Patent Application
20090013514
1. Field of the Invention
The present invention generally relates to an apparatus for facilitating maintenance of a McPherson type strut assembly. More particularly, the present invention relates to a spring-compression apparatus for enabling users thereof to quickly and safely disassemble and reassemble a McPherson type strut assembly.
2. Description of the Prior Art
In order to properly maintain a strut assembly comprising a high tension strut spring, it is necessary to first compress the strut spring so as to remove or otherwise redirect forces away from structure maintaining the strut spring in a spring-compressed state. Once the strut spring is further compressed and forces are redirected, a mounting nut may be removed from the strut assembly and the strut spring may be decompressed to a relaxed state. The strut assembly may then be maintained or repaired as required. A number of apparatuses have been developed with an eye toward facilitating strut spring compression. Some of the more pertinent prior art relating to strut spring compression devices and the like is described hereinafter.
U.S. Pat. No. 3,814,382 ('382 Patent), which issued to Castoe, discloses a Spring Compressor. The '382 Patent teaches an apparatus for compressing a spring in conjunction with a shock absorber or other similar structure wherein the apparatus includes a frame upon which a spring to be compressed is mounted. An upper yoke member is slidably mounted in the frame and is operatively connected to a power source whereby a bracket is in position to act with a source yoke member to contact a spring being compressed. Downward movement of the yoke causes compression of the spring in a manner that any desired service or operation can be performed on the spring assembly being compressed. The frame further includes a safety mechanism to insure that the spring is safely compressed during service.
U.S. Pat. No. 4,295,634 ('634 Patent) and U.S. Pat. No. 4,395,020 ('020 Patent), which issued to Spainhour, both disclose a Strut Compressor. The '634 and '020 Patents teach a spring compressor employing a fluid operated piston cylinder, which drives a first platen toward a second platen to compress a McPherson type strut mounted between the two platens. The '020 Patent further teaches that the first platen may be pivotally mounted for self-adjustment to accommodate many different strut sizes and designs.
U.S. Pat. No. 4,703,547 ('547 Patent), which issued to Togawa, discloses an Apparatus for Assembling a Vehicle Suspension Mechanism. The '547 Patent teaches an apparatus for assembling a coil spring on a damper strut to manufacture a damper strut assembly. The apparatus includes a clamp for holding the strut in a vertical direction with the lower end of the spring attached to a lower spring seat provided on the strut. A caliper type spring depresser is provided. The depresser is mounted on a plate for movement along a substantially vertical guide rail mechanism. The plate is swingable in a substantially vertical plane so that the direction of movement of the depresser can be adjusted so as to coincide with the direction of the axis of the spring.
U.S. Pat. No. 5,031,294 ('294 Patent), which issued to Krueger, discloses a Strut Spring Compressor. The '294 Patent teaches an apparatus for use in assembly and disassembly of a strut assembly having a shock absorber disposed within a coil spring. The apparatus includes a frame and a first spring engagement member secured to the frame for engaging the first end of the spring of a strut. A second spring engagement member is provided connected to the frame for movement with the frame toward and away from the first spring engagement member.
U.S. Pat. No. 5,680,686 ('686 Patent), which issued to Bosche et al., discloses a Strut Spring Compressor having Floating Compression Head. The '686 Patent teaches an apparatus for use in assembling and disassembling a strut assembly of the type having a shock absorber axially disposed within a coil spring including a frame, a first section connected to the frame for supporting the lower portion of the spring, and a second section for holding the upper portion of the spring or upper spring seat. The second section is movable toward and away from the first section and is arranged for axially compressing the spring as the second section moves toward the first section. The second section includes guide structure, a head, linkage structure, and pivot structure. The guide structure is connected to the frame and is for allowing the second section to move toward and away from the first section. The head is mounted on the guide structure and is for positioning the spring. The linkage structure is connected to the guide structure and is for allowing the head to tilt in a first plane generally parallel to the linear axis of the spring. The pivot structure connects the head to the guide structure and is for allowing the head to tilt in a second plane intersecting the first plane.
