SUMMARY OF THE INVENTION
This invention relates to crutches and more particularly, to a step and stair-adjustable crutch which is characterized by a crutch frame having a bisected crutch foot fitted with an adjusting cuff. The crutch frame and upper crutch foot segment are pivotally carried by the adjusting cuff for selective linear and angular adjustment of the frame and upper crutch foot segment with respect to the typically solid or plugged lower segment of the crutch foot, which is fixed to the adjusting cuff. The adjusting cuff is characterized by a generally cylindrical base fixed to the lower crutch foot and extended to define an upper elongated, flared or offset lip and lip receptacle cuff cone. Spaced-apart foot-alignment slots and foot angulation slots are provided in the cuff cone for selectively aligning with corresponding lock slots in the upper crutch foot segment and receiving a pair of rounded or tapered tabs or locks provided on oppositely-disposed, wishbone-shaped, resilient legs extending from the bottom end of an adjusting rod that is slidably disposed in or beside the upper crutch foot. The adjusting rod is typically terminated at the top end by a handle. Up and down manipulation of the adjusting rod facilitates engagement of the locks in the lock slots and selective engagement of the locks in the foot alignment slots and foot angulation slots for operation of the crutch in conventional fashion on flat surfaces with the crutch frame and the upper and lower crutch foot locked in substantially aligned orientation, and pivotal angulation of the crutch frame and upper crutch foot with respect to the lower crutch foot, for climbing and descending steps and stairs. Pivoting movement of the crutch frame is thusly facilitated at the cuff cone of the adjusting cuff, since the cylindrical cuff bottom is fixed to the lower segment of the crutch foot.
The first pair of oppositely-disposed foot alignment slots provided in one segment of the cuff cone are linearly aligned with the fixed lower crutch foot segment, while the second pair of oppositely-disposed foot angulation slots are angled with respect to the foot alignment slots and are located in the offset or flared lip receptacle portion of the cuff cone. The adjusting rod extends from the handle beneath the grip on the crutch frame downwardly, typically through a longitudinal bore or opening in the crutch foot, near or into the cuff cone. The top segment of the crutch foot typically pivotally mounts in the cuff cone of the adjusting cuff on a crutch pivot pin or bolt and may be bevelled to engage the fixed lower crutch foot segment and provide additional structural stability. The pair of resilient rod legs extends from the bottom end of the adjusting rod, typically in a wishbone configuration, into the irregularly-shaped cuff cone and each leg is provided with a tab or lock having at least a top curve or taper and preferably, also a bottom curve or taper. This design facilitates selective engagement of the tabs or locks with the respective companion lock slots in the top crutch foot segment and the corresponding spaced-apart aligned cone slots and angled cone slots, depending upon whether the crutch is to be used in the conventional mode on substantially flat or level ground with an aligned crutch foot and frame, or for climbing and descending steps or stairs with the crutch foot pivoted in angulated mode to facilitate adjustment of the user's weight into a safer step-traversal position. Accordingly, the crutch frame and pivotally bisected foot are designed to be oriented in a substantially vertical configuration while the crutch is used in conventional manner and the crutch frame pivoted into the angulated configuration with respect to the crutch foot for climbing and descending steps or stairs.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood by reference to the accompanying drawings, wherein:
FIG. 1 is a perspective view of a preferred embodiment of the stair-adjustable crutch of this invention, with the crutch frame angulated in position to ascend a set of steps or stairs;
FIG. 2 is a side view of the stair-adjustable crutch with the crutch foot configured in aligned configuration for conventional use of the crutch on a flat or level surface;
FIG. 3 is a side view, partially in section, of the hollow crutch foot and adjusting cuff elements of the stair-adjustable crutch illustrated in FIG. 1, more particularly illustrating the angulated configuration of the upper crutch foot in the adjusting cuff;
FIG. 4 is an exploded view of the stair-adjustable crutch illustrated in FIG. 2;
FIG. 5 is a longitudinal sectional view of the adjustable cuff and upper crutch foot elements of the stair-adjustable crutch, more particularly illustrating shaped locks provided on a pair of rod legs extending from an adjusting rod projecting through the upper crutch foot, for engaging a first set of spaced-apart slots to configure the stair-adjustable crutch as illustrated in FIG. 2;
FIG. 6 is a perspective view, partially in section, of the lower section of the stair-adjustable crutch, including the adjusting cuff, more particularly illustrating the locked configuration illustrated in FIG. 5;
FIG. 7 is a side view of the stair-adjustable crutch illustrated in FIG. 1, with the stair-adjustable crutch oriented in stair or step-descending configuration;
