Patent Publication Number: US-9415492-B2

Title: Pneumatic compressor assembly and method of repairing a transmission

Description:
This utility patent application claims the benefit of priority in U.S. Provisional Patent Application Ser. No. 61/815,870 filed on Apr. 25, 2013, the entirety of the disclosure of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     This document relates generally to the field of repair tools and more particularly to a pneumatic compressor assembly and method for repairing a vehicle transmission. 
     BACKGROUND 
     With the ever increasing price of new automobiles and trucks, more and more consumers are choosing to drive their vehicles for a longer time before trading them in on a new or newer used vehicle. As a consequence, more and more vehicles are undergoing transmission repair to keep them operating properly and on the road. 
     This document relates to a new compressor assembly and related method to quickly and conveniently remove and replace the return spring assembly from a transmission. Advantageously, the compressor assembly and method substantially reduce the repair time necessary to complete this operation. In fact, use of the compressor assembly and method may save the mechanic, on average, between 15 and 20 minutes when completing the transmission repair. 
     SUMMARY 
     In accordance with the purposes and benefits described herein, a compressor assembly comprises a frame, an actuator carried on the frame and a tool secured to the distal end of the actuator. In one embodiment the actuator is a pneumatic actuator including a cylinder and a piston. Further the assembly includes a pressurized air source and a control valve for operating a pneumatic actuator. The tool may include a cross rail, a first set of adjustable spring compression fingers and a second set of adjustable spring compression fingers. The first and second sets of spring compression fingers are carried on the cross rail. 
     In addition the assembly may include a ram having a first end connected to the piston of the actuator and a second end connected to the tool. The ram may include multiple segments that are connected together in different ways to allow length adjustment. 
     In accordance with another aspect, a method of repairing a transmission is provided. That method may be broadly described as comprising the steps of: (a) engaging and compressing a return spring assembly of the transmission clutch with a pneumatically operated compression assembly, (b) removing a retaining ring of the transmission clutch return spring assembly while the return spring assembly is compressed to allow removal of the return spring assembly and disassembly of the transmission for needed repairs. The method may further include compressing the return spring assembly quickly, efficiently and in a controlled manner by engaging the control lever with a single hand. 
     In accordance with yet another aspect, a method is provided for repairing a transmission using a compressor assembly including an actuator, a ram and a tool secured to the end of the ram. That method comprises the steps of: (a) adjusting the compressor assembly to match a depth of a housing of the transmission to be repaired, (b) engaging and compressing a return spring assembly of the transmission with the tool, (c) removing the retaining ring while the return spring assembly is compressed and (d) releasing and removing the return spring assembly from the transmission. The method may also include connecting multiple segments together to provide a ram of desired length. Further the method includes the steps of reseating the return spring assembly in the transmission, engaging and pressing the return spring assembly with the tool, securing the retaining ring in position to hold the return spring assembly in the transmission and releasing the tool from engagement with the return ring assembly in order to complete the operation. 
     In the following description, there is shown and described several preferred embodiments of the compressor assembly and transmission repair method. As it should be realized, they are capable of other, different embodiments and their several details are capable of modification in various, obvious aspects all without departing from the assembly and method as set forth and described in the following claims. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not as restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE PHOTOGRAPHS 
         FIG. 1  is a perspective view of the pneumatic compressor assembly or device. 
         FIG. 2  is a view similar to  FIG. 1  but showing all five ram segments secured to the threaded end or fastener at the end of the piston of the pneumatic actuator. 
         FIG. 3  is a detailed perspective view of the tool. 
         FIG. 4  illustrates the step of compressing a return spring assembly of a transmission with the aligned compression fingers of the tool. 
         FIG. 5  illustrates the step of removing the retaining ring while the return spring assembly is compressed. 
         FIG. 6  illustrates the return spring assembly following removal of the retaining ring. 
         FIG. 7  illustrates the return spring assembly after the compression fingers have been retracted. 
         FIG. 8  illustrates the removal of the return spring assembly from the transmission. 
     
    
    
