US2208275A

US2208275A - Artificial knee

Info

Publication number: US2208275A
Application number: US150293A
Authority: US
Inventors: French J Conner; John A Mccann
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-06-25
Filing date: 1937-06-25
Publication date: 1940-07-16
Anticipated expiration: 1957-07-16

Description

July 16, 1940. J. J. McCANN ARTIFICIAL- KNEE- Filed June 25, 1937 2 Sheets-Sheet 1 INVENTOR.

July 16, 1940. J. J. MCCANN 2,208,275

ARTIFICIAL KNEE Filed June 25, 1937 2 Sheets-Sheet 2 I N VENT OR.

Patented July 16, 1940 UNITED STATES ARTIFICIAL KNEE John J. McCann, Burlin gton, N. J.; J. Conner French, Mercer County, and John A. McCann,

Burlington County, N. J., executors of John J.

McCann, deceased Application June 25, 1937, Serial No. 150,293

2 Claims.

This invention relates to artificial limbs and is concerned primarily with the knee joints of such artificial limbs.

At the present time there is available to the public an artificial limb including a knee joint, which is characterized as including a pair of links which are pivotally connected to the thigh piece and shin member of the leg respectively, and with which links are associated another pair of pivotally mounted links that are longer than the first mentioned links, and are also connected to the thigh and shin members respectively. In order that a knee joint of the type above identiiied be properly operable, it is necessary that the shorter of the pivotal links be movable between the longer pivotal'links. In the now known joints of this type this movement is accommodated by making the longer links of an arched or olfset formation whereby space through which the smaller pivotal links may move is provided. However, the use of the now known types of knee joints of the character above-noted is attended by certain disadvantages which are intended to be improved by the present invention.

With the foregoing in mind, this invention has in view as an important objective the provision of a knee joint for artificial limbs which comprises a pair of joint members, one for the thigh piece and one for the shin piece of the artificial limb. Each of these joint members is formed with a slot intermediate the faces thereof and which slotted portions are provided with pivotal pins whereby a'link is adapted to be mounted in the slotted portions of the joint members. The longer pivotal links are pivotally mounted on the outer faces of the joint members, and thus movement of the shorter pivotal link member be tween the longer outer pivotal members is provided. v

Important detailed features of the invention are associated with the provision of proper pivotal mountings for the above noted link members.

Another important phase of the present invention is the provision of a novel type of structure for positively and rigidly securing the joint members to the thigh and shin members respectively. In accordance with the present invention, the lower end of the thigh member and the upper end of the shin member are each provided with base plates, which are securely anchored to the respective members. The joint members of this invention are formed with flanges that are adapted to engage the base plates and be bolted thereto to securely affix the joint members to the respective base plates.

Other important details of the invention are associated in the particular manner in which the base plates are anchored to the thigh and shin pieces respectively.

Various other more detailed objects and ad- 5 vantages will in part become apparent and in part be hereinafter constituted as the description of the invention proceeds.

The invention, therefore, comprises an artificial limb including a thigh piece and a shin 1 piece each of which is provided with a base plate at the extremity adjacent the knee joint of the limb. Each of these base plates is anchored th the respective'thigh or shin piece by a rigid connection and securely affixed to each base plate is a joint member, the connection being established by a bolted flange arrangement. Each of the joint members is slotted intermediate its faces and a short link is pivotally mounted in said slotted portions. outer faces of said joint members are a pair of longer links and in such relationship to the shorter length as to have the latter pass therebetween under certain conditions of movement of the joint members. Each of the joint members is formed with a shoulder that extends substantially in the direction of the link members, and interposed between the shoulders of the two joint members is a resilient pad which is designed to be compressed incident to certain movement of the joint members. This same resilient pad also causes movement between the joint members in a manner that will be pointed out in detail hereinafter.

For a full and more complete understanding r of the invention references may be had to the following description and accompanying drawings wherein:

Figure 1 is a side view of that portion of an artificial limb which embodies a knee joint in accordance with the precepts of this invention,

Figure 2 is a transverse section of the knee joint, bringing out the arrangement of the joint members with respect to the thigh and shin pieces respectively,

Figure 3 is a side view, partly in section and partly in elevation, of the joint members per se,

Figure 4 is a view somewhat similar to Figure 3, showing the joint members in diiferent relative positions,

Figure 5 is a section through one of the joint members, bringing out the manner in which the outer links are pivotally carried thereby,

Figure 6 is an elevational showing of the parts constituting the pivotal mounting for the outer 5.5.

