WO2001037696A1

WO2001037696A1 - Swivel suspension for medical support equipment

Info

Publication number: WO2001037696A1
Application number: PCT/US2000/031704
Authority: WO
Inventors: Joseph R. Curiale
Original assignee: Hessa Medical, Incorporated
Priority date: 1999-11-23
Filing date: 2000-11-17
Publication date: 2001-05-31
Also published as: WO2001037696A8; AU1620901A

Abstract

A shock absorbing and swivel cylinder apparatus (16) for a support device is provided, having a socket bushing (60) and compression spring (64) therein supported by a thrust bearing (66) that provides for low-friction rotational movement of the upper part of the support relative to the lower part of the support.

Description

Swivel Suspension for Medical Support Equipment

Technical Field

The present invention relates to medical support equipment and, more particularly, to a rotation and suspension mechanism that allows crutches, wheelchairs, prosthetics and similar support equipment to compress and swivel as needed.

Background Art

Many medical support devices have been developed to assist in user comfort and safety and, in particular, a variety of crutch suspensions and swivel designs have been developed for these purposes. U.S. Patent Nos. 2,397,499 of McGowan, 2,398,534 ofKlausnitzer et al, 2,856,943 of Sparlin, and 2,888,022 of Fanning disclose various suspension and/or swivel designs that improve the performance of a crutch. To reduce friction within their suspension mechanisms, some of these patents disclose designs that provide bearings and/or bushings to reduce friction in the linear, telescoping movement of the upper crutch component on the lower crutch component.

The present invention improves upon the designs shown in these patents and provides a superior shock absorption and swivel mechanism for incorporation into crutches, wheelchairs, prosthetics and the like, resulting in improved performance and enhanced user convenience. Summary of the Invention

In a preferred embodiment, the medical device of the present invention assists in the mobility of an injured person and includes first and second tubular members linearly movable relative to each other in a telescoping manner, with the first member having a lower end and the second member having an upper end adapted to fit into the lower end of the first member in a sliding manner to permit linear relative movement between the first and second members. The second member is adapted to engage the floor as the injured person moves around and the first member is adapted to support a part of the injured person's body for assisted movement. In alternative embodiments, the first and second members may form part of the support structure for sporting equipment, toys and the like.

The present invention improves upon the prior art through the provision of a novel swivel and compression mechanism comprising a first bushing adjacent the lower end of the first member for providing low friction linear and rotational movement between the first and second members, and an abutment within the first member spaced from the upper end of the second member. A second socketed bushing having a socket therein is mounted to the upper end of the second member, and a compression spring is carried within the socket of the second bushing. The compression spring has an upper end biased against the abutment in a manner providing shock absorption to the first member relative to the second member. Finally, a bearing is provided between the lower end of the compression spring and the socket of the second bushing for providing low-friction rotational movement of the compression spring within the socket. In use, low friction movement between the first and second members is achieved as the first and second members move both linearly with respect to each other and rotationally with respect to each other.

Thus, the present invention provides a compression and rotation apparatus that can be universally configured and utilized as needed for a given support device. In a preferred embodiment, the shock absorption/swivel apparatus is incorporated into medical support devices, such as a crutches, walkers, canes, wheelchairs, gurneys, prosthetics and the like. In a particularly preferred embodiment, the present invention provides an improved crutch with superior shock absorption and rotation capabilities.

These and other features, objects, and advantages of the present invention will become apparent from the following detailed description of the invention, when read in conjunction with the accompanying drawings, and the claims, which are all incorporated herein as part of the disclosure of the invention.

Brief Description of the Drawings Throughout the several views, like reference numerals refer to like parts, wherein:

Fig. 1 is a front elevation view of the dynamic response crutch of the present invention;

Fig. 2 is a sectional view of the shock absorbing and swivel cylinder apparatus of the crutch of Fig. 1;

Fig. 3 is a cross-sectional view of the shock absorbing and swivel cylinder apparatus of Fig. 2, shown with the crutch in two phantom rotational positions

Detailed Description of the Invention Reference will now be made in detail to the following preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that the described embodiments are not intended to limit the invention specifically to those embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims.

