US3486515A - Shock absorbers for crutches - Google Patents

Description

Dec. 30, 1969 E3.A A. CHRYSOSTOMIDES SHOCK ABSORBERS FOR`CRUTCHES Filed June 5, 1968 FIG. 1.

If I hill STAVRO A, CHRYSGSTOMIDES BY RWM 1% ATTORNEY Dec.30, 1969 s. A. cHRYsosToMlDEs 3,486,515

SHOCK ABSORBERS FOR-'CRUTCHES Filed June s, 1968 Y 2 sheets-sheet 2 FIG. 5.

` n l' INVENTOR STAVRQACHRYSOSTOMIDES 2,4171v UM/x' ATTORNEY a United States Patent O 3,486,515 SHOCK ABSORBERS FOR CRUTCHES Stavro A. Chrysostomides, Rte. 1, Box 124, Columbia, S.C. 29203 Continuation-impart of application Ser. No. 640,053, May 22, 1967. This application June 3, 1968, Ser.

Int. Cl. A61h 3/ 02; A45b 9/ 04 U.S. Cl. 135-50 4 Claims ABSTRACT OF THE DISCLOSURE A variable and adjustable shock absorber for crutches comprising in combination: a cushion tube; a piston tube adapted to reciprocate in said cushion tube; and end plug fixed in the upper end of said cushion tube; spring means adapted to maintain said cushion tube and said piston tube in a normally extended position; a piston xed to the upper end of said piston tube; adjustment means in said cushion tube to effect various shock absorbing characteristics between said cushion tube and said piston tube; selection knob means associated with said adjustment means at one end, the other end of said knob means extending through said end plug and externally of said cushion tube; lock-nut means to fix said knob means at a selected position; side rails fixed longitudinally with respect to said cushion tube; an adjusting space on each side of said cushion tube formed by said rails and said cushion tube; and an adjustment bar in each of said adjusting spaces to x said absorber to a clutch.

This application is a continuation-in-part of my copending application Ser. No. 640505 3, tiled May 22, 1967, and now abandoned.

This invention relates to new and useful improvements in shock absorbers for crutches.

OBJECTS It is an object of this invention to provide structure whereby very slight overall height variations of the crutch may be effected.

It is an object of this invention to provide structure whereby one crutch may be used by many various invalids, each having a different weight.

It is an object of this invention to provide structure whereby variations in the cushion eifect may be made while the crutch user walks.

It is an object of this invention to provide external structure whereby the cushion effect may be shut off entirely when the user desires to climb stairs and then to be re-set when normally walking.

These and other objects will become obvious from the drawings in which:

DRAWINGS FIGURE 1 shows the hydraulic or -first species;

FIGURE 2 shows the pneumatic or second species;

lFIGURE 3 shows the mechanical or third species;

FIGURE 4 shows a partial cross section of the absorber tube and crutch attachment;

FIGURE 5 shows a bifurcated composite of actual crutch connections;

FIGURE 6 shows the retaining pin relationship.

FIGURE 1 FIGURE 1 discloses a cushion tube l1 and projecting therefrom a foot tube 2 adapted to partially reciprocate in cushion tube 1. Cushion tube 1 is partially closed at its upper end by an end plug 3 being press-fit therein. The space between the lower internal surface of cushion tube ice 1 and the upper end of foot tube 2 where reciprocation takes place is sealed off by means of an O-ring 4. At the upper end of foot tube 2 is situated a piston 5 which has a reduced section 6 projecting into the end of foot tube 2 and which piston 5 further has piston rings 7. The internal space of foot tube 2 further provides for a coil spring 8 which at its upper end bears against guide pin 9 which, in turn abuts against a resilient recoil stop 11. Guide pin 9 extends through guide groove 10 in the wall of piston tube 2 and into a bore in the wall of cushion tube 1 so that guide pin 9 is motionless with respect t-o piston tube 2 and that under the renitent pressure of coil spring V8 the cushion tube 1 and the piston tube 2 are in a normally extended relationship. At the bottom of piston tube 2 is a tip plug 12 held therein by means of pin 13. A neoprene dust cover '15 adapted to breathe and having convolutions thereon fits around the end of piston tube 2, over the end of cushion tube 1, over collar 16, and under ring clamp 17. Over the end of the piston tube 2, tip plug 12, and dust cover 15 fits the usual rubber tip 14. In the inside of cushion tube 1 at about the midway point is fixed a valve adjusting means 18 comprising an inlet port 21 which connects oil compression chamber 38 to the oil reserve chamber 28. The ow of oil or any suitable liquid from compression chamber 38 to reserve chamber 28 is effectedv by the influence of piston tube 2 being under the pressure of the walking step and is controlled by the needle 33 selectively restricting its complementary counter bore 22. The oil reserve chamber 28 is not entirely full of oil and therefore has a certain amount of air contained therein, which air must be provided with an intake port 29 which is open on the released step of the crutch and which port 29 is closed on the walk step or compressi-on stroke by means of a neoprene ball 30 which is held in intake port 29 in a closed position by means of coil spring 31, which, in turn, is retained by a bored set screw held in place by threads 32. This valve means allows air intake and prevents air lock in the reserve chamber thereby increasing the recoil action. The expansion of the air under cornpression in oil reserve chamber 28 and the recoil of spring 8 together effect a compression suction situation which causes the oil in reserve chamber 28 to return to the oil compression chamber 38 through return port 27. This compression-suction inter-relationship causes a dampening of the overall cushion effect. Needle 33 is actuated by turning selection knob 36 which is externally of the cushion tube 1 and extends upwardly to allow the crutch user to determine and adjust the cushion effect while he walks. This adjustment is selected and set by means of the needle valve stem 34 having threads 35 at the point where it extends through end plug 3 and can be locked in place by tightening the knurled lock nut 37. AnhO-ring 34A around needle valve stem 34 is to prevent) leakage. Upon release of the oil pressure as the invalid makes a step the oil is drawn back into the compression chamber 38 fro-m the oil reserve chamber through the return port 27 which is closed only on the compression stroke by means of ball-check valve 23 being disposed in a counter bore 24 which ball valve 23 is held in place by a half moon snap spring 25 which in Aturn is retained in recess 26. Fixed longitudinally along oppositely disposed sides of cushion tube 1 is the side rails 20 which provide a longitudinally extending and height adjusting bar space 39 and abutment surface 19. (See FIGS. 4 and 5.)

