tools are unavailable or there is not
sufficient space for their use. Even where containers are
relatively light, e.g. 150 lbs to 350 lbs they may be too bulky for
manual handling.
Currently, for military applications, air transport
aircraft utilize a common roller system on a ramp for freight
handling. Various types of containers and cargo are hand-loaded
onto pallets, then placed on the rollers of the aircraft's lowered
ramp, and winched inside where they are tied down securely. Such
cargo may include palletized "battle boxes", medi-cases, ammunition
boxes, projectile cases and other standard types of cargo in
reusab]e containers. on the C-130 ~lercules aircraft, for example,
the roller system weighs approximately 1,700 lbs and takes away
from cargo capacity. As well, in the military and in civilian
industrial and commercial situations, many types of cargo including
engines,
~5~
~cansmi66ion~ and the like are transported in sealed
colltainers. Until now, such containe~s have had to be moved by
forklift, under ideal conditions, or else manually handled.
While it is known to fit conventional casters to the
bottom of hea~y objects to facilitate their moving, the usage
of such casters has been extremely lîmited. If the object,
such as a cargo container, will be frequen~ly carried on an
aircraft, truck, boat or the like, where it will be subjected
to irregulae and possible sudden motion, such casters have
~roven unsuitable as they must be eemoved during transit, or
the container firmly tied down.Obviously there is not a problem
with such casters on the bottom of heavy furniture which will
not be frequently moved.
It is an object of the present invention to provide a
type of caster which may, if required, be perrnanently secueed
to cases, ccates, seeciality boxes and the like which are used
for transporting bulky or heavy cargo materials. It is a
fuLther object of the present invention to provide such a
caster which may be fitted on new containecs or the like, oc
retro-fitted on old ones, arld which will instantly facilitate
the manual handling, without the aid of powered assistance, o~
such containers and the like.
o0
SUM~RY OF THE INVENTION
In accordance with the present invention, a
retrac~.able caster is provided to facilitate moving an object.
The caster comprises a frame h~ving a planar base and sides
circumscribing the base to form a cavity having an opening.
The frame is secured to the bottom of the objec~ in either
recessed fashion or externally. ~ first rigid flap is secured
to the frame by a hinge to swing about an axis between open
position perpendicular to the base and closed position ~arallel
to but spaced fcom the base to close at least a portion of the
opening to the cavity. A wheel is ro~atably supported by a
wheel support assembly secured to the flap. A portion of the
wheel extends beyond the lower edge of the flap when in open
position. An articulated strut is secured to and extends
between a poction of the frame and the wheel support assembly.
The strut folds when the wheel is in retcacted position so that
the wheel, wheel support and strut ace fitted within the cavity
between the base and the flap in closed position. ~ lock is
erovided with the strut foc releasably locking the strut in
opecable position. The strut when locked in operable positivn
rigidly supports the wheel and cover means in open position foc
load beacing purposes.
In a pcefecced embodiment of the present invention, a
second rigid ~lap is secured to the Erame by a hinge at a
location opposite to the first flap to swing about an axis
~5~
parallel to the axis of ~he ficst flap. This second fLap is
seaced a similar distance com the base as the ficst ~lap. The
second flap swings in a dicection opposite to that in which the
ficst flae swings, respectively between open and closed
positions. Confronting edges of the fi~st and second flap when
in closed position meet to close the opening to the cavity.
In another preferced embodiment of the caster in
accocdane with the present inven~ion, th~ wheel support
assembly includes a wheel mount. The wheel is rotatably
secured to the wheel mount foc cotation about an axle secu~ed
to the wheel mount and passiny thcough the wheel. A swivel is
secured to the flap and the wheel mount and extends
therebetween to permit the wheel to pivot about a vectical axis
when the cover means is in open position.
In an alternative preferred embodiment, the wheel
mount assembly is rigidly secured to the flap so that the wheel
cannot turn, celative to the frame, about a veetical axis.
