GB2494906A - A support foot having a resiliently biased pivot - Google Patents

Abstract

A foot 100 for use at the end of a support tube 200 comprises a retaining member suitable 110, that may be for insertion into the end of the support tube 200, the retaining member may comprising a socket; an attachment member 120 that may be a ball that is retained within the socket such that the ball is free to rotate with respect to the retaining member 110; and a base 130 attached to the attachment member such that the base 130 extends beyond the support tube 200, in use. The device further comprises an elastic member 140 attached to the foot 100 such that the elastic member 140 tends to bias the attachment member 120 and base 130 assembly into a chosen orientation with respect to the retaining member 110. The retaining member may be formed in two halves that are held together when the retaining member is located inside the support member. The foot may be for use on crutches, a walking stick, furniture or scaffolding.

Description

SUPPORTING FOOT

Field of the Invention

This invention relates to a foot for use at the end of an elongate support, such as a walking stick.

Background to the Invention

Walking sticks, and other walking aids such as frames, frequently comprise a tip with is composed of a high friction material, such as rubber, in order to provide greater friction between the stick and the ground in use. Often the tip comprises a rubber ferrule which is fitted to the stick. This is beneficial because in use, a user will typically place the stick to the side of their body and lean against it; placing their weight in such a way that the tip of the stick will experience a force parallel to the surface on which it rests. The use of a rubber ferrule helps to prevent the tip slipping out of position.

However! ferrules do have a number of flaws. For example, in use, walking sticks are typically placed such that the stick is at an angle compared to the body of the user, and so typically at an angle compared to the vertical. This means that the ferrule does not rest flat upon the ground. Similarly, uneven walking surfaces can prevent the ferrule from making a flat contact with the ground. This reduces the surface area of the ferrule which is in contact with the ground, and consequently reduces the friction which would otherwise prevent slipping. Rubber ferrules also have a tendency to slip in the wet, on ice and other difficult surfaces. Rubber ferrules also wear easily, shortening the useful lifespan of the walking stick, and can be difficult to replace once worn.

Rubber ferrules are sometimes provided with grooves to improve the grip they offer, but gravel and other loose dirt can collect in the grooves, and again present a slipping hazard.

People who need a more stable walking stick sometimes use a larger ferrule, or use a "quad-cane" which splits into four tips at its base, each tip comprising its own ferrule.

These solutions are less effective on uneven surfaces and when the stick is used at an angle away from the vertical, as well as being unwieldy and difficult for the user to manoeuvre.

In light of this, a walking stick base which can adapt to uneven surfaces would be highly desirable.

Summary of the Invention

In pursuit of this aim, the present invention provides a foot for use at the end of an elongate support, such as a walking stick. The foot comprises a retaining member suitable for attachment to the end of the elongate support and a base pivotally connected to the retaining member. The foot further comprises an elastic member interposed between the retaining member and the base such that pivoting of the base relative to the retaining member compresses the elastic member between the retaining member and the base! whereby the resilience of the elastic member acts to resist such pivoting.

Thus, in accordance with the invention, the elastic member tends return the base to its default position in which the elastic member is uncompressed. Typically, in this position the lower surface of the base is substantially perpendicular to the elongate support. This simple arrangement ensures that the base is positioned predictably for the user, which aids stability of the support, in use.

The elongate support may be part of a walking stick, a crutch, a leisure hiking stick, a walking frame, or any other mobile support device. The elongate support may be part of a chair, wet chair, table or other structure. The elongate support may also be part of a scaffolding. The elongate support may frequently be made out of aluminium, but may also be made of iron, steel or any other suitable metal. The elongate support may also be made of non-metallic substances such as carbon, plastic, other polymers and the like. In embodiments of the invention the elongate support is tubular. In this case, the retaining member may be received within an end of the elongate support, in use In this way, the invention provides a foot which can be used with walking sticks, and which is capable of elastic movement with respect to the walking stick, such that the foot can adapt dynamically to changing terrain. The flexibility of the foot means that a wider base can be used than would otherwise be suitable for a walking stick, since the wider base will be able to tip" and so align with the surface it is placed upon, without the user having to reorient the walking stick. Hence the invention gives a user increased levels of grip on a number of different surfaces, and ensures that the grip remains substantially constant regardless of how the user is holding the walking stick.

The pivoting base allows the user to have the stick at angles to the floor, for example 45 degrees, whilst still ensuring the base is kept in full contact with the floor. A user can therefore, for example, place a walking stick with a foot according to the invention, far in front of their body while the user bends forward to retrieve an object from ground level.

