Tire hook assembly for tire changing machine

Abstract

A tire changer demount tool assembly including a demount tool configured to traverse a predetermined path of motion between a retracted or stored position and an extended or operating position during a tire demount procedure in response to rotational movement of an actuation linkage about a pivot axis.

Description

TIRE HOOK ASSEMBLY FOR TIRE CHANGING MACHINECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application is related to, and claims priority from, co-pending US Provisional Patent Application Serial No. 63 / 561 , 114 filed on March 4, 2024, and which is herein incorporated by reference.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

[0002] Not Applicable.BACKGROUND OF THE INVENTION

[0003] The present application is directed generally towards a tire demount tool assembly and tire demounting procedure on a tire changing machine, and in particular, towards a tire demount tool assembly which includes a tool assembly supporting a tire demount tool for traversal of a predetermined motion path during tire service procedures.

[0004] The process of removing a tire from a wheel rim and replacing it with another tire, referred to herein as tire changing, can be difficult due to the forces required to stretch and draw the beads of the tire over the edges of a wheel rim. In response to such difficulties, machines have been developed to facilitate the tire changing process. Tire changing machines 10, such as shown in Figure 1 and set forth in International Patent Application Publication WO 2023 / 076258 A2, herein incorporated by reference, commonly include a base 12 supporting a clamping mechanism and drive assembly 14 configured to rotate a wheel rim about a vertical rotational axis X1 when the drive assembly 14 and wheel rim are located at a working position on the tire changer 10. One or more bead breaker tools 16 (typically upper and lower tools) vertically adjustable along an upright column exert pressure on the tire surfaces adjacent to thewheel rim to break loose the tire bead seals. A support column 20 is coupled to the base 12 and is rotatable about a second vertical axis X2, parallel to the vertical drive axis X1 of the drive assembly 14 to accommodate a range of wheel assembly sizes. A tool arm 22 is secured to the support column 20 in a fixed orientation relative there to, within an operative range of the wheel assembly secured to the drive assembly. A prior art tool assembly 24, shown in Fig. 2, is coupled to the tool arm 22 by a pivot 26 which is aligned parallel to the support column 20, and which passes through a mounting bracket 28. The mounting bracket 28 rigidly secures a first end of a guide member 30 at an angle relative to a longitudinal axis of the tool arm 22 and the vertical axis X2 of the support column 20. The guide member 30 in turn supports a prior art demount tool assembly 32 having a demount tool 18 (tire hook) configured for movement along an arcuate path to engage the tire bead of the wheel assembly during a tire demounting procedure. The demount tool 18 is a curved member configured with a rounded hook at a working end for engaging and retaining the tire bead. In the prior art demount tool assembly 32 of Fig. 2, an end of the demount tool 18 is supported between a pair of inner flange plates 34 about a pivot axis TH, spaced apart from the guide member 30. At least one spring 36, coupled between a connector on the demount tool 18 adjacent the pivot axis TH and an outer flange plate 38, biases the demount tool 18 towards a tire-engaging position extending below a tire mount / demount head 19.

[0005] During use, the demount tool or tire hook 18, is inserted between the tire bead and wheel rim, and used to pull the tire bead off the wheel rim during rotation of the wheel assembly about the axis X1 by the drive assembly, allowing the tire to be separated from the rim for removal. Movement of the demount tool 18 between extended and retracted positions along the arcuate path is constrained by a controlledlinear motion of the prior art demount tool assembly 32 along the length of the guide member 30, as well as a spring-biased sliding contact of the demount tool 18 against the mount / demount head 19 secured to a second end of the guide member 30, opposite from the mounting bracket 28. Once a tire bead is engaged by the demount tool 18, the demount tool is partially withdrawn along the guide member 30 to hold the tire bead adjacent to the rear surface of the mount / demount head 19 as the wheel assembly rotates.

