US2379538A - Joint for leg supports and artificial limbs in general - Google Patents

Description

ERAL

1945- i M. MEIER I -IQFER JOINTS FOR LEG SUPPORTS AND ARTIFICIAL L IMBS IN GEN Filed Dec. 6, 1943 Patented July 3, 1945 JOINT FOR LEG sUPPoRr-sANnfAn'rIFioiAn p v f Max Meierhofer, Erlenbach', urich,

. Switzerland 1.

. Application December 6, 1943,

erial No. 513,110. g

In Switzerland September-$1 1 Claim. (01. 2874101 v;

This invention relates to joints for'leg sup ports and artificial limbs in general.

In the joint forleg supports and artificial limbs in general, according to the present invention, in one of two joint parts, that are interconnected tation between the parts 2 and 4. This range by pivot means at mutually overlapping portions I said arts, a, stop means is provided which is fitende to cooperate with the other Jo nt part for limiting the angular range of relative rotational movement between said parts, the clearance formed by effectof this angular range being covered by a cover plate secured to one of said parts.

This arrangement serves the purpose of preventing a garment pulled over the jo nt, for example a stocking, from being caught in the Jomt and thus damaged or torn,

A well known drawback of the conventional open gap joints in leg supports and artificial limbs in general consists in that garments of the wearer easily tangle with this joint so as to get caught therein and are thus liable to be damaged.

The joint forming the object of the present invention is illustrated in the accompanying drawing, by way of example only, in the form of a leg support for use by a lame person, in wh1ch Fig. 1 shows a side elevation of the lower part of the leg support; I

Fig. 2 is a similar elevational view of the lower part of the legsupport an a larger scale;

Fig. 3 is a view as seen at right angles to that showninFig.2;

Fig. 4 is a sectional view corresponding to- Fig. 5 is a view similar to that shown in Fig. 2 partly in section;

Fig. 6 shows a side elevation of a modified cover plate;

Fig. 7 is a view as seen at right angles to that shown in Fig.6; v I

Fig. 8 is a sectional view corresponding to Fig. 7, and

Fig. 9 shows a cross section on the inFig. 6. o

Referring to Fig. 1 of the drawing, the numeral l designates the foot portion of the support and 2 refers to the ankle portion upstanding from the foot portion. To the ankle portion 2 a shank rail line IX-IX '4 is pivotally connected by means of a tap bolt 3, to the upper portion of which rail in turn a thigh rail (not shown) is pivoted. The lower end portion of the shank rail 4 is provided with two symmetrical oblique end faces 5 which are directed towards the center of the tap bolt 3 in symmetrical relation to each other and which by cooperation tatntwb' respectiveoblique faces 6 ,on a stop plate .1 immovably connectedhto the ankle portion 2. define the-angularrange. of relative roamounts in the present instance, for example, to about 30.

The stop plate 1 is immovably secured to the part 2 by means of acountersunk rivet 8 andtwo countersunk pins 9. The connecting rivet 8 and the bolt 3 serve for securing in position a cover plate ID. This plate is exteriorly disposed at the point of junction of the parts 2 and 4 and bridges the gap existing between the oblique faces 5 and 6 by which means appropriate protection against the stocking pulled over the support being caught in thisgap is provided. The parts I, 2, 4 and I0 consist of a light metal, advantageously anticorplate In is covered towards the'outsid odal, which may be provided with a layer of nitrocellulose varnish or enamel as a coating against the corroding effect of perspiration.

0n the tap bolt 3 connecting the joint parts 2, 4 with each other a bush I2 is carried which is advantageously made of graphite bronze or fibre. On the ends of the bush l2 for receiving the shank rail 4bearing discs l3 made of thin sheet steel are placed and inserted in lateral recesses in the shank rail 4. of friction between the side surfaces of the parts 2, 4 and I0 can be reduced to such an extent as to be practically negligible and no lubrication need be provided for the joint in which way soiling of the stocking, which hitherto had been unavoidable due to the necessity of periodically lubrieating the joint with oil, is done away with.

The arrangement shown in Figs. 6 to '9 differs from that precedingly described merely by a modified configuration of the cover plate Ill. The latter is provided-on a portion of its circumference with a perpendicularly bent'off rim M which is directed towards the joint part 2 .and bears against the same. on the cover plate Ill extends approximately throughout the range beginning at one of the oblique faces 6 on the immovable stop plate I downwardly and around to the other oblique face 6 of the latter so that within this range the clearance gap between the stop plate land the cover The upper end of the cover plate I0 is semi-acircular.

The individual knee joints of the support are constructed similarly to the ankle joint described and they obviously have a corresponding angular range, approximating for example which extends between the shank rail and the thigh rail. In Fig. 1 the cover plate ID for the y th s means the setting up This projecting rim l4 knee joint is shown, which plate is fastened to the lower end of the thigh rail by two rivets (not shown) that are countersunk on both sides like the rivet 8.

The joint structure according to this invention makes possible th wearing of silk stockings on leg supports actually only from now on, whilst the supports are rendered so to speak invisible, which is highly important insofar as it is a fact that bodily disabled persons make an effort to disguise their abnormalities as much as possible. Further the joint structure according oting means extends, a lubricating bushing ex tending around said pivoting means within the opening of the said other joint portion, a spacer to the invention requires relatively little space in the direction of the pivot axis of the joint and the manufacture of the support is feasible by means of light metal material available on the home market. in conjunction with the fact that forging and chromium-plating can be dispensed with. At the same time the weight of the structure can b kept down, which is generally highly appreciated by the wearers, for example persons disabled in a leg. p

The joint structure according to the invention This facilitates the manufacture;

plate fixedly secured to the first joint portion adjacent the end of the other joint portion, said spacer plate and the connection portion of said other joint portion having abutment means facing in both directions of turning around said pivot for limiting the movement of the joint, and a cover plate secured on said spacing plate and extending over the intermovable portions of the spacing plate and adjacent connection portion of the other joint member .to prevent entanglement of garmentsor the like in the joint.

MAX MEIERHOFER.

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