Abstract:
A feature of this invention is a positively assembled, double acting spring buffer having all spring guides disposed within and extending the full length of the spring assembly.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to spring buffers for high speed reciprocating mechanisms, and particularly to a recoil adapter for a high rate of fire, recoiling gun mechanism. 
     2. Prior Art 
     The purpose of the recoil adapter is to isolate the gun, as much as possible, from the structure of the installation. The conventional recoil adapter comprises a spring or spindle assembly, a housing and a spindle retainer. A discussion of the design of such recoil adapters is found in &#34;Final Summary Report, Model D Vulcan M61 (TI71E3) and T171E2 20 mm Automatic Guns&#34;, pp 5-30 through 5-38, July 31, 1959, contract DA-30-115-ORD-1 by General Electric Company. Another discussion is found in &#34;Ringfeder Friction Springs In Mechanical Engineering Applications,&#34; Catalogue R53A, May 1975, by Ringfeder Corporation. Buffer units are shown in U.S. Pat. No. 1,120,714 issued to G. G. Hinsdale on Dec. 15, 1914; U.S. Pat. No. 1,317,788 issued to G. G. Hinsdale on Oct. 7, 1919; U.S. Pat. No. 2,876,681 issued to K. W. Maier on Mar. 10, 1959; U.S. Pat. No. 2,638,339 issued to M. P. Taylor on May 12, 1953; U.S. Pat. No. 2,962,935 issued to E. Hepperle on Dec. 6, 1960; U.S. Pat. No. 3,169,757 issued to J. Roder et al on Feb. 16, 1965; and U.S. Pat. No. 3,894,473 issued to M. Marest et al on July 15, 1975. 
     SUMMARY OF THE INVENTION 
     It is an object of this invention to provide a recoil adapter wherein the diameter of the spring assembly is maximized within the diameter occupied by the total adapter. 
     It is another object of this invention to provide a recoil adapter wherein the maximum diameter of the adapter is equal to the maximum diameter of the spring assembly. 
     It is yet another object of this invention to provide a recoil adapter having no housing and a minimum number of parts. 
     A feature of this invention is a positively assembled, double acting spring buffer having all spring guides disposed within and extending the full length of the assembly. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects, advantages and features of the invention will be apparent from the following specification taken in conjunction with the accompanying drawing in which: 
     FIG. 1 is an assembly drawing of a recoil adapter embodying this invention; 
     FIG. 1A is an end view of the spindle tube of FIG. 1; 
     FIG. 1B is an end view of the left end support tube of FIG. 1; 
     FIG. 2 is a perspective view of a spindle tube of the assembly of FIG. 1; 
     FIG. 3 is a longitudinal view in cross-section of the spindle tube ring springs of FIG. 1 in an intermediate stage of assembly; and 
     FIG. 4 is a schematic of the recoil adapter of FIG. 1. 
    
    
     DESCRIPTION OF THE INVENTION 
     The recoil adapter shown in FIG. 1 includes a right spindle tube 12, a left spindle tube 14, a right end support tube 16, a left end support tube 18, a stack of ring springs including alternate inner springs 20 and outer springs 22, and an inner support tube 24. 
     The spindle tubes 12 and 14 are identical and coaxial. Each tube includes an annular main body portion 26 and, integral therewith, a plurality, here shown as six, of longitudinally extending fingers 28. Adjacent fingers are peripherally spaced apart by a slot 30 whose peripheral width is at least equal to the peripheral width of a finger 28. Each finger has a medial, radially outwardly projecting boss 32 having a shoulder surface 34, serving as a compression stop; and a distal, radially outwardly projecting boss 36 having a shoulder surface 38, serving as a tension stop, and a ramp surface 40, serving as finger deflecting cam. The body portion is internally threaded at 42 with a shoulder at 44, and with a diametrical bore at 46. 
     The support tubes 18 and 16 are identical and coaxial with the spindle tubes. Each tube includes a main body portion 48, and, integral therewith, an annular portion 50, and a clevis portion 52. The body portion is externally threaded at 54 with a shoulder at 56, and with a diametrical bore at 58. The clevis has a transverse bore 60. 
     The spindle tubes 12 and 14 are mutually partially telescoped by interlacing their fingers, and an end support tube is threaded into each end and may be fixed by a pin 62 inserted through the aligned bores 46 and 58. Each support tube, e.g. 18, precludes inward deflection of the fingers of the other spindle tube, e.g. 12. 
     The stack of ring springs is disposed on and supported along its entire length by the telescoped tubes 12 and 14 between the tension stops 38 and the compression stops 34 of the right hand spindle tube 12 and the tension stops 38 and the compression stops 34 of the left handle spindle tube 14. The stack is preloaded to fit in this distance &#34;L P  &#34; as shown in FIG. 2. The recoil travel available is the distance &#34;L R  &#34; shown as the open slot length between the proximal end of the slot in one tube and the distal end of the finger of the other tube which rides in that slot as preloaded. The counter recoil travel available is within the distance between the tension stops 38 of the two tubes as preloaded. 
     In assembly, as shown in FIG. 3, the fingers of the tube are passed into the stack of ring springs, the cam surface 40 on each finger serving to deflect the distal end of the finger inwardly to pass within the rings. The other spindle 12 is now passed into the stack from the other end. The preloading force is then applied to the ends of the spindle tubes to compress the stack to permit the fingers of each spindle tube to clear the last ring spring and snap out. The stack of ring springs is now captured on and between the two spindle tubes. The inner support tube 24 is inserted through the open end of the spindle 12 or 14, and end tubes 16 and 18 are screwed in and pinned. 
     The function of the inner tube 24 is to preclude the possibility of buckling of the assembly under compressive, non-axial loading. The end tubes preclude the deflection inwardly of the fingers and loss of the ring springs. Even if the assembly is over-compressed, the ring springs remain captured on the fingers. There are no locking pieces or inserts to fall out and release the tubes from the springs. The stack of ring springs is fully supported along its entire length by the interlaced fingers, and cannot buckle independently of the tubes. 
     Although the embodiment of the invention shown utilizes a stack of ring springs, it will be appreciated that other spring means may be utilized, for example: Belleville discs, a helical compression spring or an elastomeric cylinder.