US3710807A

US3710807A - Crutches

Info

Publication number: US3710807A
Application number: US00200031A
Authority: US
Inventors: C Ferry
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-11-18
Filing date: 1971-11-18
Publication date: 1973-01-16
Anticipated expiration: 1990-01-16

Abstract

There is disclosed herein a sectional, metallic crutch of telescoping tubular construction having continuous, end-to-end columnar support between the handle of the crutch and the lower tip thereof whereby no substantial strain is placed upon fastening means for connecting the detachable sections.

Description

United States Patent 1191 Ferry [54] CRUTCHES [76] Inventor: Carolyn Patricia Ferry, 2580 North Moreland Blvd., Shaker Heights, Ohio 44120 [22] Filed: Nov. 18, 1971 [2]] Appl. No.: 200,031

[52] US. Cl ..135/49, 135/475 [51] Int. Cl.., ..A45b 1/00 [58] Field of Search.l35/47.5, 49, 50, 51, 52,15 PO,

[56] References Cited UNITED STATES PATENTS 2,711,183 6/1955 Lofstrand ..l35/50 1 Jan. 16,1973

2,788,793 4/1957 Abbott ..l35/49 2,811,978 11/1957 Russell ..l35/50 X 3,157,187 11/1964 Murcott 1 35/49 Primary Examiner-.l. Karl Bell Attorney-J. H. Slough [57] ABSTRACT There is disclosed herein a sectional, metallic crutch of telescoping tubular construction having continuous, end-to-end columnar support between the handle of the crutch and the lower tip thereof whereby no substantial strain is placed upon fastening means for connecting the detachable sections.

8 Claims, 12 Drawing Figures CRUTCIIES This invention relates to crutches and particularly to sectional, demountable crutches such as the type disclosed in applicant's prior US. Pat. No. 3,338,387 issued Aug. 29, 1967, and US. Pat. No. 2,711,183 issued June 21, 1955, to A. R. Lofstrand, Jr., such crutches commonly being made from lightweight tubular material such as aluminum tubing. However, the invention may be applied to other types of crutches of other materials.

It is well known in the art that a walking crutch comprises a main weight-receiving member connected to a vertical supporting shaft portion. In this type of construction, the entire vertical stress is transferred through the weight-receiving member to the supporting shaft therebelow.

To make a given crutch adaptable for users of different heights, the vertical shaft portion is preferably longitudinally adjustable. The shaft is commonly made up of a plurality of separable, telescoping tubular sections adjustable as to length by simple pin means disposed through selected aligned apertures in the tubing walls of the interfitting sections. Thus, when the crutch is in use, the stress is transferred from one section to another through the pins to the relatively small areas defining the apertures. The pins are necessarily made of a material having great shear strength such as strong steel, but in lightweight tubing, such as aluminum, the apertures soon tend to enlarge and become misshapen.

The present invention provides a sectional,

demountable crutch of the type set forth above wherein there is continuous end-to-end abutment of portions of the crutch sections whereby stress is transferred from one section to another coaxially with and directly against an end of another portion, and no substantial amount of stress is ever placed upon the adjustment pins. Thus substantially all wear at the pin apertures is eliminated and a continuous columnar support is provided from the weight-receiving member to the floor or ground.

The general object of this invention is to provide an improved sectional type crutch.

Another object of the invention is to provide a crutch of the above type which provides a substantially stronger support shaft from the weight-receiving member downwardly than is found in known crutches.

Still another object of the invention is to provide a sectional crutch as set forth above of telescoping construction wherein there is continuous columnar support throughout the support shaft.

, Yet another object of the invention is to provide a crutch as set forth above which is longitudinally adjustable and includes means maintaining said continuous columnar support even when the crutch is lengthened.

A still further object of this invention is to provide a sectional, longitudinally adjustable crutch of telescoping construction, adjustable by projecting pin means through aligned apertures in telescoped portions of tubing, wherein no substantial stress is applied to the pin means or apertures in any adjusted position.