With conventional walking stick designs, the grip provided by a ferrule would be greatly reduced in such circumstances, and so endanger the user.

The base may be connected directly or indirectly to the base. In embodiments of the invention, the base is connected to the retaining member by an attachment member.

Similarly, the elastic member may be compressed directly or indirectly by the retaining member and/or the base.

The pivotable connection between the retaining member and the base may take any suitable form. For example, the connection may take the form of a simple hinge.

Alternatively, the connection may take the form of a flexible member which allows relative pivoting of the retaining member and the base. In a presently preferred embodiment, the base is connected to the retaining member by a ball and socket joint.

In this case, the joint is relatively robust and allows pivoting between the base and retaining member about two axes. It will be noted that in this case the strength of the connection between the retaining member and the base is independent of the elastic member, i.e. the elastic member is not required to connect the base and retaining member.

The ball and socket joint may connect the attachment member to the base. In the presently preferred embodiment, the ball and socket joint connects the attachment member to the retaining member. Thus, the retaining member may comprise a socket and the attachment member may comprise a ball at an end thereof. The ball may be received within the socket of the retaining member to form the ball and socket joint. In particular, the retaining member may comprise a first part and a second part, each part having defined therein a cavity. The cavities may together form the socket, with the first and second parts held together by a tubular elongate support when the retaining member is located in the end of the elongate support, whereby to retain the ball in the socket. In this case, the tubular support acts to hold together the retaining member and thus the joint. This provides for particularly straightforward assembly of the foot and support. The retaining member may therefore be split into two halves which are constrained when they are pushed into the support tube, hence creating an interference fit during assembly. Such an arrangement provides a strong connection between the attachment member and the retaining member, since the ball of the attachment member cannot pop out of the socket of the retaining member unless the foot is placed under a force strong enough to break the support tube. However, this arrangement still allows a wide range of movement between the attachment member and the retaining member.

Ridges may be provided on the support-engaging surface of the retaining member to increase friction between the retaining member and the interior of the tubular support.

The ridges may be configured to provide greater resistance to removal of the retaining member from the tubular support than to insertion of the retaining member into the tubular support. The interior of the support tube may also be provided with ridges, such that the ridges of the retaining member mate with the ridges of the support tube, in use.

The retaining member, the attachment member and/or the base may be formed of metals such as aluminium, plastics, or any other suitably rigid material. The base may further comprise a deformable material such as rubber or elastomer, in order to provide increased friction when in contact with a surface. The base may also be shaped to increase friction or to better support the user, for example by providing ridges, bevelling, spikes, or other such features on the lower surface thereof.

The base may be removably attached to the attachment member, for example by means of a screw thread. A base which is removably attached is advantageous as it allows a user to remove and replace the base easily. The user can then replace worn-out bases without having to replace the entire foot. The user can also replace the base with a different base in order to cope with different conditions, for example by providing a walking stick with a base which comprises spikes, for use in muddy or icy conditions. An easily changed based is especially desirable for users who have conditions such as arthritis, which make manipulating objects difficult.

The foot may comprise a locking member which is inserted through holes defined in the attachment member and the base, in use, such that the base cannot rotate with respect to the attachment member. Such an arrangement may prevent the base becoming lose during use.

The elastic member may take any suitable form. In a presently preferred embodiment, the elastic member is in the form of a ring. The ring may be circular or have any other suitable shape. Conveniently, the ring may be located about the attachment member.

In this way, the elastic member can be replaced easily, by removing the base and sliding the ring off the attachment member. The elastic member may be made of rubber or another elastomer. The elastic member can be manufactured as a separate part and assembled into the design or by means of over moulding an elastic or other material directly onto the base.

The invention extends to a foot in combination with an elongate support, in particular where the elongate support is a walking stick.

Advantages of these embodiments are set out hereafter! and further details and features of each of these embodiments are defined in the accompanying dependent claims and

elsewhere in the following detailed description.

