Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TIRE CHANGING APPARATUS
.
This application is a division of Canadian patent
application Serial No. 333,539 filed August 10, 1979.
BACKGROUND OF THE INVENTION
.
This invention relates to a tire changing apparatus, and
more specifically, to a tire changing apparatus particularly
suited for use in the changing of relatively heavy tire and
wheel combinations as are typically found on trucks.
Many tire changing machines commonly in use today are
quite adequate for their intended purpose when used in changing
various wheel and tire combinations commonly employed in
automobiles. Typically, they include a base mounting a tabletop
or tire receiving surface in an elevated position, usually 30 or
more inches above the underlying surface supporting the machine.
However, wheel and tire combinations employed on a large variety
of trucks may be considerably larger than those used with
automobiles. Thus, even if the tire changing apparatus is
capable of performing tire changing operations on the larger
truck tires, the operator of the changer will be faced with
considerable difficulty in elevating the wheel and tire
combination sufficiently to place it on the tabletop for
servicing purposes due to the considerably increased weight of
the larger truck tire and wheel combinations.
As a consequence, the operator will be quickly fatigued
and considerable ineffiGiency will enter into the changing
process.
Thus, there is a real need for a tire changing apparatus
which eliminates or otherwise minimizes the amount of physical
effort required by an operator thereof and yet which still
allows the servicing of tires of relatively large size in an
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efficient and expeditious manner.
SUMMARY OF THE INVENTION
It is the principal object of the invention to provide a
new and improved tire changing apparatus. More specifically, it
is an object of the invention to provide a tire changing
apparatus which is capable of changing relatively large and
heavy wheel and tire combinations with a minimum of physical
effort required on the part of the operator.
According to the invention of primary concern in this
divisional application, there is provided a bead loosener for
loosening a tire from a wheel including a base. A ~-shaped
support element having a straight bight and generally parallel
legs extending therefrom is also provided. Means pivot the legs
to the base for rotation of the U-shaped member about a
generally horizontal axis. A pair of carriages are mounted on
the bight for slidable movement thereon towards and away from
each other. A pair of bead loosening assemblies, one on each
carriage, are provided and are movable with the respective
carriages towards and away from each other. A reciprocal motor
extends between and interconnects the carriage and is operative
to provide relative movement between the carriages for bead
loosening purposes.
The operator of the bead loosener need only roll the
tire, in an upright position, to a location between the bead
loosening shoes to position the same for bead loosening.
In a highly preferred embodiment of the invention, a
tire changer and a bead loosener share a common base with the
path of movement of the bead loosening shoes being transverse to
the horizontal axis of rotation of the tabletop on the base so
that the wheel and tire can be rolled between the two with
little or no need for the operator to additionally revolve the
tire about a diameter thereof when moving from one position to
the other.
The tire changer as disclosed includes a base having a
lower extremity to support the base on an underlying surface.
There is also provided a tabletop having wheel securing means
thereon. Means mount the tabletop on the base for pivotal
movement about a generally horizontal axis between a generally
horizontal, tire changing position and a generally vertical,
wheel loading and unloading position whereat the securing means
is in sufficiently close proximity to the underlying surface
supporting the base so as to be engageable with and securable to
an upright wheel and tire on the underlying surface. Means are
provided for selectively pivoting the tabletop between the two
positions.
As a consequence of the foregoing construction, a wheel
and tire need only be rolled into proximity to the tabletop when
in a vertical position, secured thereto and the tabletop
pivoted to the tire changing position. The only effort required
on the part of the operator is that of rolling the tire along
the underlying surface to the location of the tire changer.
Other aspects and advantages will become apparent from
the following specification taken in connection with the
accompanying drawings.
DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view of a tire changing
apparatus made according to the invention;
Fig. 2 is a somewhat schematic, elevational view of a
tabletop employed in the invention;
Fig. 3 is a plan view of the tabletop with parts broken
away and other parts shown in section for clarity;
Fig. 4 is a side elevation of a bead loosener
employed in the invention with parts broken away for clarity;
Fig. 5 is a horizontal section taken approximately
along the line 5 - 5 of Fig. 4;
Fig. 6 is a view of a tire changing tool which
may be used with the tire changer, appearing with Figure 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to Figs. 1 and 2, an exemplary
embodiment of a tire changing apparatus made according to
the invention is illustrated and generally designated 10.
