US2194116A - Artificial leg connection - Google Patents

Description

March 19, 1940.. s. E. FORSTER ARTIFICIAL LEG CONNECTION Filed Jan. 16, 1959 INVENTO Guy E Forsfer Patented Mar. 19, 1940 UNITED STATES PATENT OFFICE I ARTIFICIAL LEG CONNECTION I Guy E. Forster, Cincinnati, Ohio Application January 16, 1939, Serial No. 251,057

t1" Y 4 Claims.

The invention has reference to an artificial limb connection, and particularly to the improvement of the connection between an upper-leg stump socket part and a body band, belt, or' other "5 suspension means for the socket part.

An object of the invention is to provide improvements in an artificial limb structure whereby the breakage of parts, wear, noise, and frequent servicing are reduced to a minimum, or obviated entirely.

Another object is to greatly facilitate the wearers efforts to simulate natural leg and body movements, and to accomplish this by meansv of a simpler, rather than a more complex, alteration in construction.

Another object of the invention is the provision of improved means of the character stated, whereby much of the discomfort and inconvenience of wearing an artificial limb are effectively minimized, especially by eliminating chafing, pinching and distortion of the wearer's body in the various body postures and movements.

A further object of the invention is to greatly simplify and reduce the cost of artificial limb structures, as well as the cost and inconvenience of frequent servicing and adjustments. The tightening and lubricating of the parts have been eliminated entirely.

The foregoing and other objects are attained 5 by the means described herein and disclosed in the accompanying drawing, in which:

Fig. 1 is a side elevational View showing the invention applied to the body of a wearer in standing position. v

Fig. 2 is a view showing the relationship of the device to the wearers body when in a sitting or stooped position.

Figs. 3 and 4 are elevational views showing the relationship of the parts when the trunk of the body is turned or pivoted to the right, and to the left, respectively.

Fig. 5 is an enlarged cross-sectional view taken on line 55 of Fig. 3. 1 Fig. 6 is a fragmental perspective view of '4 limb connection means of the invention.

the

It has been customary and usual in the past,

to support an artificial limb part, such as a thigh section 8, from a belt, band or other body harness member applied to the body in the region of the hips, waist, or pelvic region; An

sented various problems that have been more or less a source of annoyance" and expense to the person who was required to make use of an artificial limb. For example, the use of metal pivots and links resulted in squeaks and rattles due to the parts becoming worn and loose, and when such conditions occurred it was necessary for the user to have the parts tightened or replaced. Another inconvenience was that the device required frequent lubrication, and this of course resulted in soiling the clothing. Metal pivots and links in the limb structure had a tendency also to chafe and pinch the Wearers body under certain conditions, and would not ordinarily permit the freedom of movement that was considered desirable but unattainable in an artificial limb structure.

Prior to the present invention, various improvements were made for the purpose of en- 'hancing the flexibility of use of the artificial limb, but at the expense of reducing the qualities of durability and freedom from breakage and frequent servicing. Such improvements embraced the use of leather straps for connecting the limb part to a body harness, and when such straps were anchored to prevent pivoting nove ment thereof at the body harness, strains were imposed across the width of the straps tending to stretch one side edge and compress the other side edge, so that the material of the straps was soon torn and required replacement. instances, a plurality of flexible straps were used, the lower ends of which were secured at spaced intervals along the top of the artificial limb part, but such constructions were objectionable in that some of the straps were tensioned .while the others were buckled up in an objectionable manner when the wearer assumed seated or stooped positions. Both the tensioned and the buckled straps resulted in discomfort to the wearers body in the region of the hips and thighs.

The various principal objections above referred'to, as well as other minor objections not worthy of mention, have been efiectively over-' come by means of theimproved construction of artificial limb connection herein disclosed.

With reference to the accompanying drawing, 8 indicates the thigh part of an artificial limb, and I0 and I2 indicate the lower leg and foot portions. These parts 8, l0, and I2 are suitably .reticulatedor hinged in accordance with com- In some .3

mon practice. The means usually employed for control of the parts I and I2 while walking, have been omitted from the disclosure for the reason that they form no essential part of the present invention. The wearers leg stump is indicated at I3 and as will be understood, same is suitably supported within the hollow socket portion of the thigh part, the usual padding being employed for the wearers comfort.