Other objects of the invention and the invention itself will be readily apparent from the following description thereof and the accompanying drawings, in which said drawings:

FIG. 1 is a side elevation of an embodiment of the crutch of this invention;

FIG. 2 is an enlarged section taken substantially along the line 2-2 of FIG. 1;

FIG. 3 is a still further enlarged cross section taken along the line 3--3 of FIG. 2;

FIG. 4 is a cross section taken along the line 44 of FIG. 2 also drawn to the scale of FIG. 3;

FIG. 5 is a cross section taken along the line 5-5 of FIG. 2 also drawn to the scale of FIG. 3;

FIG. 6 is a longitudinal section showing an enlarged detail of a spring loaded pin fastener also drawn to the scale of FIG. 3;

FIG. 7 is a side elevation of an upper section of the crutch drawn to the scale of FIG. 2;

FIG. 8 is a side elevation of the medial section of the crutch drawn to the scale of FIG. 2;

FIG. 9 is a side elevation of the lower section of the crutch drawn to the scale of FIG. 2;

FIG. 10 is a partial sectional view of the lower section and part of the medial section in an extended adjusted position with a spacer disposed above the lower section;

FIG. 11 is a fragmentary, exploded view of the part shown in FIG. 10; and

FIG. 12 is a fragmentary, exploded view similar to FIG. 11 showing different size spacers.

Referring now to the drawings in all of which like parts are designated by like reference numerals, FIG. I shows a sectional crutch generally indicated at 1 comprising three separable sections: an upper section 2, a medial section 3, and a lower section 4. The crutch is preferably made of lightweight metallic tubing of such material as aluminum. As herein illustrated, the tubing is circular in cross section but the invention is not limited to this shape or material.

Referring now particularly to FIGS. 2-4, 6 and 7, the upper section 2 comprises a length of tubing obtusely bent in the middle to provide a normally vertical lower portion 10 and a slightly outwardly angled upper portion 11. Said upper portion is surmounted by a metallic clevis 12 having upwardly projecting parallel arms 13 and a reduced, downwardly directed, integral plug 14 which interfits the upper end of a short, tubular stem 15 and is secured therein in any preferred manner. As shown a transverse rivet 16 is used for this purpose. The stem 15 is adapted to slidably telescope into the upper portion 1 l of the upper section 2 and is provided internally with a spring loaded pin fastener 17 of the type detailed in FIG. 6. Said fastener comprises a hairpin spring 18 the arms 18a of which are provided at their distal end portions with laterally outwardly projecting pins 19 adapted to project outwardly through diametrically opposed apertures 20 in the walls of the stem- 15. The pins 19 are of sufficient length to selectively engage longitudinally spaced, diametric pairs of apertures 21 in the upper portion 11 and project radially outwardly a slight distance beyond said upper portion.

The clevis 12 is adapted for mounting an arm gripping member 22 in the form of a C-shaped spring clip having a pivot block 23 mounted to the outer surface thereof in any suitable manner opposite to the opening in said arm grip. A pin 24 projects through suitably aligned openings in the arms 13 of the clevis l2 and the pivot block 23 whereby the arm grip 22 can readily tilt to the optimum angle when gripping the arm of the user.

From the foregoing, it will be readily understood that the crutch is vertically adjustable by placing the pins 19 in different pairs of diametrically opposite apertures 21 in the upper portion 11 and that the said pins can be moved from one set of apertures to another simply by pressing firmly inwardly on the ends of the pins and pulling or pushing in the axial direction on the clevis 12 or arm grip 22.

Adjacent to the upper end of the lower portion there is provided a closely fitting sleeve joint 26 telescoped over and secured to said lower portion by a transverse rivet 27. A horizontally outwardly projecting, integral handle 28 extends outwardly from the sleeve joint 26 and is covered with a suitable resilient handgrip 29 in a well-known manner whereby the crutch may be grasped by the hand at said handgrip with an upper portion of the arm engaged by the C- shaped arm grip 22.

