Camming devices

Abstract

A camming device ( 10 ) comprises a stem ( 12 ), a spindle ( 16 ) mounted on the stem, at least two cam members ( 24,26 ) adapted to engage the walls of a crack or hole by their cam profiles pivotally mounted on the spindle and adapted for opposite pivotal movement from a closed position to an open position, means ( 28,30 ) to apply a force to each cam member to urge it to its open position, and means for pivoting the cams to the closed position, characterised in that the stem is mounted directly to the spindle.

1 . A camming device comprising a stem, a spindle mounted on the stem, at least two cam members adapted to engage the walls of a crack or hole by their cam profiles pivotally mounted on the spindle and adapted for opposite pivotal movement from a closed position to an open position, means to apply a force to each cam member to urge it to its open position, and means for pivoting the cams to the closed position, characterised in that the stem is mounted directly to the spindle.  
     
     
         2 . A camming device as claimed in  claim 1 , wherein the spindle extends either side of a location for one end of the stem.  
     
     
         3 . A camming device as claimed in  claim 2 , wherein the location for the stem end is preferably a through bore in a block.  
     
     
         4 . A camming device as claimed in  claim 3 , wherein the bore is stepped and a sleeve is fixed on the end of the stem to sit on the step of the bore when the stem is fed through the bore.  
     
     
         5 . A camming device as claimed in  claim 3 , wherein the bore is narrower in diameter than the sleeve, so that as the stem end bearing the sleeve is pulled through the bore, it is held tighter.  
     
     
         6 . A camming device as claimed in  claim 3 , wherein the block has an outer edge and its outer edge, where the stem emerges, is radiussed.  
     
     
         7 . A camming device as claimed in  claim 1 , wherein the end of the stem is fixed directly to the spindle by means of one of a welded and a soldered joint.  
     
     
         8 . A camming device comprising a stem, a spindle mounted on the stem, at least two cam members adapted to engage the walls of a crack or hole by their cam profiles pivotally mounted on the spindle and adapted for opposite pivotal movement from a closed position to an open position, means to apply a force to each cam member to urge it to its open position comprising a trigger and wires linking the trigger and each cam, and means for pivoting the cams to the closed position, characterised in that the wires pass through guides mounted on the stem.  
     
     
         9 . A camming device as claimed in  claim 8 , having one of a single stem, a looped and a U-shaped stem.  
     
     
         10 . A camming device as claimed in  claim 8 , wherein at least one guide for the wires is provided along the stem of the camming device.  
     
     
         11 . A camming device as claimed in  claim 8 , wherein guides have a through hole for each wire  
     
     
         12 . A camming device as claimed in  claim 8 , wherein guides have a hole for each pair of wires.  
     
     
         13 . A camming device as claimed in  claim 8 , wherein the guides are located axially on the stem by means of segments of coiled spring, which allow the guides to return to a preferred position during and after use.  
     
     
         14 . A camming device as claimed in  claim 13 , wherein one or more spring segments comprise an open pitch construction, which will allow the stem assembly to spring back to a normal alignment.  
     
     
         15 . A camming device as claimed in  claim 13 , wherein the spring segments are formed form one continuous piece with the guides located around its diameter and along its length.  
     
     
         16 . A camming device as claimed in  claim 8 , wherein the guides are formed as larger coils between smaller coils of a coiled spring about the stem of the camming device.  
     
     
         17 . A camming device as claimed in  claim 8 , wherein the stem is mounted directly to the spindle.  
     
     
         18 . A camming device as claimed in  claim 8 , wherein the spindle extends either side of a location for one end of the stem.  
     
     
         19 . A camming device as claimed in  claim 18 , wherein the location for the stem end is a through bore in a block.  
     
     
         20 . A camming device as claimed in  claim 19 , wherein the bore is stepped and a ferrule or sleeve is fixed on the end of the stem to sit on the step of the bore when the stem is fed through the bore.  
     
     
         21 . A camming device as claimed in  claim 19 , wherein the bore is narrower in diameter than the ferrule, so that as the stem end bearing the ferrule or sleeve is pulled through the bore, it is held tighter.  
     
     
         22 . A camming device as claimed  claim 19 , wherein the block has an outer edge, where the stem emerges, which is radiussed.  
     
     
         23 . A camming device as claimed in  claim 8 , wherein the end of the stem is fixed directly to the spindle by means of a welded or soldered joint.  
     
     
         24 . A camming device as claimed in  claim 1 , wherein the means to apply a force to each cam includes a trigger and a trigger wire connecting the cam to the trigger, the trigger wire being formed in two parts, a first rigid part being connected to the cam and a second flexible part connected to the trigger, the rigid wire part being formed or provided with a means for joining the second part thereto along a common axis.  
     
     
         25 . A camming device as claimed in  claim 24 , wherein the rigid wire is formed with coils at one end having an axis common with a straight part of the wire and for one end of the flexible wire part to be insertable into those coils to share that common axis.  
     
     
         26 . A camming device as claimed in  claim 24 , wherein one end of the rigid wire part is formed as a tube to receive one end of the flexible wire part to share a common axis.