The harness part 9 may be of leather, fabric, or other suitable material properly padded and shaped to fit either the waist or the pelvic region of the wearers body. The harness is adapted to support a curved brace or strap 2! of rigid material, which may be light weight metal or an equivalent thereof. The brace 2| may be fixed to the harness in any suitable manner, such as by means of rivets, bolts, or the like I4. The brace is adapted to carry an adjustable pressure clamp part IS, the exact nature of which will be treated hereinafter.

To the outer face of the thigh part 8, there is fixed a base plate 22 which likewise has an adjustable clamp part II. The base plate may be screwed or otherwise fixed to the thigh element 8, as indicated by the drawing.

In accordance with the invention, the connection between the harness and the base plate of the thigh part, is effected by means of a bar l8 molded or otherwise shaped from resilient soft rubber or any rubber like material that may be considered an equivalent of resilient soft rubber for the purpose of this disclosure. It is important that the bar l8 be of substantial thickness, such as to impart thereto the characteristics of flexibility in all directions laterally, together with limited stretchability and high though yielding resistance to lengthwise compressibility. T0 attain these characteristics, the bar of resilient soft rubber may be made cylindrical or slightly oval in cross section, with a mean diameter approximating 1", more or less. The bar |8 may be several inches in length but the length thereof will be determined by the build or physique of the wearer of the artificial limb.

In the preferred form of the invention, the soft rubber bar E8 is pendant substantially vertical from the harness, and only one such bar is employed, by preference. The advantage of this is readily appreciated when referring to Figs. 2, 3, and 4, which show the ease with which the soft rubber bar or connector will accommodate itself to movements of the wearers trunk relative to the artificial leg part 8. It will be noted from Fig. 2, that the soft rubber connector accommodates itself to whatever position is required for enabling the wearer to sit or stoop, or otherwise bend his body below the abdomen. It should be noted particularlythatnostrains or cutting tendencies will be experienced by the wearer exemplified by Fig. 2, such as would be bound to occur with the use of strap connectors that would be drawn taut or would buckle under the same conditions.

With further reference to Fig. 2, it is important to note that there is nothing to prevent the wearer from swinging his artificial limb sidewise in a horizontal plane with absolute freedom to do so. This is a movement which cannot be accomplished where the limb structure is constituted of pivoted metallic parts.

Fig. 3 shows a desired distorted condition of the soft rubber bar connector, resulting from the wearer turning or pivoting the trunk of his body to the right, without changing the position of his artificial left leg. It should be noted that the effort to so pivot the body will be no more than is required of a person having a natural left leg, and the natural tendency of the resilient bar is to return the trunk to normal position relative to the thigh portion of the leg, just as the muscles of a natural leg would operate. The same advantages are noted when the wearers trunk is turned or pivoted to the left, without shifting the movements of the artificial left leg.

Due to the fact that the unusual thickness of the soft rubber connecting bar imparts thereto a yielding resistance compressible lengthwise, the bar acts as a shock absorber for upward forces resulting from contact of the foot upon the pavement with each successive step of the walking function. For the same reason, lengthwise stretchability of the connecting bar is quite limited, so that there may be no tendency for the leg stump to move in the leg socket and thereby chafe the skin of the leg stump. In other words, there is just suflicient pressure between the leg stump and the artificial leg socket to furnish a sensation of comfort, as the pressure upon the stump resulting from walking, is alternately relieved without actual relative movement between the leg stump and the socket of the artificial limb part Another advantage incident to the use of the resilient soft rubber like material in a connecting bar of substantial proportions as described, is the ease with which the upper and lower portions H3 and 20 thereof may be secured to the brace 2| and plate 22, respectively. As herein disclosed, it is necessary only to squeeze the opposite ends of the soft rubber bar tightly against the parts and 22 by means of simple clamping elements l and I6 so that said ends cannot shift or move, thereby obviating wear at the anchorages, and eliminating all need for lubrication and subsequent tightening. It will be evident, of course, that the structure cannot possibly develop squeaks or rattles at any location.