On a s~andard square or rectangular shaped container
or box oc the like, it i~ preferred that a pair of swivel type
castecs in accordance with the present invention be placed at
the bottom fcotlt or rear of the container and a paic of
non-pivoting casters be placed at the other of the bottom,
front or rear.
It wiLl he immediately appceciated that the
retractable castec in accoLdance with the present invention,
when used on the bottom of a containec oe the like,
o~
significantly facilîtates manual portability of that container
when the wheels are lowered, but enables positioning of the
container fiLmly on the floor when the wheels are in retracted
position. Labor savings and forkli~t cost savings arise by
enabling the reelacement of aircraft feeder roller systems by
using the casters of the ~resent invention.
It will be readily understood that, once the casters
are flush mounted on the bottom of a container, crate, box or
the like, the castecs may be ee~cacted in which case the
container, etc. may be handled accocding to conventional
means. Alternatively the casters may be pulled out into open,
operable eosition in which case manual handling of the
container or the like is instantly made possible.
By using the retractable caster in accordance with the
present invention on containers, warehousing and maintenance
centers could benefit tremendously in that quick and easy
movement of materiel, tool boxes, reusable heavy eact stands,
gan~ries, etc., could be achieved. Indeed, any rigid
containers that have to he moved throughout ~he transpocation
sphere, either in a military or civiliatl sense, may be eeadily
fitted with a plural.ity of retractable castecs in accordance
with the ptesent invention to facilitate easiec and speedier
handling theceof, especially where powec handlincJ equipment is
unavailable or impcactical.
35~
BRIEF DESCRIPTIO~ OF T~E DRAWINGS
These and other objects and advantages of the invention
will become apparent upon reading the following detai.led
description and upon referring to the drawings in which:
FIGURE 1 is a perspective view, from the bottom, of a
preferred embodiment of a retractable caster in accordance with the
present invention;
FIGURE 2 is a section view along line II-II of FIGURE l;
FIGURE 3 is a section view along line III~ of FIGURE
2;
FIGURE 4 is a bottom plan view of the caster of FIGURE
1 with khe wheel in retracted position;
FIGURE 5 is a perspective view from the bottom of an
alternative preferred embodiment of caster in accordance with the
present invention; and
FIGURE 6 is a detail view in perspective of the strut
members of the casters of FIGURES 1 to 5.
While the invenkion will be described in conjunction with
example embodiment, it will be understood that ik is not intended
to limit the invention to such embodiments. On the contrary, it is
intended to cover all alternatives, modifications and equivalents
as may be included within the spirit and scope of the invention as
defined by the appended claims.
" ~z~s~o~
DETAILED DESCRIPTI0~ OF THE INVENTION
In tha following descriptiorl, similar features in the
dLawings have been given similar reference numerals.
TuLning to the drawings~ in FIGURES 1 to 4 there is
shown a preferLed embodiment of a retractable caster 2 in
accordance with the present invention. The caster 2 comprises
a frame 4 which may be recessed, as illustrated, for example in
the bottom corner of a cigid container 5, or, alternatively,
externally mounted on the bottom of such a container (not
illustrated) using a~propriate securing means. The frame is
made up of a flat, rec~angular base 6 circumscribed by sides 7
nocmal thereto, the sides and base forming a cavity 8.
An articulated strut member 10 is provided, one end oE
which is secured to fcame 4 and the other end of which is
secured to wheel suppo~t assembly 12 as illustrated (FIGURE
1). To wheel support assembly 12 is secured a caster wheel
14. Secuced to wheel suppoct assembly 12 is a flap 16, which
flap is secured to the bottom e~ge of one of sides 7 of frame 4
by means of hinge 17. ~linge 17 is o~ such a construction that
flap 16 is stopped from opening ~urthec when it reache6
vertical position, normal to base 6 (see e.g. FIGURE 2). ~n
the embodiment illus~cated in E'IGURES 1 to 4, wheel 14 is
permitted to swivel 360 about a vertical axis by means of a
swivel mechanism 18 which is secured to wheel support assembly
12 at the top and at the bottom to U-shaped wheel support
5~0~
member 20 on which wheel 14 is mounted for rotative movement on
axle 22 passing therethrough. Wheel support assembly 12 is rigidly
secured to flap l~.