[0006] While the prior art tool assembly 24 and prior art demount tool assembly 32 provide improved control and positioning for the demount tool 18 during operation of the tire changing machine, the mechanism requires a large volume of space within which to operate, and incorporates numerous exposed moving and sliding components potentially subject to failure. Accordingly, it would be advantageous to simplify the operation of the a tool assembly and demount tool assembly, and to reduced the number of components to occupy an increasingly compact volume of space.BRIEF SUMMARY OF THE INVENTION

[0007] In one embodiment of the present disclosure, a tire changer machine for changing a tire on a wheel rim comprises a base, a drive assembly secured to the base, and a vertical support column located rearward from the drive assembly. The support column carries a tool arm extendable in a fixed orientation towards a rotational axis of the drive assembly, and which terminates at a tool assembly. The tool assembly supports a tire mount I demount head and a tire demount tool configured to selectively move generally vertically between a retracted or stored position, a fully extended or operating position, and an intermediate or tire-holding position in response to rotational movement of an actuation linkage contained within the tool assembly. The rotatingmovement of the actuation linkage about a pivot, tracked by a suitable sensor, moves the tire demount tool in sliding contact with a rear surface of the tire mount I demount head over the range of movement. The tire demount tool is held in the retracted position when the actuation linkage is rotated to a first position, and is biased to rotate clockwise about an axis of the pivot pin towards a second or extended position relative to the tire mount / demount head. Reversed rotational movement of the actuation linkage reverses the movement of the tire demount tool.

[0008] In a further embodiment of the present disclosure, rotational movement of the actuation linkage about the axis of the pivot pin is responsive to extension and retraction of a pneumatic or hydraulic cylinder coupled between the actuation linkage and a fixed framework of the tool assembly.

[0009] In a further embodiment of the present disclosure, the actuation linkage contained within a partially enclosed volume of the tool assembly.

[0010] In a further embodiment of the present disclosure, the tire demount tool is biased for rotation about the axis of the pivot pin by a spring member.

[0011] In a further embodiment of the present disclosure, the rotational movement of the tire demount tool about the axis of the pivot pin is tracked by a sensor providing data corresponding to a position of the tire demount tool to a controller of the tire changing machine.

[0012] In anotherembodiment of the present disclosure, the actuation linkage consists of a bracket coupled for rotational motion about a pivot pin establishing a transverse axis. The bracket defines first and second orthogonal arms locating separated connection points. The first arm extends from the transverse axis to a first connection point at which a motive force for rotational movement of the bracket is received. The second arm, orientated orthogonal to the first arm, extends from the transverse axisto a second connection point receiving the tire demount tool and establishing the pivot axis of the tire demount tool.

[0013] The foregoing features, and advantages set forth in the present disclosure as well as presently preferred embodiments will become more apparent from the reading of the following description in connection with the accompanying drawings.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0014] In the accompanying drawings which form part of the specification:

[0015] Figure 1 is a perspective view of a prior art tire changing system having a toll support and tool assembly;

[0016] Figure 2 is a perspective view of the prior art tool support and tool assembly in Figure 1 ;

[0017] Figure 3 is a perspective view of a tool assembly of the present disclosure, with a left-side cover plate removed;

[0018] Figure 4 is a left side plan view of the tool assembly of Fig. 3, with the tire demount tool in the retracted or stored position;

[0019] Figure 5a is a left side plan view of the tool assembly of Fig. 3, with the tire demount tool in the fully extended position;

[0020] Figure 5b is a left side plan view of the tool assembly of Fig. 3, with the tire demount tool in a intermediate tire-holding position;

[0021] Figure 6 is a left side plan view of the tool assembly of Fig. 3, illustrating paths of arcuate movement for the orthogonally positioned connection points of the bracket; and

[0022] Figure 7 is a right side perspective view of the tool assembly of the present disclosure, with a right-side cover plate installed.

[0023] Corresponding reference numerals indicate corresponding parts throughout the several figures of the drawings. It is to be understood that the drawings are for illustrating the concepts set forth in the present disclosure and are not to scale.

[0024] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings.DETAILED DESCRIPTION

[0025] The following detailed description illustrates the invention by way of example and not by way of limitation. The description enables one skilled in the art to make and use the present disclosure, and describes several embodiments, adaptations, variations, alternatives, and uses of the present disclosure, including what is presently believed to be the best mode of carrying out the present disclosure.

[0026] The present disclosure sets forth and describes a tool carrying component of a tire changer machine. Those of ordinary skill in the art will readily understand the basic operation and generic components of a table-top or spindle-based tire changer machine, such as the base, drive assembly, tool support column, tool arms, rollers, bead breakers, tire mount / demount heads, and operator controls. Accordingly, it will be further understood that such generic components can take a variety of forms and configurations, and form no part of the present invention.