Brief Description of the Drawings

Various aspects of the teachings of the present invention, and arrangements embodying those teachings, will hereafter be described by way of illustrative example with reference to the accompanying drawings, in which: Figure 1 is a an exploded diagram showing a first walking stick foot according to the invention; Figures 2 to 5 are illustrations of part of one half retaining member of the foot of Figure 1; Figure 6 is an illustration of a first attachment member of the foot of Figure 1; Figures 7 to 9 are illustrations of a tirst base of the foot of Figure 1; Figures 10 and 11 are illustrations of an elastic member of the foot of Figure 1; Figures 12 and 13 are illustrations of a sleeve of the foot of Figure 1; Figure 14 shows the partially assembled foot of Figure 1; Figures 15 and 16 are illustrations of the assembled first foot of Figure 1; Figure 17 is an illustration of a second walking stick foot according to the invention; Figure 18 is an illustration of a third walking stick foot according to the invention; Figure 19 is an illustration of a third base of the foot of Figure 18; Figure 20 is a cross section of a fourth walking stick foot according to the invention; Figure 21 is a cross section of a fifth walking stick foot according to the invention; Figure 22 shows a sixth walking stick foot according to the invention; and Figure 23 is a cross section of the sixth walking stick foot according to the invention.

Detailed Description of Preferred Embodiments

Preferred embodiments of the present invention will now be described with particular reference to a walking stick.

Figure 1 is an exploded diagram showing a first foot 100 for a walking stick 200 according to the invention. The walking stick 200 comprises a hollow metal tube, which is typically made out of aluminium. The first foot 100 comprises two halves of a retaining member 110, a first attachment member 120, a first base 130, an elastic member 140 and a sleeve 150. The first foot 100 further comprises a pad 160, which is adhered to the bottom of the first base 130.

Figures 2 to 15 show more detailed illustrations of the components 110, 120, 130, 140, 150 of the first foot 100. Figures 2 to 5 show various views of one half retaining member 110. The half retaining member 110 comprises a peg 111 and a correspondingly sized receptacle 112. When two identical half retaining members 110 are placed together as indicated in Figure 1, they form a single, substantially cylindrical whole, with the peg 111 of each half retaining member 110 inserted into the receptacle 112 of the other half retaining member 110.

Each half retaining member 110 further comprises external ridges 113 and a first lip 114.

When a retaining member is assembled and inserted into the walking stick 200, the external ridges 113 are angled such that they present a shallow slope to the interior of the walking stick 200 during insertion, and so ease the insertion of the retaining member.

The first lips 114 prevent the retaining member from being inserted too far into the walking stick 200.

Once inside the walking stick 200, if the retaining member experiences a force that tends to pull it back out of the walking stick 200 again, then the external ridges 113 present a face which is substantially orthogonal to the interior surface of the walking stick 200, and as such the external ridges 113 will tend to "dig in" to the walking stick and resist the removal of the retaining member.

Finally, each half retaining member 110 comprises a cavity 115 such that when the retaining member is assembled it comprises a substantially spherical socket formed of the two cavities 115.

Figure 6 shows the first attachment member 120, which comprises a ball 121, a neck 122 and a rod 123. In use, the ball 121 is retained in the socket formed by the cavities 115 of two half retaining members 110. The ball 121 is enclosed within the socket such that it cannot fall out without the two half retaining members 110 being separated, but the ball 121 can still rotate within the socket with respect to the retaining member.

The rod 123 comprises a helical thread wrapped around the outside of the rod (not shown), so that the first base 130 can be attached to the first attachment member 120.

Figures 7 to 9 show the first base 130. Figure 9 is a cross section of the first base 130 through the line A-A illustrated in Figure 8. The first base 130 comprises a generally conical upper section 131 and a generally cylindrical lower section 132, and is provided with a hole 133 extending through the upper section and partially through the lower section. The hole 133 is provided on the inside with a helical thread so that the first base can be screwed into place on the rod 123 of the first attachment member 120.

Figures 10 and 11 show the elastic member 140. The elastic member 140 comprises a ring of elastomer material which, in use, sits around the neck 122 of thefirst attachment member 120.

Figures 12 and 13 show the sleeve 150. The sleeve 150 is placed around the walking stick 200 in use, so that it can protect the end of the walking stick 200 and the rest of the first foot 100 from damage due to impact during use. The sleeve 150 comprises a second lip 151, which catches on the first lips 114 of the half retaining members 110 and on the bottom of the walking stick 200, and so prevents the sleeve 150 from riding up the walking stick 200.

Figure 14 shows a partially assembled first foot 100, with the ball 121 of the first attachment member 120 resting in the cavity 115 of a half retaining member 110. The elastic member 140 is in place around the neck 122 of the first attachment member 120 and the first base 130 has been screwed onto the rod 123 of the first attachment member 120.