U.S. Pat No. 7,103,951 ('951 Patent), which previously issued to the author of the present disclosure, teaches a spring-compression apparatus for facilitating maintenance of a strut assembly comprising a guide member, a carriage assembly, and a rest assembly. The guide member comprises a first member end and a second member end. The carriage assembly comprises a jack assembly and a slide assembly. The jack assembly is operable to otherwise displace the slide assembly along the guide member. The slide assembly comprises a locator assembly, which comprises a locator extension arm and a center locator. The rest assembly comprises a center rest. A first strut end is positionable upon the center rest. The center locator is engageable with a second strut end for compressing the strut spring. The locator assembly further enables a user to remove a mounting nut from the second strut end when the strut spring is compressed, thus enabling strut assembly disassembly.
It may be seen from an inspection of the foregoing, as well as from a consideration of the general state of the art, that the prior art appears to be silent on a strut spring compression apparatus comprising laterally-displaceable, cooperative, pivotable helix-channeling structures for channel-receiving or channel-anchoring a helix type coil or spring of a strut assembly. Further, the prior art appears to be silent on a strut spring compression apparatus comprising a pivotable crown structure for seating upon variously constructed strut assemblies having spring seats, as variously angled relative to the axis of the respective strut assembly. The prior art thus perceives a need for such an apparatus, as summarized in more detail hereinafter.
It is thus a primary object of the present invention to provide a spring-compression apparatus that enables users thereof to quickly and efficiently disassemble and reassemble McPherson type strut assemblies. It is a further object of the present invention to provide a spring-compression apparatus that enables users thereof to disassemble and reassemble McPherson type strut assemblies of various designs.
To achieve these and other readily apparent objectives, the present invention essentially provides a spring-compression apparatus for facilitating maintenance of a McPherson type strut assembly. In this regard, the typical McPherson type strut assembly essentially comprises a first strut end, a strut body, a strut spring, a piston rod, a spring seat, a mounting nut, a second strut end, and a longitudinal strut axis. The piston rod comprises a threaded rod end and the strut axis extends through the strut body and the piston rod. The spring seat comprises a rod-receiving aperture and the mounting nut is threadably received on the rod end adjacent the rod-receiving aperture for maintaining the strut assembly in an assembled, spring-compressed state.
The spring-compression apparatus comprises a guide member, a carriage assembly, and a spring-engagement assembly. The guide member or main upright comprises a first member end, a second member end, and a member length extending intermediate the first member end and the second member end. The carriage assembly comprises a jack assembly and a slide assembly. The jack assembly comprises a jack, certain jack extension means, and certain jack release means. The slide assembly comprises a locator extension arm and a carriage. The carriage comprises a member-receiving tunnel, which tunnel slidably receives the guide member such that the carriage is guided along the axis of the upright guide member. The locator assembly comprises a locator extension arm, a strut end interfacing center locator, and certain nut accessing means.
The spring-engagement assembly preferably comprises a screw mechanism, first and second laterally disposed screw-mounted extension arms, and first and second helix-engaging or coil-engaging channel structures attached to first ends of the extension arms. Second ends of the extension arms are screw-mounted to the screw mechanism, and the screw mechanism is cooperably associated with the guide member such that the screw axis as fixed relative to the axis of the guide member. The screw mechanism thus functions to laterally displace the first and second helix-engaging channels into and out of engagement with the strut spring. The helix-engaging channels each comprise certain channel-like structure such that when laterally opposed arc lengths of the helix or coil of strut spring are received, the axis of the coil centrally located to the channel junctions is relatively fixed in space.
The helix-engaging channel structures are pivotally attached to vertical extensions of the extension arms, which pivotable attachment enables a user to engage a variably pitched strut spring. Stated another way, the pivotally attached helix-engaging channel structures function to enable a user to engage strut springs having varied chirality or coil handedness. One or more of the vertical extensions may comprise means for enabling a user to vertically displace the pivotally attached helix-engaging channel structure to engage variably torsioned strut springs.
The strut spring or coil of the strut assembly is thus graspable by the channel structures for fixing a first end or portion of the strut axis. The jack extension means are thus operable to extend the jack and displace the strut end interfacing device or center locator toward the channel structures. The center locator is thus engageable with the strut end or spring seat for fixing a second end or portion of the strut axis and serving as an interface when compressing or “apparatus-compressing” the strut spring. The nut accessing means enable a user to remove the mounting nut from the rod end after the strut spring is sufficiently apparatus-compressed.
Other objects of the present invention, as well as particular features, elements, and advantages thereof, will be elucidated in, or apparent from, the following description and the accompanying drawing figures.
