Walking aid

Abstract

A walking aid comprises a shaft and a foot assembly, in which the foot assembly includes in combination a sleeve member and a foot member adapted for relative axial sliding movement and including resilient movement-restraint means, the sleeve member being adapted for attachment to the shaft and including grip means for inhibiting or preventing removal from the shaft once attached thereto. The resilience may be adjustable and the foot member is preferably free to swivel within the sleeve member. The assembly may also be used as a castor, for use for example in shopping trolleys.

What is claimed is:  
     
         1 . A walking aid, comprising: 
 a shaft; and    a foot assembly attached to the shaft that includes in combination a sleeve member and a foot member, said sleeve and foot members including means to accommodate relative axial sliding movement and spring means adapted to resiliently restrain said sliding movement, said spring means including grip means for inhibiting removal of the sleeve member from the shaft after attachment.    
     
     
         2 . The walking aid according to    claim 1   , wherein the resilient movement-restraint force of said spring means is adjustable.  
     
     
         3 . The walking aid according to    claim 1   , wherein the foot member comprises: 
 a base element having a shoe formed from a material selected from the group including rubber and plastics, the base element being connected to a neck member which is journalled in the sleeve member with a compression spring therebetween; and    wherein the neck member is provided at its upper distal end with a screw thread to receive a retaining and resilience-adjustment nut.    
     
     
         4 . The walking aid according to    claim 1   , wherein the grip means comprises: 
 a resiliently-compressible element associated with the sleeve member for force-fitting within the shaft, whereby the sleeve member is retained within the shaft by friction forces acting between the resiliently-compressible member and the internal wall of the shaft.    
     
     
         5 . The walking aid according to    claim 4   , wherein the grip means comprises: 
 an element adapted to permit the sleeve member to be slidingly inserted within the shaft but which expands radially to assume a jamming position on attempted withdrawal thereof.    
     
     
         6 . The walking aid according to    claim 5   , wherein the sleeve member has an annular groove formed in the external surface thereof, and further comprising: 
 an expandable ring selected from the group including an O ring and a snap-ring wherein the expandable ring is formed from a material selected from the group including rubber and plastics, the expandable ring being carried in said groove and said groove having a sloping wall which urges the ring to expand to jam against the shaft wall on relative movement between the sleeve member and shaft in a direction of movement whereby the sloping wall is the trailing wall.    
     
     
         7 . The walking aid according to    claim 1   , wherein the foot member is free to rotate axially within the sleeve member.  
     
     
         8 . The walking aid according to    claim 1   , wherein the sleeve member is cylindrical in cross section and has an enlarged-diameter lower end flange defining an annular shoulder, the sleeve member having a through-bore which has an enlarged-diameter part at the lower end and carrying a pair of external annular grooves, and in which the foot member is a cylindrical bar having a lower end of maximum diameter and formed with an axial cavity, a first intermediate zone of reduced diameter, a second intermediate zone of further reduced diameter and defining a shoulder and a screw-threaded upper end, the diameter of said first intermediate zone being such that it will slide within the enlarged-diameter bore of the sleeve member and the diameter of said second intermediate zone being such that it will slide within the reduced-diameter bore of the sleeve member, a compression spring being accommodated in the annular gap between the second intermediate zone of the foot member and the enlarged-diameter bore of the sleeve member, and resiliently expandable rings being carried from said grooves and selected from the group including O rings and snap rings.  
     
     
         9 . The walking aid according to    claim 8   , wherein the sleeve member defines additional bore zones between the sleeve member and the first and second zones of reduced diameter of the foot member, the additional bore zones accommodating bushes which assist sliding movement of the foot member within the sleeve member.  
     
     
         10 . The walking aid according to    claim 8   , wherein the lower annular groove of the sleeve member is formed with a chamfer to the upper wall, wherein the expandable ring contained in the groove is constrained by friction against the inner wall of the shaft, on any attempt being made to withdraw the assembly from within the shaft, to travel up the chamfered surface to expand the ring into a jamming relationship with the shaft, thereby preventing removal of the assembly from the shaft.  
     
     
         11 . A foot assembly for attachment to a shaft of a tubular walking aid, the foot assembly comprising in combination a sleeve member and a foot member adapted for relative axial sliding movement and including spring means resiliently to restrain said sliding movement, the sleeve member including grip means operative to oppose removal from the tubular leg once attached thereto.  
     
     
         12 . A walking aid comprising a shaft and a foot assembly in which the foot assembly includes a ground-contacting ferrule, wherein said foot assembly comprises relatively axially-slidable cylindrical sleeve and neck members and spring means for resiliently restraining sliding movement between said sleeve and neck members, said neck member being journalled in said sleeve member for relative axial rotation, whereby said ground-contacting ferrule is axially rotatable with respect to said shaft to accommodate twisting movement between a user of the walking aid and the ground in use.  
     
     
         13 . The walking aid according to    claim 12   , wherein bushes are provided between said neck and sleeve members to assist relative sliding and rotational movement.  
     