In use, the majority of the weight placed upon the first foot 100 is taken by the ball and socket assembly, that is the half retaining members 110 and the first attachment member 120, rather than the elastic member. The half retaining members 110 and the first attachment member 120 are both rigid and sturdy, and are not required to flex during use. As such they are hard wearing, and well suited to taking the repeated stresses that a user will inflict on the first foot 100 while walking with the aid of the walking stick 200.

Figures 15 and 16 show a fully assembled first foot 100, attached to a walking stick 200.

In Figure 16, the first base 130 has moved with respect to the walking stick 200. This is possible because the ball 121 rotates within the socket of the retaining member 110.

Therefore when the walking stick 200 is placed so that the stick is not normal to the plane of the surface on which the first foot rests, the first base 130 can pivot with respect to the walking stick and so maintain the entire pad 160 in maximum contact with on which the surface the first foot 100 has been placed. This would happen during routine use of the walking stick 200, such as when a user places the walking stick in front of them, at an angle, while walking, or when the walking stick is used on an uneven surface.

The first foot 100 can also pivot with the movement of the user, such that the first base 130 stays flat upon the ground while the user moves the walking stick 200 above it. This helps to increase the user's comfort by easing their walking motion.

When the first base 130 moves with respect to the walking stick 200, this causes the first aftachment member 120 to rotate with respect to the retaining member 110. In turn, the elastic member 140 is compressed between the lower surfaces of the retaining member 11 Oand the sleeve 150, and the upper surface of the first base 130. Therefore the elastic member 140 experiences a compression force, and deforms. Since the elastic member is constructed from an elastic material, it will tend to return to its original shape, and so will exert a force on the retaining member 110, the sleeve 150 and the first base 130 that will urge the first base 130 into a position in which the lower surface of the first base 130 is substantially normal to the longitudinal direction of the walking stick 200, as illustrated in Figure 15. Hence the first foot 100 is self-righting, in that it will tend to return to a particular orientation when not held out of that orientation by the forces exerted on the walking stick 200 and the first foot 100 by the user.

The elastic member 140 also resists the pivoting motion of the first base 130 as it is happening. This provides a gentle resistance to the motion of the walking stick 200 as it is placed upon the ground, and has the effect of dampening the force experience by the users hand, arm and shoulder. This reduces the strain experienced by the user while walking, helping the user to walk further, and more safely. Furthermore, the user can place a walking stick 200 provided with a first foot 100 further in front of their body than would be possible with a walking stick which comprised a conventional ferrule without risk of slippage. This means that the user can place the walking stick 200 where they need it to be for the most comfortable walking posture, further reducing strain on the user.

As the first base 130 is screwed into place on the first attachment member 120, it can be removed and replaced easily by the user. This makes changing an old base for a new one, once the old one has worn out, easy. Once the first base 130 is removed, the elastic member 140 can also be worked loose and replaced, which the user may wish to do if the elastic member 140 has begun to wear down, or lose its elasticity. The user may also want to substitute different types of base for use in different conditions, as described below.

Figure 17 shows a second base 134 in use as part of a second foot 101. The second base 134 is similar to the first base 130, and is also provided with a pad 160, except that the second base 134 has a greater diameter. The second base 134 may therefore offer increased stability for the user, particularly on substantially planar walking surfaces.

Figures 18 and 19 show a third base 135 in use as part of a third foot 102. The third base 135 comprises a plurality of spikes 136 which may provide increased grip for the user in icy, or muddy, conditions, for example.

During typical use it is possible for the base to experience a torque which will cause it to unscrew from the attachment member, for example when the user is turning and keeps the base on the ground as they turn themselves and the walking stick 200 above it.

Therefore some users may wish to impede rotation of the base with respect to the attachment member. This would make removing and replacing the base and the elastic member 140 more difficult, but would also help to prevent the base accidentally coming loose.

Figure 20 shows a cross section of a fourth foot 103, in which the first base 130 is provided with an insert 170. The first base 130 is moulded around the insert 170, and the insert 170 provides a coarser thread connection for the rod 123 and so impedes the rotation of the first base 130 with respect to the first attachment member 120. The insert is typically brass. The insert 170 may be of the type manufactured by Tappex®.

Figure 20 also shows a walking stick 200 which is provided with internal ridges 201, which matewith the external ridges 113 ofeach half retaining memberll0 in use, and hence help to retain the retaining member within the walking stick 200.

Figure 21 shows a cross section of a fifth foot 104, which comprises a fourth base 136, a second attachment member 124 and a locking plate 180. The fourth base 136 and the second attachment member 124 both comprise a hole, and during assembly, the second attachment member is screwed into place in the fourth base such that the two holes align. The locking plate 180 is then inserted through the hole in the fourth base 136 and the hole in the second attachment member 124. The fourth base 136 is therefore prevented from rotating with respect to the second attachment member 124, in use.

