Crutch tip construction

H. C. McGOWAN

499

CRUTCH TIP CONSTRUCTION

Filed March 17, 1945

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Henr-i C./47Govran.

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Patented Apr. 2, 1946

2,397,499

UNITED STATES PATENT OFFICE

2,397,499

CRUTCH TIP CONSTRUCTION

Henri C. McGowan, Augusta, Ga.

Application March 17, 1945, Serial No. 583,308 .

(Cl. 135—53)

Figure 4 is a horizontal sectional view taken on the line IV—TV of Figure 2;

Figure 5 is a fragmentary sectional view similar to Figure 2, but illustrating an anti-friction member included in the structure;

Figure 6 is a fragmentary sectional view similar to Figure 2, but illustrating a somewhat different securing structure therein; and

Figure 7 is a view similar to Figure 6, but illustrating still another securing structure.

The crutch tip construction of this invention comprises a tube 10 . having an upper portion secured to the lower end II of an upright member of a crutch, as by bolts 12. The tube 10 is provided with a stop member for the crutch portion II. In this instance, the stop member is illustrated as taking the form of a bolt 13 extending through the tube 10. The stop member is desirable in cases where the tip construction is provided separately from the crutch and may be applied to the crutch by an inexperienced person, and assures that the crutch portion 11 will not extend too far into the tube 10 to interfere with the operation of the cushioning means.

A tubular member with a closed bottom end, which may be described as the cup 14 is provided in telescoped relation with the tube 10. The cup 14 has an outer diameter such as to fit snugly within the tube 10 and yet have free movement therein. A block 15 of wood, synthetic plastic, metal, or the like having an axial bore therethrough. is disposed in the cup 14. A bolt 16 extends through the bore in the block IS and a central· aperture in the bottom of the cup 14. The end of the bolt projecting through the bottom of the cup 14 is threaded to receive a nut IT, and the upper end of the bolt is provided with a head 16a. The bolt extends from the bottom of the cup 14 to a point somewhat below the crutch portion 11, or the stop member 13.

In order to secure the cup 14 to the tube 10, a sleeve 18 is provided within the tube 10 and spaced a desired distance above the open end of the cup 14 when the cup is in its outermost position relative to the tube. The sleeve 18 is secured in position in any desired manner, as for example by means of bolts 19. An apertured disk or washer 20 is seated on the upper end of the sleeve 19, and a similar washer 21 is provided to seat 50 against the lower end of the sleeve. The bolt 16 extends through the washers 20 and 21, the head 16a thereof resting on the upper surface of the washer 20.

As shown in Figure 2, a spring 22 is disposed between the washer 21 and the block 15, and

Claims.

This invention relates to a crutch tip construction, and particularly to a crutch tip including shock absorbing means and providing a swivel connection between the crutch and the tip.

Discomfort and pain are suffered by users of crutches by reason of the jolting and jarring resulting from the impact of the crutch tip on floors, pavements, and other similar hard surfaces. There is also a constant danger of slipping of the crutch tip due to a partial rotation 10 of the crutch as it is moved in use. Even though the crutch tip may be firmly planted on a surface, the partial rotation of the crutch may turn or twist the tip out of its firm engagement with the surface and cause it to slip or slide, and possibly cause injury to the user. The crutch tip construction of this invention provides shock absorbing means to cushion the impact of the crutch on the ground or other surface, and also provides a connection between the tip and the body of the crutch which permits relative rotation therebetween so that rotation of the crutch is not imparted to the tip. The invention thus overcomes the difficulties which have been pointed out, and contributes to the safety and comfort of persons using crutches.

It is an object of this invention to provide a crutch tip construction cushioning impact of the crutch.

It is another object of the invention to provide a crutch tip construction having a swiveled connection with the crutch.

It is a further object of the invention to provide shock absorbing means swivelingly connected to a crutch.

It is also an object of the invention to provide a shock absorbing crutch tip which may be adjusted to accommodate different loads.

It is an additional object of the invention to provide a crutch tip having telescoped elements slidable longitudinally relative to each other and rotatable relatively to each other.

Other and further objects and advantages of the present invention will be apparent to those skilled in the art from the following description and the appended drawing.

In the drawing: .

Figure 1 is a fragmentary elevational view of a crutch tip construction embodying this invention;

Figure 2 is a vertical sectional view taken on the line II—H of Figure 1, with parts in elevation;

Figure 3 is a view similar to Figure 2, but showing a slightly modified form of the invention; I

3.0 urges the block 15 and therefore the cup 14 outwardly of the tube 10. A washer 23 may be disposed on the upper end of the block 15. A conventional crutch cushioning tip 24 of rubber or the like is applied to the lower or closed end of the cup 14. The structure shown in Figure 3 is identical with that shown in Figure 2, except for the provision of a block 25 of rubber or similarly resilient material surrounding the bolt. 16, in place of the 10 spring 22 illustrated in Figure 2. The block 25 is preferably cylindrical, and has a diameter smaller than the inner diameter of the cup 14, to allow for radial expansion when compressed axially. 15

