Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
453 words
Apparatus for placing a fastener of the type comprising a threaded first part which is pulled towards and/or into a second part to place the fastener, which apparatus comprises: a body member; a threaded member for threadedly engaging with the threaded first part of a fastener to be placed, said threaded member being rotatable and reciprocable with respect to the body member; a lead-screw device comprising a first element and a second element in threaded engagement with each other, the first element being arranged to be rotationally driven, and the second element being drivingly connected to the threaded member whereby the threaded member may be rotated and reciprocated by the second element; an abutment member for abutting the second part of the fastener when the threaded member is engaged with the first part of the fastener, the abutment member abutting the second part of the fastener when the said second part and the body member are drawn towards each other by rotation of the threaded member in a sense appropriate to advance the threaded member into threaded engagement with the first part of the fastener; rotation-stopping means, actuated by engagement of the abutment member with the second part of the fastener as aforesaid, to stop rotation of the second element of the lead-screw device whereby continued rotation of the first element in the said appropriate sense causes relative rotational and axial movement of the first and second elements of the lead-screw device and longitudinal movement of the threaded member relative to the body member and the abutment member in a first direction to draw the first and second parts of the fastener towards each other; a first torque-limiting rotary connection between the first and second elements of the lead-screw device; and a second torque-limiting rotary connection between the second element of the lead-screw device and the body member; the relationship between the torque-limiting rotary connections being such that when the first element of the lead-screw device is rotationally driven in the appropriate sense to engage the threaded member with the first part of the fastener, the torque limit sustained by the first connection is higher than that sustained by the second connection so that the threaded member rotates to engage the first part of the fastener until the actuation of the rotation-stopping means as aforesaid; and such that when the first element of the lead-screw device is rotationally driven in the opposite sense, the torque limit sustained by the first connection is lower than that sustained by the second connection so that the first element of the leadscrew device rotates with respect to the second element and causes longitudinal movement of the threaded member in a second direction opposite to the first direction.
Claim 2
Dependent Claim
453 words
Apparatus for placing a fastener of the type comprising a threaded first part which is pulled towards and/or into a second part to place the fastener, which apparatus comprises: a body member; a threaded member for threadedly engaging with the threaded first part of a fastener to be placed, said threaded member being rotatable and reciprocable with respect to the body member; a lead-screw device comprising a first element and a second element in threaded engagement with each other, the first element being arranged to be rotationally driven, and the second element being drivingly connected to the threaded member whereby the threaded member may be rotated and reciprocated by the second element; an abutment member for abutting the second part of the fastener when the threaded member is engaged with the first part of the fastener, the abutment member abutting the second part of the fastener when the said second part and the body member are drawn towards each other by rotation of the threaded member in a sense appropriate to advance the threaded member into threaded engagement with the first part of the fastener; rotation-stopping means, actuated by engagement of the abutment member with the second part of the fastener as aforesaid, to stop rotation of the second element of the lead-screw device whereby continued rotation of the first element in the said appropriate sense causes relative rotational and axial movement of the first and second elements of the lead-screw device and longitudinal movement of the threaded member relative to the body member and the abutment member in a first direction to draw the first and second parts of the fastener towards each other; a first torque-limiting rotary connection between the first and second elements of the lead-screw device; and a second torque-limiting rotary connection between the second element of the lead-screw device and the body member; the relationship between the torque-limiting rotary connections being such that when the first element of the lead-screw device is rotationally driven in the appropriate sense to engage the threaded member with the first part of the fastener, the torque limit sustained by the first connection is higher than that sustained by the second connection so that the threaded member rotates to engage the first part of the fastener until the actuation of the rotation-stopping means as aforesaid; and such that when the first element of the lead-screw device is rotationally driven in the opposite sense, the torque limit sustained by the first connection is lower than that sustained by the second connection so that the first element of the leadscrew device rotates with respect to the second element and causes longitudinal movement of the threaded member in a second direction opposite to the first direction.
Claim 3
Dependent Claim
88 words
Apparatus as claimed in claim 1, in which said second torque-limiting rotary connection sustains substantially the same torque limit upon rotation of the first element of the lead-screw device in either sense, and the first torque-limiting rotary connection sustains a higher torque limit than the said same torque limit upon rotation of the first element of the lead-screw device in said one sense and sustains a lower torque limit than said same torque limit upon rotation of the first element of the lead-screw device in said opposite sense.
Claim 4
Dependent Claim
55 words
Apparatus as claimed in claim 1, in which the said second torque limiting rotary connection sustains a lower torque limit upon rotation of the first part of the lead-screw device in the said appropriate sense and sustains a higher torque limit upon rotation of the second part of the lead-screw device in said opposite sense.
Claim 5
Dependent Claim
91 words
Apparatus as claimed in claim 3, in which the said second torque limiting device comprises two interengaging sets of teeth having sloping faces, and means for urging the two sets of teeth resilienTly towards each other, those faces which are urged into contact with each other upon rotation of the first element of the lead-screw device in the said appropriate sense being less steeply sloping than those teeth which are urged into contact with each other upon rotation of the first element of the lead-screw device in the said opposite sense.
Claim 6
Dependent Claim
55 words
Apparatus as claimed in claim 3, in which the said first torque limiting rotary connection comprises a first surface carried by the first element of the lead-screw device, a second surface carried by the second element of the lead-screw device, and means for urging the first and second surfaces into frictional contact with each other.
Claim 7
Dependent Claim
31 words
Apparatus as claimed in claim 5, in which the urging means comprises a resilient spring and one of the first and second surfaces is provided by a surface of the spring.
Claim 8
Dependent Claim
76 words
Apparatus as claimed in claim 5, in which the first and second surfaces are urged into frictional contact with each other as aforesaid by axial movement of the first element of the lead-screw device relative to the second member in the said second direction, and the means for urging the first and second surfaces into frictional engagement with each other comprises the first and second elements of the lead-screw device and the second torque limiting connection.