FIG. 8 is a longitudinal sectional view of the crutch foot and cuff cone, more particularly illustrating the stair-adjustable crutch adjusting cuff and foot configured as illustrated in FIGS. 1, 3 and 7;
FIG. 9 is a longitudinal sectional view of the crutch foot and cuff cone of the stair-adjustable crutch illustrated in FIG. 8, more particularly illustrating bending of the resilient rod legs inwardly inside the adjusting cuff by manipulation of the adjusting rod to facilitate insertion of the corresponding locks in the lock slots in the crutch foot and the angulated second set of slots in the adjusting cuff for selectively configuring the stair-adjustable crutch as illustrated in FIGS. 1 and 2 of the drawings;
FIG. 10 is a side sectional view of the cuff cone, more particularly illustrating an alternative bevelled embodiment of the upper foot end of the crutch foot in aligned configuration with respect to the lower foot end; and
FIG. 11 is a side sectional view of the cuff cone illustrated in FIG. 10, illustrating the alternative bevelled upper foot end embodiment wherein the upper foot end is angulated with respect to the lower foot end of the crutch foot.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring initially to FIGS. 1-4 of the drawings in a preferred embodiment, the stair-adjustable crutch of this invention is generally illustrated by reference numeral 1. The stair-adjustable crutch 1 includes a crutch frame 2, which may be conventional in configuration, with frame members 2a spaced apart intermediately by a grip 4 and at the top by an arm support 3. The frame members 2a are terminated at the bottom by a pair of parallel frame legs 6. A bisected crutch foot 8 defines an upper foot end 9 and a lower foot end 10 and the upper foot end 9 extends between the parallel frame legs 6 in selectively fixed or adjustable relationship. Frame leg bolts 7 typically extend through aligned openings (not illustrated) in the parallel frame legs 6 and through the corresponding foot openings 8a (FIG. 4) in the upper foot end 9 of the crutch foot 8, and are typically secured by nuts 5 (FIG. 2). An adjusting cuff 12 is fitted in the bisected crutch foot 8 and receives the upper foot end 9 and lower foot end 10 of the crutch foot 8, as hereinafter described. A rubber friction cup 25 is typically fitted to the lower end of the lower foot end 10 for friction-enhancing purposes during use of the stair-adjustable crutch 1.
Referring again to FIGS. 1-4, the adjusting cuff 12 is further characterized by a generally cylindrical cuff bottom 13 that is fixed to the lower foot end 10 of the crutch foot 8, typically by means of a transverse lower foot end pin or bolt 11, extending through a cuff opening 12a in the cuff bottom 13, and secured by a nut 5 (FIG. 4). An irregularly-shaped cuff cone 14 extends upwardly from the cuff bottom 13 and projects outwardly along one perimeter segment in offset, extended and flared fashion, to define an elongated lip 14a and a corresponding lip receptacle 14b (FIG. 4), for optionally accommodating the upper foot end 9 in a pivoted and angular orientation, as hereinafter further described. A pair of oppositely-disposed, aligned cone slots 15 is provided in the non-offset and elongated portion or segment of the cuff cone 14, while a pair of oppositely-disposed angled cone slots 16 is provided in the flared and offset portion of the cuff cone 14, below the elongated lip 14a and communicating with the elongated lip receptacle 14b, as illustrated in FIGS. 3 and 4. A crutch pivot pin or bolt 17 extends transversely through a second cuff opening 12a provided in the cuff cone 14 and the upper foot end 9 of the crutch foot 8 and is typically secured by a nut 5, to pivotally secure the upper foot end 9 and the crutch frame 2 on the cuff cone 14 above the lower foot end 10.
Referring now to FIGS. 2 and 4-6 of the drawings a stiff adjusting rod 18 extends from immediately beneath the grip 4 of the stair-adjustable crutch 1, longitudinally downwardly and typically slidably through a longitudinal bore or opening 24 (FIG. 4) in the crutch foot 8 and terminates above or in the cuff cone 14. A rod handle 19 is typically provided on the upper end of the adjusting rod 18, beneath and spaced from the grip 4 for manipulating the adjusting rod 18 up and down, as further illustrated in FIG. 2. A pair of resilient, typically wishbone-shaped rod legs 20 diverge from the downwardly-extending end of the adjusting rod 18 and terminate in corresponding oppositely-disposed, spaced-apart, fixed tabs or locks 21 (FIGS. 4 and 5). Each of the locks 21 is characterized by a top curve or taper 22 and may have a bottom curve or taper 23 (FIG. 5) for seating in a corresponding lock slot 9a (FIGS. 4, 8 and 9) in the upper foot end 9 and selectively engaging the oppositely-disposed, aligned cone slots 15 and the angled cone slots 16 provided in the cuff cone 14, for purposes which will be hereinafter further described. The rod legs 20 are typically constructed of a metal or plastic material having sufficient resilience and memory to exert an outward force on the inside surface of the cuff cone 14 and the lock slots 9a by each of the oppositely-disposed locks 21, responsive to linear manipulation of the adjusting rod 18 when gripping the rod handle 19, as illustrated in FIGS. 5, 6, 8 and 9 of the drawings and as further hereinafter described.