Other features of my invention will become more evident from a consideration of the following brief description of patent drawings:
a) is an enlarged fragmentary sectional view of the pivotable strut interfacing crown assembly of the apparatus as enlarged from
a) is an enlarged fragmentary sectional view of the right portion of the spring-engagement assembly as enlarged from
Referring now to the drawings, the preferred embodiment of the present invention generally concerns a strut spring-compression apparatus 10 or a strut spring compressor for facilitating maintenance of a McPherson-type strut assembly. The spring-compression apparatus 10 of the preferred embodiment is generally illustrated and referenced in
It will be understood from a general inspection of the noted figures, as well as from a general consideration of a generic McPherson-type strut assembly, that the strut assembly 90 essentially comprises a first strut end 91 as referenced in
The first strut end 91 typically comprises a mounting nut (not specifically illustrated in the accompanying drawings) for retaining the strut spring 93 (a compression coil) in a partially compressed state. In this last regard, the reader is directed to the specification of U.S. Pat. No. 7,103,951 ('951 Patent), which is reflective of the current specification, and composed by the same author, for a more detailed discussion of mounting nut(s) and associated structures. Indeed, certain explanatory specification portions of the '951 Patent may be considered incorporated by reference thereto insofar as the specification may be said to support structures of the strut assembly 90 and subject matter common to both the '951 Patent and the teachings of the present specification.
It may thus be noted that the piston rod 94 preferably comprises a threaded rod end for receiving the mounting nut, and that the strut axis 98 extends through the strut body 92 and piston rod 94. The mounting nut is preferably threadably received on the rod end for maintaining the strut assembly 90 in an assembled, spring-compressed state. As earlier stated the strut spring 93 is a compression coil and is under a considerable amount of compression when strut assembly 90 is in an assembled, spring-compressed state. Thus, there is a significant force being directed against spring seat 95 and the mounting nut when strut assembly 90 is in an assembled, spring-compressed state.
In order to properly and safely remove the mounting nut, the strut spring 93 must first be further compressed so as to remove or otherwise redirect the forces from the compressed strut spring 93 away from the mounting nut so that the mounting nut may be safely removed from the rod end. In this regard, it is contemplated that redirection of the spring-compressed forces is achieved by the introduction of some other structure that further compresses strut spring 93. Thus, it is believed that spring-compression apparatus 10 of both the '951 Patent and the current specification provide excellent means for properly and safely removing mounting nuts from McPherson-type strut assemblies.
The spring-compression apparatus 10 according to the present invention preferably comprises an upright or guide member 20 as generally illustrated and referenced in
It will be seen from an inspection of the applicable figures that guide member 20 preferably comprises a first member end 21, a second member end 22, and a member length extending intermediate first and second member ends 21 and 22. It will be further seen that first member end 21 preferably comprises a jack stop 26 as illustrated and referenced in
Carriage assembly 30 preferably comprises certain carriage displacement means or spring compression means for forcefully displacing the carriage assembly 30 and/or apparatus-compressing a strut spring 93; and certain member engagement means for guiding displacement of the carriage assembly 30 relative to the guide member 20. It is contemplated that the carriage displacement means or spring compression means may be preferably defined by a jack assembly 40 and that the member engagement means may be preferably defined by a slide assembly 50 as both generally illustrated and referenced in
Jack assembly 40 preferably comprises a ram jack or jack 41 as referenced in
Slide assembly 50 preferably comprises a jack pedestal as illustrated and referenced in
It will be seen from an inspection of the noted figures that the jack pedestal 51 may be said to comprise a locator extension arm 58 as illustrated and referenced in
The spring-engagement assembly 80 according to the present invention is central to the practice of the present invention, and is believed to eliminate many of the shortcomings inherently otherwise taught by the '951 patent. The spring-engagement assembly 80 preferably may be said to essentially define certain helix-grabbing means according to the present invention. The helix-grabbing means may thus be said to comprise first and second laterally disposed shaft-mounted extension arms 81; certain arm displacement means for laterally displacing the extension arms; and first and second helix-engaging or coil-engaging channel structures 83 attached to first ends of the extension arms 81 via vertical extensions 56 as illustrated and referenced in
The screw mechanism 82 thus functions to laterally displace the first and second helix-engaging channels 83 into and out of engagement with the strut spring 93. In other words, the helix-engaging channels or channel structures 83 receive laterally opposed portions of the strut spring 93 when displaced into engagement therewith as generally depicted in
The helix-channeling means or helix-engaging channel structures 83 are preferably pivotally attached to vertical extensions 56 of the extension arms 58 as depicted by pivot axes 101 in
From a general inspection of the noted figures, as well as from more particular consideration of
The strut spring 93 or coil of the strut assembly 90 is thus graspable by the structures 83 for fixing a first end or portion of the strut axis. The jack extension means as previously specified are thus operable to extend jack 41 and displace the crown-like end interfacing device or center locator 59 toward the structures 83 as may be understood from a comparative inspection of
It should be noted that the nut accessing means or nut access aperture 60 is sufficiently sized and shaped so as to allow tool or socket structure to be inserted through the nut accessing means and cooperatively engage the mounting nut for removal thereof. Typically, the removal of a mounting nut is achieved via either a pneumatically driven socket-outfitted tool or similar other socket-outfitted tool designed for nut removal. The jack release means as previously specified are further operable to retract the jack 41 and thus fully decompress the strut spring 93 to a relaxed state. Thus, it will be seen that the described spring-compression apparatus 10 enables effective disassembly of a strut assembly such as assembly 90 thereby facilitating maintenance or repair of the target strut assembly.
