CA1126643A - Tire changing apparatus - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A tire changer including a base having a lower extremity to support the base on an underlying surface, a tabletop having wheel grippers, a pivot mounting 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 wheel gripper 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 an underlying surface, a motor for selectively pivoting the tabletop between the two positions thereof, a bead loosening device connected to the base and defining a tire and wheel receiving space for receipt of an upright tire and wheel, the head loosening device including at least one bead loosening shoe generally horizontally movable across the space in a direction generally transverse to the horizontal axis.

Description

1~2~ 3 TIRE CHANGING APPARATUS
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This application is a division of Canadian patent application Serial No. 333,539 filed August 10, 1979.
BACKGROUND OF THE INVENTION

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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 1~ti6~
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 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 l~Zti~3 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 .

112t~643 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 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 l~Z~643 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.

_ g _ llZ~43 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 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 112~43 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.

Claims (4)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A bead loosener for loosening a tire from a wheel comprising:
a base;
a U-shaped support element having a straight bight and generally parallel legs extending therefrom;
means pivoting said legs to said base for rotation of said U-shaped member about a generally horizontal axis;
a pair of carriages mounted on said bight for slidable movement thereon towards and away from each other;
a pair of bead loosening assemblies, one on each carriage, and movable with their respective carriages for movement towards and away from each other; and a reciprocal motor extending between and interconnecting said carriages and operative to provide relative movement between the carriages.

2. The bead loosener of claim 1 wherein said carriages each extend from said bight past the end of said legs and said bead loosening assemblies and mounted on said carriages on the side of said pivoting means oppositely of said bight; said U-shaped element, said carriages, said bead loosening assemblies and said reciprocal motor being constructed and arranged to have a center of gravity just to one side of said pivoting means in the direction of said bight whereby said U-shaped element, said carriages, said bead loosening assemblies and said reciprocal motor are substantially balanced about said pivotal axis when a pivotal force is applied thereto by an operator of the bead loosener and yet will pivot under the influence of gravity towards a vertical position when not receiving a force from an operator of the bead loosener to reduce the floor space occupied by the bead loosener when not in use without the use of springs or other biasing means.

3. A bead loosener of claim 1 or 2 and further including a tire changing mechanism including a tabletop pivoted to said base for rotation about a second generally horizontal axis substantially transverse to said first mentioned generally horizontal axis for movement between a tire changing position and a generally vertical wheel loading and unloading position, and wheel gripping means on said tabletop.

4. The bead loosener of claim 1 wherein said bead loosener assemblies and said carriages provide for movement of the bead loosener assemblies in a path toward and away from each other and define a space between said bead loosener assemblies in which a tire and wheel assemblage may be freely disposed without being clamped; and wherein each of said bead loosener assemblies includes a pair of bead loosener shoes, one of said shoes of each assembly being fixed for movement only in said path and the other of said shoes in each assembly being movable relative to the associated fixed shoe to one side of said path, said movable shoes following said fixed shoes as said assemblies are moved toward each other so that said fixed shoes each make initial (claim 4 cont'd) engagement with respective sidewalls of a tire and wheel assemblage disposed in said space between said assemblies and continued movement of said assemblies will cause the movable shoes to substantially frictionally engage the tire and move to said one side of the path and between the tire bead and the rim of the wheel to fully loosen the bead while the fixed shoes prevent movement of the unclamped tire and wheel assembly out of said space and said path.