[0027] Turning to Figures 3-7, a tool assembly 100 is located at a proximal end of a horizontally-oriented tire changing machine tool arm 22, within an operative range of a wheel rim and tire assembly secured to an associated drive assembly 14. The tool assembly 100 supports a tire mount I demount head 19 and a tire demount tool 18 configured to move generally vertically between a retracted or stored position (as seein Fig. 4), a fully extended or tire-hooking position (as seen in Fig. 5a) and an intermediate or tire-holding position (as seen in Fig. 5b) in response to rotational movement of an actuation linkage 102 about a pivot. Rotational movement of the actuation linkage 102 displaces the tire demount tool 18 in sliding contact with a rear surface of the tire mount / demount head 19 through the range between the retracted or stored position and the fully extended or tire-hooking position. The tire demount tool 18 is held in a retracted position when the actuation linkage 102 is rotated to a first position (Fig. 4), and is biased towards the intermediate and fully extended positions relative to the tire mount / demount head 19 as the actuation linkage rotates clockwise about the pivot towards a second position (Fig. 5). Reverse movement of the tire demount tool 18 in the opposite direction, towards the retracted or stored position, is by rotation of the actuation linkage 102 in the opposite direction around the pivot.

[0028] In one embodiment, such as seen in Fig. 7, the tool assembly 100 includes a pair of outer cover plates 104 rigidly secured to the proximal end of the tool arm 22 by threaded bolts orother suitable fasteners. The outer cover plates 104 define the lateral sides of the tool assembly 100 to partially enclose a volume of space containing the actuation linkage 102. Within the partially enclosed volume, a laterally oriented pivot pin 106 extends between the outer cover plates 104, and secures an L-shaped lever arm 108 of the actuation linkage for rotational movement about a longitudinal axis of the pivot pin 106. The lever arm may be of unitary construction, or as best seen in Figures 3 and 7, or consist of a pair of parallel plates 108a, 108b coupled by pins 114, 116 at the distal end of each extension portion of the L-shaped lever arm.

[0029] The L-shaped lever arms 108a, 108b each define orthogonally oriented short and long extensions 109a and 109b extending from the location of the pivot pin 106. The short extensions 109a are linked to a shaft 110 of a linear actuator 112 by a pivotpin 114, while the long extensions 109b are linked to the tire demount tool 18 by pivot pin 116. The linear actuator 112 is secured axially opposite the shaft 110 to bracket 118 by pivot pin 120. Extension and retraction of the shaft 110 in response to operation of the linear actuator 112 causes the short extensions 109a to move in a first arcuate path about the axis of the pivot pin 106, which in turn moves the long extensions 109b in a second arcuate path about the same axis. The first and second arcuate paths of movement lie along circles concentric with the axis of the pivot pin 106. Rotational movement about the pivot pin 106 by the lever arm 108 may be monitored by means of a rotary encoder or similar rotational position sensor located in operative proximity to the axis or rotation. Output signals from the position sensor are conveyed to a processor in control of the tire changing system, providing data representative of the position of the tire demount tool 18. Those of ordinary skill in the art will recognize that the linear actuator 1 12 may be driven by a variety of means. For example, as shown in Figures 3-7, a hydraulic cylinder may be utilized to extend and retract the shaft 110. Alternative means include pneumatic cylinders and electrical or mechanical actuation mechanisms.

[0030] Movement of the long extensions 109b in response to the extension and retraction of shaft 110 is transferred to the tire demount tool 18 by pivot pin 116, resulting in cycling of the tire demount tool 18 between the retracted position (Fig. 4) the operating position (Fig. 5a) and the tire holding position (Fig. 5b). Movement of the demount tool 18 is further constrained by a sliding contact of the demount tool 18 biased against a rear exterior surface of the mount / demount head 19 secured to the bracket 118. A spring 122, coupled between a connector 124 on the demount tool 210 adjacent to the pivot pin 116, and a second connector 126 secured to the cover plates 108a, 108b by a retaining rod and bracket assembly 128, biases the demount tool 18towards the operating position in which the demount tool 18 extends below the mount I demount head 19, as shown in Fig. 5a. The spring 122 acts to bias the demount tool 18 forward against the mount I demount head 19 during extension motion, and against the bracket 118 during retraction motion.

[0031] One of ordinary skill in the art will note that various pins securing the demount tool 18, the mount head 19, and the linear actuator 1 12 to the tool assembly may be configured for ease of removal, such as by the inclusion of snap-ring retainers or quickreleases to allow for easy removal, enabling quick and simple removal of the components for replacement or inspection.