It is further contemplated that spring-compression apparatus 10 may further preferably comprise certain carriage return means for displacing the carriage assembly 30 toward the first member end 21. In this regard, it is contemplated that the carriage return means may be defined by a compression type gas spring assembly 86 as generally depicted and referenced in
While the above description contains much specificity, this specificity should not be construed as limitations on the scope of the invention, but rather as an exemplification of the invention. For example, it is believed that the spirit of the present invention discloses a spring compression apparatus for facilitating maintenance of a strut assembly, which apparatus may be said to essentially comprise a guide member, a carriage assembly, and a spring-engagement assembly or certain helix- or coil-grabbing means.
The guide member comprises a first member end, a second member end, and a member length extending intermediate the first member end and the second member end. The carriage assembly comprises a jack assembly and a slide assembly. The jack assembly comprises a jack, jack extension means, and jack release means. The jack comprises a stop-engaging end and a pedestal-engaging end. The slide assembly comprises a jack pedestal, a pivotable center locator or strut end interface and a carriage. The carriage comprises an arm-engaging end, a pedestal-engaging end, and a member-receiving tunnel. The guide member is slidably received in the member-receiving tunnel. The center locator is attached to a locator extension arm, which may be an extension of the jack pedestal.
The spring-engagement assembly comprises first and second laterally disposed shaft-mounted extension arms, a screw mechanism disposed between the extension arms, and first and second helix-engaging channel structures attached to first ends of the extension arms. Second ends of the extension arms are screw-attached to the screw mechanism and the screw mechanism is cooperably associated with the guide member for enabling lateral displacement(s) of the extension arms. In other words, the screw mechanism functions to laterally displace the first and second helix-engaging channels into and out of engagement with the strut spring of strut assembly. The helix-engaging channels receive laterally opposed portions of the strut spring when displaced into engagement therewith.
The pivotable strut end interface or center locator is attached to the locator extension arm for interfacing intermediate the first strut end and the locator extension arm. The jack extension means are operable to extend the jack and displace the locator assembly toward the spring-engagement assembly. The strut end interface is engageable with the first strut end for apparatus-compressing the strut spring. The jack release means are operable to retract the jack and fully decompress the strut spring. The spring-compression apparatus thereby enables strut assembly disassembly, and facilitates maintenance of the strut assembly.
Stated another way, the apparatus according to the present invention may be said to essentially comprise a guide member, a carriage assembly, and certain helix grabbing means. The guide member functions to guide the displaceably received carriage assembly, which carriage assembly comprises certain carriage displacement means, certain member engagement means, and a (pivotable) strut end interface (having certain nut accessing means). The guide member is cooperatively associated with the member engagement means for guiding carriage assembly displacement and the carriage displacement means enable carriage assembly displacement. The strut end interface engages a first strut end of a strut assembly. The coil or helix-grabbing means function to laterally grab a strut spring helix or spring coil and fix the axis thereof. The carriage displacement means are operable to displace the strut end interface toward the strut spring helix, which end-engaged strut end interface may well function to apparatus-compress the strut spring helix during carriage displacement.
Accordingly, although the invention has been described by reference to certain preferred embodiments, it is not intended that the novel assembly or apparatus be limited thereby, but that modifications thereof are intended to be included as falling within the broad scope and spirit of the foregoing disclosure, the following claims and the appended drawings.