Figure 22 shows a walking stick 200 which is provided with a sixth foot 105. Figure 23 shows a cross section of the walking stick 200 and the sixth foot 105. The sixth foot 105 is substantially the same as the first foot 100, except in that it comprises a grip sock 161 in place of a pad 160. The grip sock is made of an elastic material, rubber in this case, and stretches over the first base 130. The grip sock is held in place by friction between the grip sock 161 and the first base 130, and as such does not require adhesive.

Therefore the grip sock can be easily interchanged in the event that it becomes worn out, or if the user requires a different size, shape or texture of grip sock for use on different surfaces.

Some users may wish always to use their stick such that the stick is rarely, if ever, placed at an angle where it is substantially normal to the plane of the surface upon which the base is resting. In such cases, the foot may be provided with an elastic member which is shaped so as to maintain the base in a "tipped" position. A similar result can be achieved by using a base which does not have rotational symmetry about the axis of the walking stick 200, for example by providing a wedge shaped pad 160 or grip sock 161.

The pad 160 or grip sock 161 comprises a high friction material in order to minimise slipping. Different embodiments according to the invention may use materials such as 3M® Bumpon® products or the Slip-Not Grip Fabrics manufactured by Eastex Products, Incaspartofthepad l6oorgripsockl6l.

In summary, embodiments of the present invention provide a foot 100 for use at the end of a support tube 200. The foot 100 comprises: a retaining member suitable 110 for insertion into the end of the support tube 200, the retaining member comprising a socket; an attachment member 120 which comprises a ball, the ball being retained within the socket such that the ball is free to rotate with respect to the retaining member 110; and a base 130 attached to the attachment member such that the base 130 extends beyond the support tube 200, in use. The device further comprises an elastic member 140 attached to the foot 100 such that the elastic member 140 tends to propel the attachment member 120 and base 130 assembly into a chosen orientation with respect to the retaining member 110.

Claims (1)

1. <claim-text>CLAIMS1. A foot for use at the end of an elongate support, the foot comprising: a retaining member suitable for attachment to the end of the elongate support; and a base pivotally connected to the retaining member, wherein the foot further comprises an elastic member interposed between the retaining member and the base such that pivoting of the base relative to the retaining member compresses the elastic member between the retaining member and the base, whereby the resilience of the elastic member acts to resist such pivoting.</claim-text> <claim-text>2. Afoot as claimed in claim 1, wherein the base is connected to the retaining member by an attachment member.</claim-text> <claim-text>3. A foot as claimed in claim 1 or 2, wherein the base is connected to the retaining member by a ball and socket joint.</claim-text> <claim-text>4. A foot as claimed in claim 2 and 3, wherein the ball and socket joint connects the attachment member to the base.</claim-text> <claim-text>5. A foot as claimed in claim 2 and 3, wherein the ball and socket joint connects the attachment member to the retaining member.</claim-text> <claim-text>6. A foot as claimed in claim 5, wherein the retaining member comprises a socket and the attachment member comprise a ball at an end thereof, the ball being received within the socket of the retaining member to form the ball and socket joint.</claim-text> <claim-text>7. A foot as claimed in claim 2 or any preceding claim dependent thereon, wherein the foot comprises a locking member which is inserted through holes defined in the attachment member and the base, in use, such that the base cannot rotate with respect to the attachment member.</claim-text> <claim-text>8. A foot as claimed in any preceding claim, wherein the elastic member is in the form of a ring.</claim-text> <claim-text>9. A foot as claimed in claim 8 when dependent directly or indirectly on claim 2, wherein the ring is located about the attachment member.</claim-text> <claim-text>10. Afoot as claimed in any preceding claim wherein the elongate support is tubular and the retaining member is received within an end of the elongate support, in use.</claim-text> <claim-text>11. A foot as claimed in claim 10 when dependent directly or indirectly on claim 6, wherein the retaining member comprises a first part and a second part, each part having defined therein a cavity, the cavities together forming the socket, and the first and second parts are held together by the tubular elongate support when the retaining member is located in the end of the elongate support, whereby to retain the ball in the socket..</claim-text> <claim-text>12. Afoot as claimed in any preceding claim in combination with an elongate support.</claim-text> <claim-text>13. Afoot as claimed in claim 12, wherein the elongate support is a walking stick.</claim-text>