The clamping elements I5 and I6 may be identical. and each may comprise simply a metallic rigid strap having perforate ears 23 and 24 and a curved intermediate portion adapted to tightly squeeze or pinch the end of the soft rubber bar to ensure absolute fixation thereof. It is considered preferable, though not absolutely necessary to furnish screw threaded means for drawing the clamp part tightly upon the end portion of the soft rubber bar, and to this end, the perforations of the ears 23 and 24 may be caused to register with similar perforations in the brace 2|, thereby enabling the introduction of a screw 25 whose shank may threadedly engage a nut 28 at the back of the brace. The head of the screw, as well as a portion of the nut, may be counter-sunk in the metallic parts to avoid objectionable projecting parts, and to enhance the appearance of the device in general. The nut 26 where exposed at the back of the brace 2|, may be of hexagon or other shape so as to accommodate a wrench if and when required during application of the clamp part. As clearly indicated in Fig. 5, the upper and lower edges of the clamp parts may be flared or rounded so as to eliminate any possibility of cutting into or wearing away of the areas of the soft rubber bar adjacent to the clamping areas. In the less expensive forms of the device, the screw arrangement 25-26 may be replaced by rivets or other fastening means, if desired.

It is noteworthy that the rigid clamping of the opposite'end portions of the bar does not interfere with twisting of the soft rubber bar axially, to

enable the wearer to point the toe of the artificial limb either inwardly or outwardly and, in fact, the

wearer may accomplish without undue effort, any leg movement that he may be wishful or able to accomplish by skillful control of the leg stump. Such accomplishments are not readily permissible when the artificial limb is supported by means of metallic links and pivots, or straps that tightly tension or buckle in the various natural positions I assumed by the wearers body.

As previously stated, the invention'is intended to comprehend the use of rubber substitutes and rubber compositions in formation of the bar l8, and the cross-sectional shape of the rubber bar is immaterial so long as the thickness thereof .is substantial in comparison with the thickness of an ordinary leather strap with relation to its width. Various other modifications and changes may be made in the structural details of the device, within the scope of-, the appended claims,

without departing from the spirit of the invention.

I claim:

1. In an artificial limb, structure, the combination of a thigh part, and a suspension means lengthwise, said bar having upper and lower portions fixed, respectively, to the body harness and the thigh part of theartificial limb structure in an upright position.

2. In an artificial limb bination of a thigh part, and a suspension means therefor comprising a harness adapted to be structure, the comcarriedby the body of a wearer, and a connector between the thigh part and the harness, said connector comprising a bar of resilient soft rubber material of a substantial thickness such as to impart thereto the characteristics of flexibility in all directions laterally, together with limited stretchability and high. though yielding resistance to compressibility lengthwise, saidbar having opposite resilient laterally compressible end portions, and-means on the harness and the thigh part for clampingsaid compressible end portions securely against movement and resultant wear and noise, thereby imposing upon the intermediate portion of the bar substantially all the burden of flexion due to use of the artificial limb.

3. An assembly for attachment to an artificial limb, which assembly comprises a bar of flexible and resilient material of a substantial thickness such as to impart thereto the characteristics of flexibility in all directions laterally, together with limited stretchability and high though yielding resistance to lengthwise compressibility, said bar having opposite ends, a body brace of substantially rigid material and means thereon for tightly clamping one 'end of the bar against relative movement, a base plate for attachment to a limb, and means for tightly clamping the other end of the bar in fixed relation to the base plate.

4. An assembly for attachment to an artificial limb, which assembly comprises abar of flexible and resilient material of a substantial thickness 7 such as to impart thereto the characteristics of flexibility in all directions laterally, together with limited stretchability andhigh though yielding resistance to lengthwise compressibility, said bar having opposite ends, a body brace and means thereon for tightly clamping one-end of the bar against relative movement, and means for securing the other end of the bar in fixed relation to an artificial leg.

GU OR ER.

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