The apparatus 10 is supported on an underlying surface
such as a floor or the like and includes a rectangular
frame 12 of low profile and a somewhat higher housing 14.
The low profile frame 12 mounts a tire changing tabletop
16 while the housing part 14 of the apparatus 10 mounts a
bead loosening assembly, generally designated 18.
The apparatus 10 also includes an upright, open-
ended tube 20 which may receive a tire changing tool 22
when not in use for storage purposes.
The tabletop 16 includes a rectangular upper plate
24. Centrally, within the plate 24 is a tire tool receiving
fixture 26 which can receive the tool 22 for purposes to
be seen. Slots 28 at spaced locations in the plate 24
reciproca~ly guide tire securing clamps 30 toward and away
from the fixture 26. In the preferred embodiment, there
are three such clamps 30 each equally an~ularly spaced by
about 120.
One edge 32 of the plate 24 mounts a downwardly
depending plate 34 (Fig. 2) which in turn mounts apertured
tongues 36. Pivot pins 38 extend through the tongues 36
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and corresponding lugs 40 (only one of which is shown in
Fig. 1) on the frame 12 ~o ~s to mount the tabletop 16
for rotation about a gencrally hori7.0ntal axis.
As seen in Eig. 2, when the tabletop 16 is in a
solid line position, it is disposed for a tire changing
operation. ~en, however, the tabletop 16 is shifted to
the dotted line position in Fig. 2, it is in a wheel
loaaing and unloading position.
To provide for such movement, a fluid cylinder
44 is pivotally connected at 46 to an appropriate part of
the frame 12 and has its rod 48 pivotally connected by a
pin 50 to the tabletop 16.
As also can be seen in Fig. 2, the grippers 30 have
radially inwardly opening notches 52 for the purpose of
gripping the exterior of the rim of a wheel. One of the
slots 28 is located such that its corresponding gripper
30 moves in a path generally transverse to the edge 32
which is parallel to the horizontal axis defined by the
pivot pins 38. ~hus, with the tabletop 16 in its vertical
position as shown Fig. 2, the notch of the associated rim
clamp 30 will open upwardly. A wheel and tire, with the
beads thereof prPviously loosened, may be rolled into
proximity to the tabletop 16 such that the rim of the
wheel overlies the notch 52. The grippers 30 may then be
moved by means to be described hereinafter radially inwardly
on the tabletop 16 and during such movement, the notch 52
on the lowermost gripper 30 will engage the rim of the
wheel to elevate the wheel until such time as the remaining
clamps 30 cngage the rim at which time the wheel wil] be
centered on the tabletop 16 about tile fixture 2~. This
feature of the invcntion eliminates any need for the
operator of the tire changer to elevate a ~heel and tire
combination to place the same on the table. It will be
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apprecia~ed t~lat clamps of t~e t~p~ havillg ra~ially outwardly
Openillc3 notches or the ii~e ~or engaging the inner
su~face of the wheel rim can be used in lieu of those
illustrated. In such a casc, the clamps will be initial-
ly located at their radially innermost position with
rcspect to the fixture 26 and move radially outwardly.
In such a case, the grippers corresponding to the upper-
most grippers 30 shown in Fig. l ~ould serve to elevate
the tirc and center the same with respect to the fixture 26.
Turning now to Fig. 3, a housing like frame
structure 60 is secured to the undersurface of the plate
24 and mounts a bidirectional motor 62 having a rotary
output mountin~ a gear 64. The gear 64 is engaged with
a rather large gear 66 which in turn is suitably rotatably
journalled by bearings not shown and which drives a
bushing 68 having a hexagonal interior 70. The bushing
68 forms part of the tool receiving fixture 26 and a tire
changing tool may be received within the openi~g 70 to
be rotated upon energization of the motor 62.
A disk 82 is also suitably journalled beneath the
plate 24 concentrically with the gear 66 and includes a
radially outwardly directed tab 84. A cylinder 86 is
pivoted as at 88 to the tabletop and its rod 90 is pivoted
as at 92 to the tab 84. Thus, by extension or retraction
of the rod 90 through the direction of fluid to the
cylinder 86, the disk 82 can be bidirectionally rotated as
indicated by an arrow 94.