Referring now to FIGS. 10 and 11 of the drawings, in an alternative configuration of the stair-adjustable crutch 1, the bottom end of the upper foot end 9 of the crutch foot 8 is shaped to define a forward bevel 9c and a rear bevel 9d, that converge to a fulcrum 9b. Additional vertical support is thus provided in the crutch foot 8 as the fulcrum 9b contacts a plug 10a (illustrated in phantom) or the solid end of the lower foot end 10, as illustrated in FIG. 10. Support of the crutch foot 8 is also provided in the angulated configuration illustrated in FIG. 11, as the forward bevel 9c contacts the plug 10a or the solid end of the lower foot end 10, as illustrated. This embodiment serves to reduce the shear forces on the crutch pivot bolt 17.
In operation, referring to FIGS. 1, 2 and 5-9 of the drawings, under circumstances where it is desired to use the stair-adjustable crutch I in the conventional upright configuration illustrated in FIGS. 2, 5, 6 and 10, the adjusting rod 18 is initially forced upwardly by gripping the rod handle 19. This action bends and moves the spaced-apart rod legs 20 upwardly inside the cuff cone 14 and disengages the locks 21 from the oppositely-disposed lock slots 9a (FIG. 9) to facilitate positioning the crutch frame 2 and the upper foot end 9 into linear alignment with the lower foot end 10 (FIG. 2 ). The adjusting rod 18 is then forced downwardly by pressure applied to the rod handle 19 to facilitate re-engagement of the shaped locks 21 with the companion lock slots 9a and with the registering oppositely-disposed, aligned cone slots 15 at the curved or bevelled bottom taper 23 and locking of the lower foot end 10 of the crutch foot 8 to the upper foot end 9 (FIGS. 5 and 6). The stair-adjustable crutch 1 is then utilized to traverse a typically flat or level surface 27 in conventional, upright configuration, as illustrated in FIG. 2.
Alternatively, when it is desired to utilize the stair-adjustable crutch 1 to ascend a set of steps or stairs 28 as indicated in FIG. 1, the adjusting rod 18 is again manipulated upwardly by gripping the rod handle 19 to disengage the respective locks 21 from the opposed companion lock slots 9a and the corresponding spaced-apart, aligned cone slots 15, due to the top taper 22, as illustrated in FIG. 9. The crutch frame 2 and upper foot end 9 of the crutch foot 8, as well as the lock slots 9a, are then pivoted into the configuration illustrated in FIGS. 1, 3, 7, 8 and 11, with the upper foot end 9 disposed at an angle (alpha) (FIG. 3) with respect to the lower foot end 10 and resting in the elongated lip receptacle 14b of the angled, flared or offset cuff cone 14. The lock slots 9a and angled cone slots 16 are thusly aligned and downward motion or movement of the adjusting rod 18 pursuant to pressure applied to the rod handle 19 then engages the respective locks 21 with the lock slots 9a and the corresponding oppositely-disposed angled cone slots 16 (FIGS. 1 and 8), to lock the crutch frame 2 in angular relationship with respect to the lower foot end 10 of the crutch foot 8, as illustrated in FIG. 1. Using the stair-adjustable crutch 1 as so oriented, a user (not illustrated) can ascend the steps or stairs 28 (illustrated in phantom) with the body weight further forward than is possible under circumstances where the stair-adjustable crutch 1 is utilized in the conventional upright configuration illustrated in FIG. 2. This angulation increases the confidence level of the user regarding weight distribution and promotes efficiency, path-dependent stability and safety while ascending the steps or stairs 28.
Under circumstances where the steps or stairs 28 are to be descended as illustrated in FIG. 7, the position of the stair-adjustable crutch 1 is again oriented in the position illustrated in FIG. 1, such that the user's weight distribution is rearwardly of the angled lower foot end 10 of the crutch foot 8, thus again increasing confidence in the ability of the user to descend the steps or stairs 28 in a more efficient stable and safe manner.
It will be appreciated by those skilled in the art that the stair-adjustable crutch of this invention is characterized by convenience and flexibility, in that the respective stair and step ascending and descending modes, as well as use on level or substantially flat ground, can be effected quickly and may be easily implemented by application of upward and downward pressure to the rod handle of the adjusting rod, as heretofore described. Furthermore, the stair-adjustable crutch can be utilized in conventional fashion as further heretofore described, without the necessity of utilizing the foot angulation feature. Moreover, the stair-adjusting crutch is user-friendly, in that it can be utilized by large and small children as well as adults, by simply manipulating the adjusting rod by applying pressure to the rod handle, as heretofore described. Still further, the stair-adjustable crutch can be utilized singularly or in pairs, depending upon the needs of the user and either or both crutches can be adjusted in the appropriate fashion as described above, in order to walk on level ground or to ascend or descend set of steps or stairs, as heretofore described.
While the preferred embodiments of the invention have been described above, it will be recognized and understood that various modifications may be made in the invention and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the invention.
Having described my invention with the particularity set forth above,
Patent Grant
7357139