FIGURE 2 FIGURE 2 discloses the second or pneumatic modification which comprises a cushion tube 40 Iand a piston tube 41 adapted to reciprocate therein. The upper end of cushion tube 40 is partially closed off by means of an end plug 42 which has a 4breather port `4 open to the atmosphere. At the lower end of cushion tube 40, Where the piston tube 41 extends outwardly therefrom, there is `an O-ring `43 which acts las a sliding surface guide and further as a cleaning device and to -prevent scraping. At the upper end of piston tube 41 is found a piston 44 having a reduced section 45 extending in and fixed into the bore of piston tube 41. Piston 44 has a plurality of rings 46 'which act as piston rings normally do and further a piston bore 48 and a ball valve 49 situated in said piston bore 48 which ball valve 49 is held in a normally closed position by means of coil spring 50 which, in turn, is held in place by a bored set-screw held in position by threads 67. Extending longitudinally of the piston tube 41 is a guide groove 52 and a guide pin 51 extending through said guide groove 52 into a bore in the wall of the cushion tube 40 so as to be fixed relative to cushion tube 40. Between said guide pin 51 and said piston 44 is located a recoil stop washer 53. The cushion tube 40 and the piston tube 41 are held in a normally extended position by means of coil spring 47 bearing against the foot of the piston tube 41 and the guide pin 51 so as to effect the normally extended relationship which, under the pressure of walking will cause piston tube 41 to recess into c-ushion tube `40. There is fixed in the internal walls of cushion tube 40 a valve adjusting means 55 having a needle valve port 56 and an associated needle 57 adapted to fit snugly into a complementary counter bore 69 in the top of valve adjusting means 55 thereby providing a restriction for the needle valve port 56. The needle 57 is at the lower end of the needle valve stem 58 which extends through the end plug 42 and is adjustable with respect to said end plug 42 by means of threads 59. Situated lon the end of needle valve stem 58 is a selection knob 60 for selectively setting needle 57 of the valve adjusting means 55. Where the selection knob 60 has been activated to the proper setting, it can be fixed in that position by means of the knurled lock-nut 61. End plug 42 further has an end plug bore 64 through which the needle valve stern 58 extends and which bore further provides an O-ring 65 surrounding said needle valve stem 58 to prevent blow-by. Extending longitudinally and oppositely disposed with respect to each other is a pair of side rails `62 fixed to the cushion tube 40 for an abutment surface 63, later to be described. The 4abutment surface 63 further provides height adjusting bar space 68. At the lower end of the piston tube `41 is found a tip plug 66 over which can be provided the usual rubber tip.

FIGURE 3 FIGURE 3 shows the mechanical species of the invention comprising a cushion tube 70 and a piston tube 71 adapted to reciprocate therein. One upper end of cushion tube 70 is partially closed by means of an end plug 72. At the top end of piston tube 71 is situated a piston 73 having O-rings 74 thereon. Above the piston 73 is located compression air space 76 and above the compression space 76 is found an adjusting means 78 having a plurality of O-rings 79 thereon to engage the internal wall of cushion tube 70. Compression air space 76 is additionally occupied by coil spring 75 which keeps cushion tube 70 and piston tube 71 in a normally extended position. The resistance of spring 75 is determined by raising or lowering adjusting means 78 by turning selection knob 81 which acts through threaded stem 80, freely rotating stem 82 and ball bearing `83 to set the longitudinal position of adjusting means 78, which, when determined, can be fixed by tightening up the knurled locknut '86 against the neoprene washer 96 and thereby the end plug 72. Above the adjusting means 78 is breather air space 84 and la breather port 85 in the wall of cushion tube 70. In the compression air space 75 is a breather port 77. Where the piston tube 71 extends from the cushion tube 70 there is situated an O-ring 88 which acts as a seal and Wiper. In the wall surface of piston tube 71 there is :a longitudinally extending guide groove 89 having a guide pin 91 extending therethrough fand into a hole in the wall of cushion tube 70 whereby the piston tube, under pressure, will rise the distance of the guide groove 89. A recoil stop in the form of -a -Washer is provided to make the recoil impact smoother. Side rails 92 are provided to facilitate the attaching of the shock absorber to a crutch by ymeans of an abutment surface 93 and the height adjustment space 95. There is fur-ther provided a tip plug 94 over which the usual rubber tip is forced.