The cup 14 and bolt 16, together with.the block and the spring 22 or the block 25, may rotate freely within the tube 10,· or in other words the tube 10 may rotate freely about the cup 14 and bolt 16. A swivel connection between the mem- ₂₀bers is thus provided. By this construction, therefore, the cushioning tip 24 does not have its i contactwith the ground or other surf ace affected by rotation of the upper part of the crutch which occurs in use of the crutch. There is thus no _2gdanger of the crutch tip slipping by reason of being twisted or turned Mong With the upper part of the crutch as the crutch moves in use. The provision of the spring 22 dr resilient block 25 in connection with the cup 14 provides a shock absorbing means for the crutch to cushion, the impact of the crutch on the ground or other surface. As the crutch is brought into contact with the ground and the weight of the body is appplied thereto; the tube 10 moves downwardly- about the ₃₃cup 14 against the yielding resistance of the spring 22 or resilient block 25, until the washer 21 comes into contact with the upper end of the cup 14. The weight of the User of the crutch is them transmitted directly through the tube. 10., sleeve 18, and cup 14 to the ground, these elements being then in substantially rigid and fixed relation. Thus, When the full weight of the user is borne by the crutch, it is substantially unyielding and provides the necessary stability to carry 45 the user safely. The space between the bolt head i 6 a and the crutch portion It or stop member 13 is at least equal to the space between the washer 21 and the open end of the cup 14: in its outermost position. ⁷ 50

The block 15 may be provided of any desired length or height to compress the spring 22 or the resilient block 25 to give* it* a force; corresponding to the weight of the user of the crutch. The same spring may thus be adapted to properly cushion the cruteh; be the crutch employed by a heavy or a light person, by providing a longer or shorter block 15, respectively. It will be obvious that if desired· the single block 15 may be replaced by a plurality of blocks of varying lengths or thick- ₆₀nesses so that the initial pressure of the spring 2-2 or resilient block 25 may be adjusted as desired by the insertion, removal, or substitution of one or more blocks. .

The spring pressure may also be adjusted by ₆₃the nut 17, though only to-a limited extent,*as will be obvious. The. adjustment by means of the nut ί 7, however, may be employed together with the adjustment possible* by* variation of the size of the blobk 15 to givre the exact adjustment of the spring 22 or resilient hlbek 25 that: may be desired.

Regardless of the particular length of the block

15, the distance between- the washer 21 sand the Upper- end of the cup ^;l-4 in- itfstextended¹ condition:

2,397,499 is constant, so that the amount of movement of the tube 10 on the cup 14 is the same, and the crutch may therefore be made of proper size to fit the height of the user. Furthermore, this distance or movement remains the same for the same user even though the adjustment of the spring or resilient block is changed by the user, so that it is not necessary for him to become accustomed to a new degree of movement in case of such change. A distance of the order of one inch is ample to provide proper cushioning action and does not occasion an excessive movement.

If desired, the swivel connection between the tube 10 and the cup 14 and bolt 16 may be made freer and easier by the provision of anti-friction means, such as the ball bearing 26 illustrated in Figure 5 as disposed between the washer 21 and the bottom of the sleeve 18. Obviously, such antifriction means might be provided in connection with the washer 20 or the washer 23, if desired.

Means other than the sleeve 18 may he employed for securing the cup-14 to· the tube* 10, In Figure 6, far example, this means is illustrated as circumferential projections or flanges 27 on the interior of the tube 10 formed by grooving or collapsing the tube radially inwardly. The washers 20 and 21 seat against the flanges 27 in the. same manner as against the ends of the sleeve 18 in the construction as previously described. Only one inner flange 2.7 might of course be provided, and the washers 20 and 21 seated against the opposite axial bases thereof. In Figure 7, the securing means is illustrated as a partition. 28 closing the tube 10 except for a central aperture to accommodate the bolt 16. In this case, the washers 20 and 21 are unnecessary, the bolt head 16a resting on the upper face of the partition 28 and the spring 22 or resilient block 25 bearing on the lower face thereof. The partition28 may be provided in any of several ways. An apertured disk may be welded or brazed to the interior surface ofthe tube 10, orthe tube may he drawn with the partition integrally formed therein,, or the partition may be secured in the tube l>0 between inner circumferential ledges or projections such as the flanges 27 shown in Figure 6.. * .

Ftom the foregoing, description,, it. will. be. evident that the bolt 16 serves both to secure the elements of the shock, absorbing or cushioning means together,; and- also secures, this means, to the telescoping tube 10 in* freely movable relation therewith.. The :crutch may rotate about the cup' 1:4 at 'the same· time that it moves downwardly, and simultaneously the downward movement is* cushioned: by the resilient means- 22 or -25.. When, the -limit, of relative .movement has been reached, as the full weight- of. the user is applied to. the crutch*,, the, crutch acts as a substantially rigid’ and -solid,unit- to carry the load with utmost stability.. - This stability is of great importance to the confidence and peace of mind of the: user. The- effective resistance of the resilient: means to the ’ compression, due to. the weight of the user -may be- adjusted - as;· desired without requiring a substitution-of·, the* resilient, means, or a disassembly of, the entire- structure. The telescoping: movement.of the crutch is maintained‘constant, and is* relatively·· slight, so- that '70 the- crutch User need: not. constantly anticipate and attempt to estimate variations'in. movement of the crutch. The invention thus provides a crutch which, frees· the user of bothphysicalsand mental discomfort, effort, and* pain.-andc greatly increases the safety of the crutch in use. - · _:

2.397,499

The invention is not limited to crutches, since it may be applied to canes and walking sticks, and may be employed in other structures in which a swivel connection of a resilient cushioning means is desired.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.