[0032] As various changes could be made in the above constructions without departing from the scope of the disclosure, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims

CLAIMS:

1. A machine for changing a tire on a wheel rim, comprising: a base (12); a drive assembly (14) coupled to said base and configured to rotate the wheel rim and an associated tire about a rotational axis (X1 ); a support column (20) secured to said base; a tool arm (22) coupled to said support column, said tool arm oriented towards said drive assembly rotational axis; a tool assembly (100) coupled to the tool arm, the tool assembly including a pair of outer cover plates (104) secured at one end to said tool arm, an actuation linkage (102) secured fora limited range of movement between said pair of outer cover plates, a bracket (118) rigidly secured between said pair of outer cover plates opposite said tool arm, a tire mount / demount head (19) secured to said bracket, and a demount tool (18) partially retained between said pair of outer cover plates and secured to said actuation linkage by a pivot pin (116); wherein said demount tool is biased towards said bracket and a rear surface of said tire mount / demount head; and wherein said demount tool traverses between said pair of cover plates from a retracted position vertically above said tire mount / demount head and an extended position projecting vertically below said tire mount / demount head in response to movement of said actuation linkage.

2. The machine of claim 1 wherein said actuation linkage is secured for rotational movement between said pair of outer cover plates.

3. The machine of claim 1 wherein said demount tool is biased to pivot about said pivot pin by at least one spring (122) to maintain a sliding contact with said mount / demount head.

4. The machine of claim 1 wherein a linear actuator (112) is coupled between said bracket and said actuation linkage, said linear actuator configured to impart said limited range of movement to said actuation linkage.

5. The machine of claim 4 wherein said linear actuator is one of a hydraulic cylinder, a pneumatic cylinder, or an electro-mechanical actuator.

6. The machine of claim 4 wherein said actuation linkage is secured for said limited range of movement between said pair of outer cover plates by a single pivot pin (106) extending transversely between said pair of outer cover plates.

7. The machine of claim 6 wherein said actuation linkage defines a short arm (109a) and a long arm (109b), each arm oriented orthogonal to said single pivot pin, said short arm and said long arm further defining lever arms orthogonal to each other.

8. The machine of Claim 7 wherein said linear actuator is coupled to said short arm of said actuation linkage, and wherein said pivot pin (1 16) securing said tire demount tool to said activation linkage is located on said long arm.

9. The machine of claim 1 wherein said demount tool movement range includes an intermediate position between said retracted position and said extended position, said intermediate position locating a hook portion of said demount tool adjacent a rear surface of said mount I demount head.

10. A method for cycling a tire changer demount tool (18) between a retracted position vertically above a tire mount / demount head (19) and an extended position projecting vertically below the tire mount / demount head, comprising:moving said demount tool from said retracted position to said extended position by rotating an actuation linking (102) in a first direction about a pivot (106) within a tool assembly (100) supporting said demount tool and said tire mount / demount head; moving said demount tool from said extended position to said retracted position by rotating said actuation link in a second direction about said pivot; and wherein said demount tool slides against an outer surface of said tire mount / demount head during both of said movements.

11. The method of Claim 10 further including biasing said demount tool against said outer surface of said tire mount / demount head.

12. The method of Claim 10 wherein rotation of said actuation linkage is responsive to movement of a linear actuator (112).

13. A tire changer configured for demounting a tire from a rim of a wheel assembly, comprising: a structure (14) configured to support and secure said wheel assembly an armature (22) coupled to said structure, said armature positioning a tool assembly (100) in operative proximity to said wheel assembly; wherein said tool assembly includes a movable actuation linkage (102), a rigidly secured bracket (118), a tire mount / demount head (19) secured to said bracket, and a demount tool (18) secured to said actuation linkage; wherein said demount tool is biased towards said bracket and a rear surface of said tire mount / demount head; and wherein said demount tool traverses a range of motion from a retracted position vertically above said tire mount / demount head to an extended position projecting vertically below said tire mount / demount head in response to movement of said actuation linkage relative to said bracket.

14. The tire changer of claim 13 wherein said tool assembly further includes a position sensor operatively coupled to the movable actuation linkage, said position sensor configured to generate an output signal representative of a position of said demount tool within said range of motion; and a controller operatively configured to receive said output signal as feedback for controlling operation of said movable actuation linkage.

15. The tire changer of claim 13 wherein said demount tool range of motion further includes at least one predefined intermediate position located between said extended position and said retracted position.

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