     DETAILED DESCRIPTION 
     As illustrated in  FIGS. 1-3 , a pneumatic compressor assembly  10  includes a frame  12  having a base  14 , a first upright  16 , a second upright  18  and a crossbar  20 . The frame  12  is made from a high strength material such as steel. The various members of the frame  12  including the base  14 , first upright  16 , second upright  18  and crossbar  20  may be welded or otherwise secured together as desired. 
     A pneumatic actuator  22  is secured to the crossbar  20 . The pneumatic actuator  22  is of a type known in the art including a cylinder  24  and a reciprocating piston  26 . Such an actuator  22  may, for example, have a 5.08 cm bore and a 7.62 cm stroke. In another embodiment, the actuator  22  may have a bore of 5.08 cm and a stroke of 2.54 cm. The piston  26  extends through an opening (not shown) in the crossbar  20  and is pointed toward the base  14 . The end of the piston  26  is threaded or includes a fastener  28  for receiving and holding a ram  29  made from a series of ram segments  30   a - 30   e  (including cooperating fastening/jam nuts). In the illustrated embodiment, the ram segments  30   a - 30   e  are secured together in series by cooperating screw threads. As should be appreciated, each ram segment  30   a - 30   e  may be of the same or different lengths. Two or more of the ram segments  30   a - 30   e  are connected together to form a ram  29  of desired length to allow the user to service different depth transmission housings (e.g. ram lengths of two inches, four inches, six inches, eight inches and ten inches). The operator simply fastens or secures the appropriate ram segment  30   a - 30   e  to the distal end of the piston  26 . 
     A tool  32  is secured to the distal end of the ram  29  by any appropriate means including, for example, an arcuate retainer  34 . As best illustrated in  FIG. 3 , the arcuate retainer  34  is received around the distal end of the ram  29  and provides a friction fit. The tool  32  further includes a cross rail  38  that receives and holds first and second sets of adjustable spring compression fingers  40 ,  42 . Each set of spring compression fingers  40 ,  42  comprises two spaced compression tips  44 ,  46 . As should be appreciated, the fingers  40 ,  42  are curved and secured together by a welding or brazing  47  in order to hold the tips  44 ,  46  in the desired spaced orientation. A felt material  45  is provided between the fingers  40 ,  42  at an end opposite the tips  44 ,  46  in order to add drag to the fingers to help keep them in place while pressing. 
     As should be appreciated, the outer finger  42  is slightly longer then the inner finger  40  for each set of fingers. This allows the compression fingers  40 ,  42  to be quickly and conveniently adjusted to the proper size to engage the spring assembly S of a transmission T. More specifically, one slides the first and second set of fingers  40 ,  42  inwardly along the cross rail  38  until the tips  46  engage the side of the spring assembly S. The longer outer tips  46  engage the side of the spring assembly S and hold the inner tips  44  in perfect position to engage and hold the spring assembly S in a retracted position. 
     The pneumatic actuator  22  is operatively connected to a pressurized air source  48  and a control valve  50  by means of pressurized airlines  52 . The operator has fingertip control of the compressor assembly  10  by engaging the control valve operating lever  54 . By pushing the lever downwardly, pressurized air from the pressurized air source  48  forces the piston  26  against a return spring (not shown) to extend from the cylinder  24  downwardly toward the base  14  of the frame  12 . By manipulating the control lever  54  in the opposite direction, pressurized air from the pressurized air source  48  is released and the return spring forces the piston  26  to be retracted into the cylinder  24  and thereby move away from the base  14 . 
     While also useful for other applications, the pneumatic compressor assembly  10  allows one to quickly and efficiently repair a transmission T. See particularly  FIGS. 4-8 . First the operator determines the depth of the housing H of the transmission T undergoing repair. He then selects the appropriate length of ram  29  and constructs it by joining two or more of the ram segments  30   a - 30   e  together. The ram  29  is then connected to the end of the piston  26  by means of the fastener  28 . The tool  32  is then connected to the end of the ram and the transmission T to be repaired is supported on the base  14  of the frame  12  underneath the pneumatic actuator  22 . The first and second spring compression fingers  40 ,  42  are then moved inwardly or outwardly along the cross rail  38  to bring the compression tips  44 ,  46  into proper alignment for compressing the return spring assembly S of the transmission T. The operator then uses a single hand to manipulate the control valve operating lever  54  so as to extend the piston  26  from the cylinder  24  downwardly and compress the return spring assembly S (see  FIG. 4 ). The assembly  10  provides precise control so that the spring assembly S may be compressed just enough to remove the retaining ring R without damaging any transmission components. In one possible embodiment, the actuator  22  only provides for limited travel or extension of about 2.54 cm. This allows the actuator  22  to compress the spring assembly S sufficiently to remove the retaining ring R without distorting any of the springs or damaging the housing. 
     With the return spring assembly S held in a state of compression by the pneumatic actuator  22  through engagement with the compression fingers  40 ,  42 , the retaining ring R is removed using lock ring pliers P (see  FIGS. 5 and 6 ). The operator then again uses a single hand to manipulate the control valve operating lever  54  and retract the piston  26  into the cylinder  24  until the compression fingers,  40 ,  42  are free of the transmission T. As this is done the return spring assembly S is gently released and can then be removed to complete transmission repairs (see  FIGS. 7 and 8 ). 
     Following the completion of repairs, the return spring assembly S is placed in its seating position in the transmission T. The return spring assembly S is then again compressed by operation of the assembly  10  so that one can secure the retaining ring R in position with the lock ring pliers P. The lever  54  is then manipulated to gently release the compressor fingers  40 ,  42  from engagement with the return spring assembly S. 
     The foregoing has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. Obvious modifications and variations are possible in light of the above teachings. For example instead of utilizing multiple ram segments  30   a - 30   e  to provide for ram length adjustment to match the depth of the transmission housing, an adjustable frame  12  could be provided. 
     As another example, instead of the arcuate retainer  34  (which functions to center the tool  32  on the ram  29  while allowing one to slide the tool off the ram when desired), the tool  32  may be attached to the ram by means of a mounting collar  60  and cooperating bolt  62  (see  FIG. 8  embodiment). All such modifications and variations are within the scope of the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.