Pivotally mounted on the 20 receiving the base plate 25.

links. This view shows these parts in an exploded relationship,

Figure '1 is a sectional view similar to Figure 5, developing the pivotal mounting for the inner shorter link,

Figure 8 is an exploded elevational showing similar to Figure 9 of the parts constituting the mounting for the inner pivotal link,

Figure 9 is a viw of one of the joint members with parts broken away and shown in section to develop the slotted construction that accommodates the inner link, and

Figure 10 is a side view partly in section, and

partly in elevation of the inner link member;

per se.

Referring now to the drawings wherein like reference characters denote corresponding parts.

The thigh piece of an artificial limb is represented in Figures 1 and 2 by the reference character Ill. The thigh piece If] is of a hollow construction that is defined by a front wall ll, rear wall l2 and side walls 13, the walls II and i3 being connected by rounded corners to simulate the appearance of a natural thigh. The front 4 wall H is cut away as represented by the line at l4 and. the cut away portion is replaced by a removable piece [5 that may be taken out to obtain access to the joint mechanism that is obtained between continuations of the side walls i3 and the rear wall I2. A base plate identified at I5 is formed on each side edge with an ear I1, and each of the ears I1 is anchored to the walls ll, l2, and I3 respectively by a nut and bolt arrangement referred to generally at l8. Secured to the base plate [6 is one joint member which is referred to in its entirety by the reference character A, of which the detailed construction will be pointed out hereinafter.

The shin piece of an artificial leg is shown at I 9, and the upper portion of this shin piece is hollowed out to accommodate the base plate 20. The base plate 20 is formed with a plurality of ears 2] on its side edges which are bolted to the walls of the shin member l9 that define the recess Inasmuch as the wall surrounding this recess is thin, permanence and rigidity of the anchorage of the base plate is afforded by having the anchoring bolts shown at 22 pass through the outer metallic shield 23 that is also carried by the shin piece 19. The connecting member referred to in its entirety by the reference character B is carried by this base plate 20 and within the shield 23.

Referring now more particularly to Figure l, the connecting member A is shown as comprising a main body member 24 that is formed with a flange 25 that engages the base plate I6 of the thigh piece It and is securely anchored thereto by the nut and bolt arrangement identified at 26. Extending towards the rear wall l2 from the main body portion 24 of the joint member A is a nose portion 21 that is slotted as shown at 28 in Figure 3, and extending downward from the main body 24 is a shoulder 29 that is also clearly brought out in Figure 3.

The joint member B also comprises a main body portion 30 that'is formed with flanges 3| that engage the base plate 20 and are connected thereto by bolted nuts identified at 32. Extending rearwardly and upwardly from the main body 30 is a nose portion 33 that is also slotted as shown at 34. This nose portion 33 defines a shoulder 35.

At this point it is well to note that a pad of a resilient material such as sponge rubber is interposed between the shoulders 35 and 29 and is preferably secured to the shoulder 29 in any preferred manner as by an adhesive.

This resilient pad is identified at 36. A short link member 31 has one end pivotally mounted in the slotted portion of the nose 21 of the joint member A, the pivotal member being referred to generally by the reference character 38. The other end of the link 31 is pivotally mounted in the nose portion 33 of the joint member B, and the structure of the pivotal connection is identical with that at 38.

The detailed construction of the pivotal con-. nection at 3B is best described by referring to Figures '7, 8, 9, and 10. This connection is described in conjunction with the joint member A and it is to be understood. it is to be repeated in the joint member B.

The nose portion 21 of the jointmember A on each side of the slot 28 is formed with openings 33 that are enlarged as shown at 43. Each of the openings 39 is lined with a bushing 4| which is preferably of bronze to constitute a good bearing element. The end of the link 31 which is received in the slot 28 is formed with a circular opening 42 and extending through this opening 42 and the bushings 41 is a cylindrical sleeve shaped member 43, the inner surface of which is threaded as indicated at 44 in Figure '1. It is notable that the sleeve 43 is provided with a slight recess 45 and a set screw 46 has a pointed extremity which is adapted to be received in the recess 45. This set screw 43 is threaded in that portion of the link member 31 surrounding the opening 42 and serves to establish a non-rotating relationship between the link member 31 and the sleeve 43.