The medial section 3 is best understood by reference to FIGS. 2, 5, and 8 and comprises a lower tube 30 of the same diameter as the lower portion 10 of the upper section 2, said lower tube engaging a smaller, upper rod tube 31 of such diameter as to slidably telescope into said lower portion 10. Substantial portions of the

tubes

30 and 31 overlap, and said tubes are detachably fastened together by a spring loaded pin fastener 17, the pins 19 of which project through diametrically opposed pairs of

apertures

32 and 33 in the lower and

upper tubes

30 and 31, respectively. The upwardly projecting portion of the upper tube 31 is adapted to project entirely into the lower portion 10 which affords a socket therefor whereby the axially directed lower edge of said portion 10 abuts the axially directed upward edge of the lower tube 30. The upper portion of the upper tube 31 is provided with another spring loaded pin fastener 17, pins 19 thereof being adapted to project outwardly through a second pair of diametrically aligned apertures 33 in said upper tube and similar diametrically oppositely positioned apertures 34 in the lower portion 10 of the upper section 2. As shown in FIG. 2, the upper, axially directed edge of the upper tube 31 of the medial section 3 engages the lower end of a tubular spacer or abutment means 35 the upper end of which abuts the transverse rivet 27 of the sleeve joint 26. The transverse rivets such as 27 are preferably made from steel having substantial shear strength whereby the spacer 35 and the underlying upper tube 31 are rigidly backed up at this point.

The lower section 4 is best understood by reference to FIGS. 2 and 9. Said section 4 comprises a single rod or tube member 49 of such diameter as to slidably interfit the lower end portion of the lower tube 30 of the medial section 3 which affords a socket for said member. The lower end of the tube member is provided with a resilient tip 41 for contacting the floor, ground, or other supporting surface. The upper portion of said tube member 40 is provided internally with a spring loaded pin fastener 17 of the type detailed in FIGS. 3 and 6 and hereinbefore described, the pins 19 of said fastener projecting through suitable apertures 42 in said tube member and the uppermost of longitudinally spaced pairs of diametrically opposed apertures 43 in the lower end portion of the lower tube 30 of the medial section 3. It will be noted that in this location the upper axially directed edge of the tube member 40 abuts the lower axially directed edge of the upper tube 31 whereby there is a solid, end-to-end abutment of tube sections extending downwardly from he transverse rivet 27 at the sleeve joint 26 and comprising the c'ylindrical spacer or abutment means 35, the upper tube 31, and the tube member 40. It will further be noted that throughout substantially the greater portion of this length, double tubular walls are provided comprising the lower portion 10 of the upper section 2 and the lower tube 30 of the medial section 3. Thus, with all of the downward pressure being exerted from the level of the sleeve joint 26 at the handle 28, an effectively solid column of metal is provided to the ground or floor and no shear force is applied at the pins 19 of the three lower spring loaded pin fasteners 17 of the intermediate and lower sections. It follows that metal surrounding the apertures in the tubular walls receives very little wear.

When it is desired to lengthen the crutch 1 from the handle 28 to the tip 41, the tube member 40 is adjusted downwardly by moving the pins 19 of the lowermost spring loaded pin fastener 17 to a lower pair of apertures 43. For example, FIG. 10 shows these pins in the lowermost pair of said apertures whereby the upper end of the tube member 40 is now spaced from the lower end of the upper tube 31. To maintain solid columnar support at this point, there is provided a short tubular spacer 45 of the exact axial length to bridge this gap. FIG. 11 shows, in exploded view, the relationship between the lower end portion of the lower tube 30, the spacer 45 and the tube member 40. FIG. 12 is a similar, fragmentary exploded view showing the manner in which spacers of different sizes and/or length may be used depending upon what downward adjustment is called for. An axially shorter spacer 46 is of such length that the pins 19 of the lowermost fastener 17 could be seated in the second pair of holes or apertures 43 counting upwardly from the bottom. A still smaller spacer 47 would allow use of the third set of apertures 43 counting upwardly. Where it is necessary to frequently disassemble the crutch, such as for packing in the carrying case disclosed in applicants aforementioned patent, the spacers may be secured in place by any suitable means such as a rivet 48 shown in broken line in FIG. 10.

It will be readily understood from the foregoing that any combination of spaced apertures and spacers may be used in carrying out the basic principal of maintaining solid columnar support from the handle 20 to the tip 41 with the majority of such distance having double walled tubular support. It will also be understood that the inner members such as the stem 15, tube 31,

spacers

35, 45, 46, and 47, and tube member 40 do not have to be tubular or hollow as long as means are provided for mounting fastener means suchas the pins 19 in the

members

15, 31, and 40. As used in the claims, the term rod is intended to include both tubular and solid elongated shaft portions.