Articulated strut means 10 comprises a lower strut member
26 secured to wheel support assembly 12 at pivot 28 and an upper
strut member 30 which itself is pivotally secured at pivot 32 to
base 6 of frame 4. These two strut members 26 and 30 are
themselves pivotally secured to each other at pivot 34, portion 36
of upper strut member 30 overlapping a corresponding por-tion of
lower strut member 26 to act as a stop and prevent further relative
rotation of the two strut members once they are in aligned,
operative position, as shown in FIGURE 2. The two strut members 26
and 30 each have a transverse cross-sectional shape of a widened
"U", with a face and upstanding sides normal thereto (FIGURE 6).
This permits the locking of the strut members in aligned,
operational position, as illustrated in FIGURE 2 by means of a
locking pin 38 passing through aligned holes 39 (FIGURE 6). A wire
40 may be used to attach locking pin 38 to frame 4. When wheel 14
is in retracted position, strut members 26 and 30 pivot relative to
each other and to frame 4 and wheel support assembly 12 as
illustrated in phantom in FIGURE 2, so that the wheel 14, wheel
support assembly 12, articulated strut means 10 are all completely
withdrawn into cavity 8.
In the embodiment of the caster illustrated in FIGURES l
to 4, in which wheel 14 is free to pivot about a vertical axis, a
secondary flap ~2 is secured to U-shaped wheel support 20 as
illustrated. This secondary flap is permitted to unobstr~lctedly
_ ~ _
pivot in association with wheel 14 about the vertical axis of
rotation of swivel mechanism 18 and yet, when the wheel is in
retracted position (FIGURE 4), it assists in closing cavity 8.
In FIGURE 5 there is illustrated an alternative
embodiment of retractable caster in accordance with the present
invention, in which wheel 14 is not free to pivot. In this case,
flaps 16 and 42 are replaced by a single flap 43 secured to U-
shaped wheel support 20. As well, wheel support 20 and strut
member 10 are more centred within cavity 8.
In the embodiment of FIGURES 1 to 4 and that of FIGURE 5,
the lower edge 44 of secondary flap 42 (FIGURES 1 to 4~ or flap 43
(FIGURE 5) is such that the wheel 14 extends below it when in
vertical, operative position. As well, this lower edge 44 is
contoured to mate with lower edge 45 of flap 46 which is secured to
the bottom edge of opposite side 7 from that to which flap 16 or 43
is secured. Flap 46 is secured to this opposite side 7 by means of
a hinge 4~. A lock mechanism 50 is secured to the inner surface of
flap 46, an opening 51 being provided in flap 46 as illustrated in
FIGURE 4 to permit manipulation of lock 50. Lock 50 is provicled
with a latch mechanism 52 cooperating with a portion of a
corresponding side 7 to releasably maintain flap ~6 in closed
position (phantom, FIGURE 2), flap 46 cooperatincJ when in this
closed position with flaps
-- 10 --
~s~
16 and ~Z (FIGURES 1 to 4) or flap 43 (FIGURE 5) to close
cavity 8 when the casteL wheel 14 is in retracted position.
wire 54 is secured to frame 4 and to Elap 46 to prevent the
flap from opening beyond the position illustrated in F'IGURE 2.
In this eosition, wheel receiving fingeLs 58 which are secured
to the interior surface of flap 46 receive wheel 14 as it is
being retracted into cavity 8, and then cause flap 46 to move
to closed po~ition with flap 16/42 or Elap 43. Lower edge 44
of flap ~2 (FIGURES 1 to 4) or of flap 43 (FIGU~E 5) is
provided with a slight indentation as illustrated so that lower
edge 45 of flap 46 will support it, when in closed position as
illustrated, with flap 46 then being generally flush with flaps
16/42 or flap 43.