The screw 41 is threaded into one end of the sleeve 43 and has an enlarged fiat head 48 that is received in the enlargement 4!] of the opening 39 and this screw 41 is duplicated at the other end of the sleeve 43 as shown at 49. The heads 48' of the

screw members

41 and 49 may be provided with lubricating openings shown at 50.

A pair of link members 5! are disposed on each face of the joint members A and B and anchored thereto by pivotal connections referred to generally at 52 and 53. These

pivotal connections

52 and 53 are of identical construction and only one of them needs here be described for this specification.

Referring now more particularly to Figures 5 and 6, the main body portion 24 of the joint member A is shownas formed with an opening extending transversely there across and identified at 54'. This opening 54 is lined by a bearing member 55 which may be of bronze or other suitable material. The link 5| at the right hand side of 55 is formed with a threaded opening shown at 5B. A bearing pin of cylindrical formation is identified at 51 and is shown as having an enlarged shoulder which is provided with threads which are complemental to the threaded opening 56. This threaded shoulder is identified as 58.

The bearing pin 51 terminates in a slotted head 59 that engages against the link 5! on its outer face. The link 5i on the opposite face of the body portion 24 of the joint member A is provided with an opening 50, in which fits the free extremity of the bearing pin 51. 'The bearing pin 51 is of a hollow formation and the bore thereof is threaded and receives the headed screw member 6|, the head 62 of which overlaps the link 5| to retain the latter in position on the bearing pin 51. This bearing 51 is also threaded at the other end and receives a screw plug 63, the head of which is slotted as shown at 64 to provide for the engagement of a screw driver therewith. The cylindrical wall of the bearing pin 51 is provided with a lubricating opening 65 and a suitable lubricant such as grease is contained in the bore of the bearing pin between the members 6! and 63. It is evident that by screwing plug 63 inwardly, the lubricant'will be extruded through the sleeve 55 to thoroughly lubricate the outer surface of the bearing pin with respect to the sleeve 55.

With the thigh piece It) and the shin piece iii of the artificial limb in substantial alignment the pivotal links assume substantially the same :osition which is brought out in Figure 2. If the weight of the wearer is applied to the limb, the resilient pad 36 will be compressed in the manner brought out in Figure 3. When the weight of the wearer is removed from the thigh piece it the resilient pad 36 will cause a flexing on the shin piece it with respect to the thigh piece it which action is comparable to natural walking movement. If the shin piece !9 is further moved to reduce the angle between this piece and the thigh piece iii, the pivotal mounting of the link 31 will be moved between the links 5i in the manner clearly brought out in Figure 4. It is evident with the arrangement illustrated in the drawings and described in the foregoing specification it is not necessary to provide any offset or bowed construction in the links 5| as the link 37 and pivotal mounting thereof is readily movable therebetween.

While a preferred specific embodiment of the invention is hereinbefore set forth, it is to be clearly understood that I am not to be limited to be connected to the shin piece of an artificial limb, said second joint member having an upwardly extending nose portion defining a shoulder spaced from the shoulder on the first mentioned joint member, said last mentioned nose being slotted, a link having each extremity disposed in the slots in the said joint members and pivotally mounted therein, a pair of links longer than the first mentioned link disposed on opposite faces of the joint members and pivotally connected there to their extremities, and a resilient pad of appreciable thickness which is carried by one of theshoulders, said pad being movable with the shoulder relative to the other shoulder and subject to compression by and between the shoulders as said shoulders approach a limit of movement toward one another, said compressed pad having a shape of materially reduced thickness whereby energy is stored in said pad, to separate said shoulders when pressure on the joint is released.

2. A knee joint for artificial limbs comprising a joint member adapted to be connected to the thigh piece of an artificial limb and being formed with a nose portion at one side thereof, said joint member also being formed with a shoulder, a second joint member adapted to be connected to the shin piece of an artificial limb, said second joint member having an upwardly extending nose portion defining a shoulder spaced from the shoulder on the first mentioned joint member, linkage pivotally connected to each of said nose portions, a pair of links longer than the first mentioned linkage and disposed on opposite faces of the joint members and pivotally connected thereto at their extremities, and a resilient pad of appreciable thickness which is carried by one of the shoulders, said pad being movable with the shoulder relative to the other shoulder and subject to compression by and between the shoulders as said shoulders approach a limit of movement toward one another, said compressed pad having a shape of materially reduced thickness whereby energy is stored in said pad to separate said shoulders when pressure on said joint is released.

JOHN J. McCANN.