Plate-like guides 96 ar~ aligned with the slots 28
and guide blocks lO0 on which the grippers 30 are suitably
mounted as desired. Links 102 are pivoted at lO4 to the
disk 82 and at 106 to the blocks lO0. Thus, and with
reference to Fiq. 3, when the disk 82 is rotated in a
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countercloc`~wise dircction, t~c blocks 100 wil~ bc movcd
radially inwardly causing A corres~onding movement of thc
grippers 30. Conversely, ~hen the disk 82 is rotated in
a clockwise direction, ultimately, the grippers 30 will
be moved radially outwardly.
It will be observed tha~ this arrangement provides
for simultaneous movement of the grippers 30 in the same
direction and at the same rate to provide the aforementioned
centering action. The use of the cylinder 86 to drive
the clamps 30 ensures that the previously mentioned lifting
function thereof for loading purposes requires no more
effort on the part of the operator than that required to
operate a suitable control for the cylinder 86.
Returning to Fig. 1, a control handle 110 extends
upwardly from one side of the frame 12 and may be employed
to operate suitable valving for control of the cylinders
44 (Fig. 2) and 86 (Fig. 3). The particular means utilized
form no part of the present invention but it is contemplated
that fore and aft movement of the handle 110 relative to
a neutral position can be utilized to control the cylinder
44 for moving the tabletop 14 between the two positions
shown in Fig. 2. Leftward movement of the handle could
be used, for example, to cause the clamps 30-to mo~e
radially outwardly while rightward movement of the handle
110 could ~e used to cause radially inwaraly movement of
the grippers 30.
A typical tool 22 IFisure 1~ to be used in conjunction
with the fixture 26 is more fully illustrated in Fig. 6 and
includes a shaft 112 of hexagonal exterior configuration term-
inating in a bevel ll4 for receipt within the bushing 68. Theupper end of the shaft 112 is provided with a transversely
extending sleeve 116 having a square internal cross~section
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to slid~l)ly receive a squar~ tube ]18. One etl~ of the
tubc- 118 mounts a ~ool head l20 which may be of any
suitable configuration kno~n in the ~rt and which is
enlarged sufficiently so as to be impassable through
the sleeve 116.
The other end of the tube 118 mounts a spring
finger 122 which extends exteriorly of the tube end 118
and which terminates in a tab 124 thereat. The tab 124
extends beyond the periphery of the tube 118 and is such
as to normally engage the end of the sleeve 116 if it is
attempted to remove the tube 118 therefrom. When removal
is desired, the tab 124 may be moved upwardly as seen
in Fig. 6 ag~inst the bias of the spring finger 122.
The foregoing structure provides for ready radial
adjustment of the position of the head 120 for wheels
of varying sizes. It also permits relatively rough
treatment of the ~ool without concern for the components
thereof becoming inadvertently disassembled to become lost
or to strike a person in the vicinity of the tire changer.
Turning now to Figs 1, 4 and 5, ~he bead loosener
assembly 18 will be described in greater detail. As seen
in Fig. 1, the housing part 14 of the apparatus 10 includes
an open side 130 remote from the tabletop 16. The upper
surface o~ the housing 14 is also partially open as at
132 immediately adjacent the open side 130.
Within the housing 14 is a U-shaped structure 134
having an elongated bight 136 which is straight and which
may be formed by a rectangular tube or the li~e.
The U-shaped member 134 includes legs 140 extend-
ing from opposite ends of the bight 136 tot~ards the
opening 130. At their ends, the legs 140 are pivoted by
pins 142 to the housing part 14 of thP apparatus 10 so as to
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mount the U-s~laped ~lement 134 for rotation ~ithin the
housing about a generally horizontal pivot axis.
From Fig. 1, and the dcscription that follows
hereinafter, it will be seen that the pivot axis defined
by the pins 142 is trans~erse, that is at riyht angles,
to the pivot axis defined by the pins 38.
Two carriages 150 are slidably mounted on the
bight 136 for movement towards and away from each other.