When not in use, locking pin 38 for strut members 26
and 30 may be held in spring clips 64 (F'IGURE 2) mounted on the
side, for example, of strut member 30.
The components Eor manufacturing retractable casters
in accordance with the present invention may be selected
dependent upon the intended use or uses for the casters. Any
heavy duty ca~3ter, for example, may be used together with for
example mild steel stainless steel hinges, eaddle handle
recessed latch 50, steel strut members 26 and 30. 5teel frame
4 and flaes 16/42 or ~3 may be used, ~oc example. Pre-dr;.lled
holes 66 may be ~rovided in flange 6~ about the lower edge of
sides 7 for mountirlg, in a recessed Eashion, the caster of
F'IGURES 1 to 6.
-- 11 --
51~
In o~eration, the reteactable castec 2 in accordance
with the present invention is simply and quickly deployed and
retracted. It may be flush or e~eLnally mollnted, and straight
or swivel a~ting as cequired. The fcame 4 holding the
retrac~able caster wheel 14 is, in the illustrated embodiment,
flush mounted in the corner of a container 5 preferably with
two straight and another swivel caster. In some instances,
more than four casters may be necessary, deeending upon the
length of the container to be equipped. Exact placement may
correseond to that foc bolt-on or welded-on casters.
Once installed, to deploy the casteL 2, flush lock 50
mounted on flae ~6 is pulled, thereby freeing flap 46 to open.
With the help of gravity, flap 46 and then flaps 16/42 (FIGURES
1 to 4) or flap 43 (FIGURE 5) togethec with wheel 14 and st~ut
assembly 10 drop into open, opecative position. Locking pin 3~
is then passed into aligned holes 39 to secure strut members 26
and 30 in aligned, operative position. The caster 2 is then
ready foc use.
To Letcact cas~er 2, pin 38 i8 pulled from aligned
holes 39. ~rticulated strut assembly 10 and associated wheel
supeort assembly 12 and wheel 14, togethet with its associated
flaps, are then free to fold up into closed position simply by
pushing wheel 14 and flaps 16/42 (E~IGURES 1 to 4) oc flae 43
(FIGURE 5) up into closed positicln at the opelling o~ cavity ~.
The caster wheel 14 itself picks up and draws into closed
position flap 46 by means o~ fingers 5a ~ When pushed up flush,
~3~
in closed po~ition, lock 50 then locks Elaps ~6 and 16 - ~2 or
43 into place in closed position. In the embodiment of F'LGURES
1 to 4, where secondary flap 42 is free to swivel with reseect
to flap 16, the wheel and flap 42 must be appropriately aligned
with respect to flap 16 as the wheel is retracted, so that the
wheel will pick up fingers 58.
~ s can be seen in FLGURE 2, a hole 60 may be provided
in secondary flap 42 to provide access to nut 62 holding wheel
14 on axle 22, for example to replace wheel 14 if worn or
damaged.
The retcactable caster assembly in accordance with the
present invention, it will be understood, will have many and
varied uses in cacgo and freight handling for airplanes, trucks
and boats. Warehousing, grocery s-tores, courier services,
contractors and manufacturing businesses, and the military,
whece large, bulky and/or heavy freight containers are handled,
wil]. find practical uses for casters in accocdance with the
pre~ent invention.
Thus it i~ apparent that thece has been provided in
accordance with the invention a retractable caster assembly
that fully 6atisfie6 the objects, aims and advalltages set forth
above. ~hile the invention has been described in conjunction
with specific embodiments theceof, it is evident that many
altecnatives, modifications and variations will be apparent to
those skilled in the art in light of the Eoregoing
description. ~ccordingly, it is intended to embrace all such
- 13 -
5~0C)
alteLnatives, modifications and va~iations as fall within the
spirit and broad scope of the invention.
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