Referring to Fig. 1, a particularly preferred embodiment of the present invention provides an improved crutch designated by reference numeral 10, which includes an upper crutch arm and shoulder support 12 and a lower crutch component 14, with a shock absorbing and swivel cylinder apparatus 16 joining the upper and lower crutch components. Lower crutch component 14 includes a foot pad 18 mounted at the lower end of an elongated upright tubular leg 20 that is joined to cylinder apparatus 16. Upper crutch support 12 includes a pair of elongated spaced tubular side bars 22, 24 joined near their midpoint by a handle 26 that can be adjustably mounted between side bars 22, 24 at a variety of vertical positions by means of vertically spaced and aligned holes (not shown) in the side bars. Upper crutch support 12 further includes a saddle assembly 28 that comprises a pair of adjustable, downwardly extending telescoping sleeves 30, 32 joined by a padded under arm saddle 34. In order to adjust the vertical height of the crutch, spring pins 36 are provided in each side bar 22, 24 and sleeves 30, 32 include vertically spaced holes (not shown) for receiving spring pins 36. Depression of spring pins 36 inwardly out of a hole in a side bar permits longitudinal vertical movement of saddle assembly 28 about side bars 22, 24.

An optional lock spring hinge mechanism 40 is provided in each side bar 22, 24 between handle 26 and cylinder apparatus 16, to permit folding of the upper crutch against the lower crutch for compact transport or storage.

Referring to Fig. 2, cylinder assembly 16 includes a tubular side wall 44 secured between the lower ends of side bars 22, 24. Approximate its midpoint, side wall 44 includes a shoulder 50 that defines a narrow-wall upper side wall 46 and a thicker- wall lower side wall 48. A bushing ring 54 is press-fit into the bottom edge of lower side wall 48 and slidably engages leg 20 for low-friction linear and rotational movement between the upper and lower crutch components. An end cap abutment 51 is slip fit into the top end of upper side wall 46 and secured to upper side wall 44 by means of a solid rivet 52 to side bars 22, 24. At the top end of lower leg 20, a socket-like bushing 60 is press fit into leg 20 and forms an upwardly facing socket 62. Socket bushing 60 is dimensioned to closely fit within upper side wall 46 in order to provide a tight, yet slidable and rotatable engagement between leg 20 and cylinder 44. The underside of end cap 51 includes a circular recess 68 for receipt of the upper coil of a compression spring 64. The lower coil of compression spring 64 rests on a thrust bearing 66, which allows for rotation of compression spring 64 with side bars 22, 24 and the upper half of the crutch. Socket bushing 60 also functions to contain thrust bearing 66 therein and in contact with compression spring 64 during linear and rotational movement of the upper crutch.

In an alternative embodiment, a cylindrical tubing (not shown) made of silicone rubber or like material may be positioned inside of compression spring 64, with the advantage of providing a buffer and relieving pressure on the compression spring. Appropriate cylindrical tubing materials may be obtained from, e.g., Cal-Neva Supply, Inc. of San Leandro, CA and Pacific Die-Cut Industries of Hayward, CA. The materials for the other components discussed herein can be made from a variety of commonly available materials, such as aluminum and steel, as well as nylon and other structural plastics for lower stress components. Tubular first and second members are preferred but not necessarily required. Preferably, bushings 54, 60 are made of a low-friction, self-lubricating material such as nylon MDS, and abutment 51 is made of aluminum or other suitable metal or structural plastic.

Referring to Fig. 3, when a person using crutch 10 walks around a corner, it is desirable for the upper part of the crutch to pivot about the lower part of the crutch that is in contact with the ground. Pivoting of the upper crutch allows the saddle assembly and handle to remain in alignment with the user's body and thereby avoids pivoting of the lower crutch, which needs to maintain firm engagement with the ground. Fig. 3 shows saddle assembly 28 in phantom in a first position A and a rotated, second position B, with the angle of rotation being designated by reference character θ. When saddle assembly 28 rotates, cylinder apparatus side wall 46 rotates about socket bushing 60 and, depending on the friction that develops at the bushings, the compression spring 64 may or may not rotate to some degree.

When rotating, the upper crutch components are carried on thrust bearings 66, which facilitate low friction rotation of the upper crutch, providing enhanced user comfort and safety during usage where turning movements are required. In addition, low friction movement between the first and second members is achieved as the first and second members move both linearly and rotationally with respect to each other. It is contemplated that the bushings, side wall and bearings may be easily modified to achieve a desired level of friction, depending on the needs of the particular support device. Similarly, the compression spring 64 may be modified as necessary to adjust the tension to a provide a level of shock absorption appropriate for the particular device.