FIGURE 4 FIGURE 4 shows yan isometric view of the cushion tubes 1, 40, 70, the side rails 20, 62, 92, the associated abutment surfaces 19, 63, 93 and the longitudinally extending groove formed thereby and the height `adjustment bar 101. Extending through the adjustment bar 101 is bolt 102 and wing nut 103 fastening means all f-or adjustably fixing the shock absorber to a crutch.

FIGURE 5 FIGURE 5 discloses la divided composite of a cross sectional view of the structure necessary to fix the shock absorber tube to the present crutch on the left of the center line and to a metallic crutch on the right of the center line. There is shown the cushion tube 1, 40, 70, the side rails 20, 62, 92, the abutment surfaces 19, 63, 93 and the adjusting bar spaces 39, 68, 95, and the adjusting bar 101. The shock absorber is adjustably fixed to wood crutch 106 by means of bolt 102 and Wing nut 103. The Shock absorber is adjustably fixed to the metallic crutch form 105 by means of screw 104 and adjusting bar 101.

FIGURE 6 FIGURE 6 shows an enlarged View of the relationship of the guide pin 9, 51, 91 having an assembly bore 9A therein to receive a tool to facilitate the assembly thereof through a bore in the wall of cushion tube 1, 40, 70 and the guide groove 10, 52, 89 in the wall of piston tube 2, 41, 71. The piston tube 2, 41, 71 houses the coil spring 8, 47 which coil spring 8, 47 Ibears against the guide pin 9, 51, 91 to keep the guide pin 9, 51, 91 abutting against the top of the bore in the wall of cushion tube 1, 40, 70 so that the shoulders of guide pin 9, 51, 91 will insure that guide pin 9, 51, 91, under constant pressure, will be retained in place. The reduced section 6, 45, 73 of the piston that recesses into the piston tube 2, 41, 71 rests on the top of a resilient recoil stop 11, 53, 90 and the guide pin 9, 51, 91, under pressure, bears against the bottom of the recoil stop 11, 53, 90.

1ILlaving thus disclosed and described my invention, I c aim:

1. variable and adjustable shock absorber for crutches comprising in combination:

a cushion tube;

a piston tube closed at its lower end, the upper end adapted to reciprocate in said cushion tube;

an etrJid plug fixed in the upper end of said cushion tu e;

spring means adapted to maintain said cushion tube and said piston tube in a normally extended position;

a piston fixed to the upper end of said piston tube;

adjustment means in said cushion tube to effect various shock absorbing characteristics between said cushion tube and said piston tube;

selection knob means associated with said adjustment means at one end, the other end of said knob means extending externally of said cushion tube through said end plug;

lock-nut means to retain said selection knob means at a fixed position;

side rails fixed longitudinally Iwith respect to said cushion tube;

an adjusting space on each side of said cushion tube formed by said rails and said cushion tube; and

an adjustment bar in each of said adjusting spaces adapted to x said shock absorber to a crutch.

2. A shock absorber as in claim 1 wherein there is provided an oil compression chamber (38) between said piston (5) and said adjustment means (18); an oil reservoir chamber (28) between said adjustment means and said end plug (3); and wherein said adjustment means is a needle valve means (33, 22) adapted to control the flow of a hydraulic medium; and said end plug has a one-way air intake port (3).

3. A shock absorber as in claim 1 wherein said adjustment means (55) is a needle valve ('56, 57); wherein said end plug (42) is open to the atmosphere (54); wherein said piston (44) is provided with a ball valve means (49).

4. A shock absorber as in claim 1 wherein said selection knob means (81) effects renitent pressure in said spring means (75) 'by extending said adjusting means (78) in a breather air space (84; said air being vented to the atmosphere by means of a breather port (85); Isaid spring means situated in a compression air space (76) between said piston (73) and said adjusting means; said compression air space being vented to the atmosphere by means of a breather port (77).

References Cited UNITED STATES PATENTS 665,439 1/1901 Hough 135--60 834,205 10/1906 Jones 13S-60 X 1,336,844 4/ 1920 Klousnitzer 135-60 1,464,057 8/1923 Bell 135-61 1,753,065 4/1930 Payne 135-60 2,398,534 4/1946 Klousnitzer et al. 135-60 2,426,594 9/1947 Buell et al. 135-61 2,478,667 8/ 1949 Shellhouse et al. 13S-61 X 2,856,943 10/ 1958 Sparlin 13S-49 3,304,946 2/ 1960 Lutes 135--50 FOREIGN PATENTS 880,960 10/ 1961 Great Britain.

PETER M. CAUN, Primary Examiner U.S. Cl. X.R. 13S-60, 61

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