Head for bore gauge

Claim 2

A head for a bore gauge having a movable member therein adapted to produce an indication of measurement corresponding to the extent of displacement of said member, said head being characterised by a body (18), connecting means for operatively connecting said body to said gauge, a transfer rod (56) mounted for limited longLtudinal movement in said body and drivingly connected at one end to said member (48), a bore-engaging sensing member (74) movably mounted to the distal end of said body and drivingly connected to the other end of said rod, an adjustable bore-engaging element (76) mounted to the distal end of said body on the opposite side of said head in diametrical alignment with said sensing member, manually actuated rack and pinion means (85,88) operatively associated with said element for extending and retracting said element diametrically to and away from said body, and, centralising means (112) connected to said body for engaging the walls of said bore and positioning said sensing members and said element along the diameter of said bore.

Claim 3

A head according to claim 1, characterised in that said rack and pinion means includes rack teeth (88) formed lengthwise of said element (76) parallel to the path of travel thereof and a pinion (85) rotatably mounted in the distal end of said body and in mesh with said rack teeth, said pinion being manually rotatable from said distal end.

Claim 4

A head according to claim 2, characterised by locking means mounted to said body and engageable with said element for locking said element at a selected position, said locking means including a wedge (98) mounted in said distal end adjacent said element and engageable therewith, and a screw (102) extending through said wedge and threaded to said body, whereby said wedge may be selectively tightened against said element and loosed therefrom.

Claim 5

A head according to claim 3, characterised in that said wedge is formed with an element-engaging face (108) having at least one groove (111) defining at least a pair of lands in position to engage said element, and spring means (110) being operatively mounted between said wedge and said body for normally urging said wedge into a loosed position.

Claim 6

A head according to claim 1 characterised in that said other end of said transfer rod is formed with a diagonally extending V-groove (72), said sensory member being resiliently and pivotally mounted to said body and including a spherical portion (58) seated in said groove whereby any pivotal movement of said sensing member is converted to a linear movement of said rod, and wherein a support member is mounted to said body transversely of said rod and engages said rod along one side thereof adjacent said other end and opposite said groove to provide sliding support for said rod, said rod being formed with a generally flat face (64) along said one side, said face being formed with a longitudinal groove (66) and a pair of spaced parallel narrow longitudinal ribs (68, 70) slidably engaging said support member, said support member being a rigid cylindrical pin (62).

Claim 7

A head according to claim 5 characterised by a first hard ball contact (74) mounted to said sensory member in position to engage said bore and diametrically opposite said adjustable element, a second hard ball contact (92) at the outer end of said adjustable element in position to engage said bore and diametrically opposite said first ball contact, and a leaf spring (38) connecting said sensory member to said body, said leaf spring extending generally parallel to said rod and in position to deflect to and away from said rod.

Claim 8

A head according to claim 1 characterised in that said centraliser means (112) includes a U-shaped arm having a pair of paralled legs (11 and 116) and a cross-piece (118) at one end thereof, pivot means connecting the other end of said legs to said body with said legs extending generally parallel to said rod and along opposite sides of said body and with said cross-piece disposed proximately to the distal end of said body, and spring means between said arm and said body urging said one end of said arm away from the distal end of said body.

Claim 9

A head according to claim 7 characterised in that said arm is formed with a groove (138, 140) in each leg thereof at said one end and extending transversely of said legs, a centralising ball (134, 136) mounted for limited transverse movement in each of said grooves, each of said centralising balls having a portion thereof extending outwardly of its respective groove to simultaneously bear against said body and said bore when said head is within said bore, said centralising balls and said first and second ball contacts being disposed in the same plane, said body including a hardened metal track (142, 144) adjacent each of said centralising balls for engagement therewith, there being stop means operatively connected to said head for limiting the movement of said arm about said pivot means, and a semi- cylindrical groove formed lengthwise in each face of said V-groove to define a pair of spaced parallel semi-cylindrical grooves along which said spherical portion is adapted a to move.

Claim 10

A head for a bore gauge having a movable member therein adapted to produce an indication of measurement corresponding to the extent of displacement of said member, said head being characterised by a body, connecting means for operatively connecting said body to said gauge, a transfer rod mounted for limited longitudinal movement in said body and drivingly connected at one end to said member, a bore engaging sensing member movably and resiliently mounted to the distal end of said body and at one side thereof and drivingly connected to the other end of said rod, an adjustable bore-engaging element mounted to the distal end of said body on the opposite side of said head in diametrical alignment with said sensing member, a U-shaped centralising arm having a pair of parallel legs and a cross-piece at one end thereof, pivot means connecting the other ends of said legs to said body with said legs extending generally parallels to said rod and along opposite sides of said body and satd element and with said cross-piece disposed proximately the distal of said body, spring means connected between said arm and said body urging said one end of said arm away from the distal end of said body, said arm being formed with a groove in each leg thereof at said one end and extending transversely of said legs, and a centralising ball mounted for limited transverse movement in each of said grooves, each of said centralising balls having a portion thereof extending outwardly of the respective groove to simultaneously bear against said body and said bore when said head is within said bore.

Claim 11

A head for a bore gauge having a movable member therein adapted to produce an indication of measurement corresponding to the extent of displacement of said member, said head being characterised by a body, connecting means for operatively connecting said body to said gauge, a transfer rod mounted for limited longitudinal movement in said body and drivingly connected at one end to said member, a bore engaging sensing member movably and resiliently mounted to the distal end of said body and at one side thereof and drivingly connected to the other end of said rod, an adjustable bore-engaging element mounted to the distal end of said body on the opposite side of said head in diametrical alignment with said sensing member, a U-shaped centralising arm having a pair of parallel legs and a cross-piece at one end thereof, pivot means connecting the other ends of said legs to said body with said legs extending generally parallels to said rod and along opposite sides of said body and satd element and with said cross-piece disposed proximately the distal of said body, spring means connected between said arm and said body urging said one end of said arm away from the distal end of said body, said arm being formed with a groove in each leg thereof at said one end and extending transversely of said legs, and a centralising ball mounted for limited transverse movement in each of said grooves, each of said centralising balls having a portion thereof extending outwardly of the respective groove to simultaneously bear against said body and said bore when said head is within said bore.

Claim 12

A head according to claim 9 characterised in that said body includes a hardened metal track adjacent each of said centralising balls for engagement therewith, stop means is operatively connected to said head for limiting the movement of said arm about said pivot means, said other end of said transfer rod being formed with a diagonally extending V-groove, said sensory member being pivotally mounted to said body and including a spherical portion seated in said groove whereby any pivotal movement of said sensing member is converted to a linear movement of said rod, a support member being mounted to said body transversely of said rod and engaging said rod along one side thereof adjacent said other end and opposite said groove to provide sliding support for said rod, said rod being formed with a generally flat face along said one side, said face being formed with a longitudinal groove and a pair of spaced parallel narrow longitudinal ribs slidably engaging said support member, said support member being a rigid cylindrical pin, a first hard ball contact being mounted to said sensory member in position to engage said bore and diametrically opposite said adjustable element, a second ball contact being at the outer end of said adjustable element in position to engage said bore and diametrically opposite said first ball contact, a leaf spring connecting said sensory member to said body, said leaf spring extending generally parallel to said rod and in position to deflect to and away from said rod, said centralising balls and said first and second ball contacts being disposed in the same plane and a semi-cylindrical groove being formed lengthwise in each face of said V-groove to define a pair of spaced parallel semi-cylindrical grooves along which said spherical portion is adapted to move.