While the preferred embodiment has been disclosed in the form of a crutch, it is apparent that the present invention could be easily incorporated into any number of medical support devices for assisting in mobility of an injured or handicapped person. For example, given the teachings in this specification, one of skill in the art could readily adapt devices such as walkers, canes, wheelchairs, gurneys, carts and prosthetics to incorporate the swivel and compression mechanism described herein. A modification of existing prosthetic designs to incorporate the improved shock absorption and rotation features provided by the present invention would be particularly useful for physically-active handicapped individuals who participate in sports requiring significant twisting and/or lateral mobility, such as basketball and tennis. Alternatively, the swivel suspension may also find significant non-medical uses in sporting equipment (e.g., skis, skateboards, skates, and bicycles), toys (e.g., tricycles, wagons, bigwheels and the like), strollers, carts (e.g., shopping, gardening, general purpose), handcarts, dollies, trailers and the like. The present invention has utility any where there are first and second members linearly movable relative to each other in a telescoping manner. The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto when read and interpreted according to accepted legal principles such as the doctrine of equivalents and reversal of parts.

Claims

The invention claimed is:

1. A medical device for assisting in mobility of an injured person, comprising, first and second members linearly movable relative to each other in a telescoping manner, said first member having a lower end and said second member having an upper end adapted to fit into the lower end of said first member in a sliding manner to permit linear relative movement between said first and second members, said second member adapted to engage the floor as the injured person moves around and said first member adapted to support a part of the injured person's body for assisted movement, a first bushing adjacent said lower end of said first member for providing low friction linear and rotational movement between said first and second members, an abutment secured to said first member and spaced from said upper end of said second member, a second socketed bushing having a socket therein and mounted to said upper end of said second member, a compression spring carried within said socket of said second bushing and having an upper end biased against said abutment, for providing shock absorption to said first member, and a bearing between a lower end of said compression spring and said socket of said second bushing for providing low-friction rotational movement of said compression spring within said socket, whereby low friction movement between said first and second members is achieved as said first and second members move both linearly with respect to each other and rotationally with respect to each other.

2. The medical device of Claim 1, wherein said bearing provides for rotational movement of said compression spring relative to said second member.

3. The medical device of Claim 2 wherein said bearing comprises a roller bearing.

4. The medical device of Claim 2 wherein said second socket bushing is adapted to contain said bearing therein and in contact with said compression spring during linear and rotational movement of said first member.

5. The medical device of Claim 1, wherein said first and second members are tubular.

6. A rotation and compression apparatus for a support having first and second members which move linearly and rotationally with respect to each other, said apparatus comprising: a first bushing adjacent a lower end of the first member for providing low friction linear and rotational movement between the first and second members, an abutment secured to the first member spaced from the upper end of the second member, a second socketed bushing having a socket therein and mounted to the upper end of the second member, a compression spring carried within the socket of said second bushing and having an upper end biased against said abutment, for providing shock absorption to the first member, and a bearing between said lower end of said compression spring and said socket of said second bushing for providing low-friction rotational movement of said compression spring within said socket, whereby low friction movement between the first and second members is achieved as the first and second members move both linearly with respect to each other and rotationally with respect to each other.

7. The apparatus of Claim 6, wherein said bearing provides for rotation movement of said compression spring relative to the second member.

8. The apparatus of Claim 7, wherein said bearing comprises a roller bearing.

9. The apparatus of Claim 7, wherein said second socket bushing is adapted to contain said bearing therein and in contact with said compression spring during linear and rotational movement of the first member.

10. An improved crutch comprising an upper and a lower crutch support and a shock absorbing and compression cylinder apparatus, said cylinder apparatus further comprising: a tubular side wall secured to lower end of said upper crutch support, said side wall having a narrower upper side wall and a thicker lower side wall; a first bushing positioned at the bottom of said lower side wall which slidably engages said lower crutch support; a second bushing comprising a socket containing a bearing, said socket positioned at the top end of said lower crutch support and dimensioned to closely fit within said upper side wall; an end cap having a circular recess secured to said upper side wall and spaced from said second bushing; and a compression spring positioned between said bearing and said circular recess in said end cap; wherein said cylinder apparatus allows for rotation and compression of said upper crutch support with said lower crutch support.

11. An improved crutch according to Claim 10, further comprising a lock spring hinge to permit folding of the upper crutch support against the lower crutch support for compact transport or storage.