As best seen in Fig. 4, each of the carriases 150 is
defined by upper and lower plates 152 and 154 respectively
suitably secured together and mounting rollers 156 on
opposite sides of the bight 136. Thus, the carriages
150 may move with a relatively small amount of friction
towards and away from each other.
A cylinder 158 is pivotally connected at 160
to the lefthand carriage lS0 and has its rod 162
pivotally connected at 164 to the righthand carriage lS0.
Thus, by extending the rod 162, the carriages may be moved
to their most spaced positions as illustrated in Fig. 5
while through retraction of the rod 162, they may be
moved towards each other.
The plates 1S2 and 1S4 comprising each of the car-
riages lS0 have a longer length than that of the legs 140
of the U-shaped member 134 so as to extend through the
openings 130 and 132 in the housing part 14. At their ends
remote from the bight 136 they mount facing bead looseniny
assemblies 170 and 172. Each of the assemblies 170 and
172 are comprised of a fixed shoe 174 and a movable, inner
shoe 176. Each of the shoes 176 is pivoted at 178 to
the supporting structure for the fixed shoe 174 so that
they may move relative to the fixed shoes 174.
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The shoe ass~mbly 172 also mounts an outwardly
extending stop 179 ~hich is adapted to engage the rim
of a wheel during a bead loosel~ing process.
In use, a tirc and tlheel, in an upright position,
is rolled into the space betweell the shoes 170 and 172.
A handlc 180 suitably secured to the U-shaped member
134 is moved so as to pivot the entire assemblage
about the pivot axis defined by the pins 142 so as to
bring the shoes 174 to a position transverse to a radius
of the wheel and immediately adjacent the rim thereof.
The cylinder 158 is then operated to retract the rod
162 by means of valving operated by a foot pedal 182.
Initially, the fixed shoes 174 will engage the side walls
of the tire immediately adjacent the rim and upon
continued movement towards each other, friction will
cause the movable shoes 176 to be directed inwardly to
the space between the bead and the rim to fully loosen
the same. It will be observed that since the connection
of the cylinder 158 is between two movable parts of the
structure, namely, the carriages 150, to initiate the
process, the wheel need not by precisely centered with
respect to the space between the shoes 174. In this
respect, operation o~ the bead loosener ta~es place
with a self-aligning feature thereby requiring the
operator only to roll the tire to the general space
between the shoes 174 and not precisely locate it therein.
Thus, operator effort is minimized.
A further feature of the invention is the fact
that the U-shaped member 134, the carriages 150, the shoes
170 and 172, and the cylinder 158 are also constructed
and arranged with respect to thc pivots defined by the
pins 142 such that the center of gravity, designated CG
in Fig. 4, is i~mediately adjacent the pivot axis but
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slightly spacedthcrefrom in thc direction of the bight
136. As a consequ~nce, the adju~stah]e part of the
assembly required for adj~stment to ~heels of varying
sizes is very nearly balancc~ so tllat only a minimal
amount of force need be exerted on the handle 180 to
appropriately position the same. At the same time,
when force is removed from the handle 180, as will be
the case when the device is not in use, the particular
location of the center of gravity will cause the adjustable
components to pivot about the pivot axis 142 to~ard the
position illustrated in dotted lines in Yig. 4 without
the need of springs or other biasin~ means. This
aùtomatically assures, with a minimum of mechanical
components, that the floor space occupied by the bead
loosener when not in use is minimized.
It will be appreciated from the foregoing description
that all facets of tire changing and bead loosening require
a minimum of physical effort on the part of the operator.
Physical ef~ort is further minimized by the unique
orientation of the bead loosener 18 with respect to the
tabletop 16. It will be recalled that the pivot axis for
the tabletop 16 is transverse to the direction of movement
of the bead looseners. This orientation minimizes the
effort required on the part of the operator in moving the
tire and wheel from the bead loosener to the tabletop.
In particular, the path of movement of â tire and wheel
to the proper position with respect to the bead loosener
is parallel and only a short distance away from the path
of movement of a tire and wheel toward the proper position
wich respect to the tabletop 16 when it is in a loading
position. Thus, the main effort required on the part of
the operator is merely rolling the tire in a relatively
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straight line with minimal pivoting of the tire about one of its
diameters.
As a consequence, the efficiency of the tire changing
process is maximized.
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