It will be understood that many changes in the details of the invention as herein described and illustrated may be made without, however, departing from the spirit thereof or the scope of the appended claims.

Iclaim:

1. A sectional, demountable crutch having a supporting shaft; said shaft comprising a plurality of separable sections; a weight-receiving member secured to an uppermost of said sections; said uppermost section comprising a tubular, downwardly open socket portion; abutment means disposed inside of said upper section substantially at the level of said weight-receiving member and defining the inner end of said socket portion; a section disposed below said upper section having a portion thereof telescoped into said socket portion; detachable fastening means carried by one of said sections, said fastening means including means projecting through aligned openings in said telescoped portion and socket portion for connecting said sections together; said shaft sections comprising shaft members, including said portion telescoped into said socket portion, in continuous end-to-end abutting relationship extending from said abutment means to the lowermost tip of said crutch and sustaining all of the stress of weight placed on said weight-receiving member whereby none of said stress is placed upon said fastening means.

2. A crutch as set forth in claim 1: said shaft comprising three of said separable sections; said second mentioned section comprising an inner rod disposed within an outer tube, said inner rod projecting upwardly above the upper end of said outer tube and providing said portion telescoped into said socket of said upper section, the lower end of said inner rod being disposed inwardly of the lower end of said outer tube whereby to provide a second downwardly open socket; means attaching said inner rod within said outer tube; a third section comprising an elongated rod, an upper end portion of said elongated rod being telescoped into said second socket; second fastening means detachably connecting said second mentioned and third sections together in the manner of the said first mentioned fastening means; the upper and lower ends of said inner rod abutting said abutment means and the upper end of said elongated rod, respectively, and providing continuous columnar support between said weight-receiving member and said tip.

3. A crutch as set forth in claim 1: one of said portions having a plurality of longitudinally spaced apertures for receiving said fastening means whereby said supporting shaft is lengthened; and spacer means adapted to be disposed within said socket portion in abutting relationship with both said abutment means and the upper end of said telescoped portion at a selected longitudinal adjustment of said support shaft whereby to maintain the continuous end-to-end abutting relationship of said shaft members.

4. A sectional demountable crutch comprising separable upper, middle, and lower crutch sections; said upper section comprising a tubular member; a substantially horizontal weight-receiving member secured to said upper section; an abutment member secured within said upper section adjacent to the level of said weight-receiving member and defining the inner end of a first downwardly open socket formed by the lower end portion of said upper section; said middle section comprising inner and outer, telescoped tubes attached to each other, said inner tube projecting upwardly above said outer tube and adapted to project into said first socket, the lower end of said inner tube being recessed within said outer tube and defining the inner end of a second downwardly open socket formed by the lower end portion of said outer tube; said lower section comprising a tube adapted to telescope within said second socket; said inner tube and said lower section having fastener means mounted therein comprising outwardly spring biased pins projecting through aligned apertures in said inner tube and lower end portion of said upper section, and said lower section and said lower end portion of said outer tube, respectively, whereby said sections are detachably connected together; the upper end of said inner tube of said middle section abutting said abutment member and the lower end of said inner tube abutting the upper end of said lower section and providing continuous columnar support from said weight-receiving member to ground level for sustaining stress placed on said handle whereby none of said stress is placed upon said fastening means.

5. A crutch as set forth in claim 4: said lower end portion of said outer tube having a plurality of longitudinally spaced apertures for receiving said spring biased pins whereby said lower section can be longitudinally adjusted relative to said second socket to lengthen said crutch; and spacer means adapted to telescope into said second socket, said spacer means being of such length as to provide abutting relationship with both the lower end of said inner tube and the upper end of said lower section at a selected longitudinal adjustment of said crutch to maintain said continuous columnar support.

6. A crutch as set forth in claim 5: means securing said spacer means within said second socket whereby to permanently adapt said crutch for a taller user.

7. A crutch as set forth in claim 5: said spacer means comprising a plurality of spacers of varying lengths corresponding to the spacing between said spaced apertures, said spacers adapted to be inserted in said second socket singly or in combination to maintain said continuous columnar support at each longitudinal adjustment of the crutch.

8. A crutch as set forth in claim 4: said inner tube of said middle section having a second fastener means mounted therein comprising outwardly spring biased pins projecting through other aligned apertures in said inner and outer tubes.