     
         14 . The walking aid according to    claim 15    wherein the spring means is adjustable to vary the resilient restraining force.  
     
     
         15 . The walking aid according to    claim 12   , wherein the spring means comprises a compression spring.  
     
     
         16 . The walking aid according to    claim 15   , wherein the compression spring is disposed about the neck member and retained by a locknut which limits the relative sliding movement in the expansion direction of the compression spring by engagement with the sleeve member.  
     
     
         17 . A foot assembly for attachment to the shaft of a walking aid, comprising: 
 a ground-contacting ferrule that includes relatively axially-slidable cylindrical sleeve and neck members and spring means for resiliently restraining sliding movement between said sleeve and neck members, said neck member being journalled in said sleeve member for relative axial rotation, whereby said ground-contacting ferrule is axially rotatable with respect to said shaft to accommodate twisting movement between the user and the ground in use.    
     
     
         18 . A walking aid apparatus, comprising: 
 a handle portion; and    a shaft portion connected to the handle and including a ground-contacting ferrule, the shaft incorporating relatively rotatable telescopic elements and spring means acting between said elements resiliently to restrain relative compression movement of said elements, in which the spring means and at least one element have bearing surfaces which comprise sliding friction-reducing materials, whereby rotation between the handle portion and the ferrule accommodates twisting movement as between the user and the ground in a controlled manner.    
     
     
         19 . The apparatus according to    claim 18   , wherein the bearing surface of said at least one element is integral with the element and is in direct rotationally-slidable contact with the spring means.  
     
     
         20 . The apparatus according to    claim 18   , wherein a friction-reducing element is interposed between said at least one element and said spring means.  
     
     
         21 . The apparatus according to    claim 20   , wherein the friction-reducing element is formed from an engineering plastics material.  
     
     
         22 . The apparatus according to    claim 20   , wherein said friction-reducing element comprises an annular washer.  
     
     
         23 . The apparatus according to    claim 22   , wherein said washer is configured as a cup washer, the cup comprising the spring-facing surface and a peripheral wall to encompass the extremity of the spring means.  
     
     
         24 . The apparatus according to    claim 18   , wherein said spring means is selected from the group including a helical spring, a pneumatically-controlled strut, a hydraulically-controlled strut, and a resilient elastomeric material.  
     
     
         25 . The apparatus according to    claim 18   , wherein said spring means is incorporated into the apparatus by the means selected from the group including direct attachment to said ferrule and formed integrally with said ferrule.  
     
     
         26 . The apparatus according to    claim 18   , wherein said spring means is pre-loaded so that, when in the fully-extended position as received within the telescopically-mounted elements, the spring means is partially compressed.  
     
     
         27 . The apparatus according to    claim 18   , wherein said apparatus includes cylindrical bushes journalled between said telescopic elements.  
     
     
         28 . The apparatus according to    claim 18   , wherein said telescopic elements comprise inner and outer elements, said inner element having an inner co-axial neck portion of reduced diameter, and an annular gap being defined between the neck portion and the outer element, the gap accommodating the spring means.  
     
     
         29 . The apparatus according to    claim 28   , wherein at least one of the outer element, shaft, and handle portions includes a facing edge that is provided with a chamfer.  
     
     
         30 . The apparatus according to    claim 18   , wherein said telescopic elements comprise inner and outer elements, said inner element having an inner end face which bears on one end of the spring means.  
     
     
         31 . The apparatus according to    claim 18   , wherein the telescopic elements and spring means constitute a sub-assembly which is carried in the direction selected from the group including towards the ferrule end and towards the handle portion end of the apparatus.  
     
     
         32 . The apparatus according to    claim 18   , wherein at least one of the telescopic elements is adapted for engagement with a connector part configured for attachment to a ferrule and for connection with an element selected from the group including a hollow end portion of the walking aid shaft and a solid end portion of the walking shaft.  
     
     
         33 . In combination for use with walking aid apparatus according to    claim 18   , telescopic relatively rotatable elements and spring means acting between seats of said elements resiliently to restrain relative compression movement, in which the bearing surfaces of the spring means and at least one seat comprise sliding friction-reducing materials, the combination being adapted for engagement with a connector part configured for connection to an element selected from the group including a hollow end portion of the walking aid shaft and a solid end portion of the walking shaft.  
     
     
         34 . A sub-assembly for attachment to a walking aid apparatus, comprising: 
 relatively rotatable telescopic elements; and    a spring means acting between seats of said elements resiliently to restrain relative compression movement, the spring means having bearing surfaces and at least one seat that incorporates sliding friction-reducing materials.    
     
     
         35 . A sub-assembly according to    claim 34   , wherein one of the telescopic elements is adapted for engagement with a connector part configured for connection with an element selected from the group including a hollow end portion of the walking aid shaft and a solid end portion of the walking shaft.  
     
     
         36 . A sub-assembly according to    claim 34   , further including a ground-contacting ferrule attached to the sub-assembly.