Indexing arrangement

Claim 2

An indexing arrangement ensuring precise, rapid and repetitive positioning of two parts with respect to each other, the first one being capable of displacement by gliding upon the second, either in translation, or in rotation, or in combination of both, of a kind comprising a cylindrical cavity located in the second fixed part and perpendicular to the plane of sliding and terminating in it, one or more cylindrical cavities being located in the first movable part and of a diameter size as close as possible to that of the fixed part cavity, also perpendicular to the plane of sliding and ending on the latter there being a cylindrical pin provided with an insertion means for entry into one of the cylindrical cavities of the movable part when this cavity is approximately aligned with the cylindrical cavity of the fixed part into which this pin may slide with some play, in which the length of entry of the pin is limited to a predetermined value by a stop mounted on one of the parts, the pin comprising an expansible tubular envelope housing an elastic means radially dilating in both cavities of the fixed and movable parts under the influence of axial compression caused by the entry means when the length of entry is being stopped by the stop, this radial dilation taking place until there is interlocking of the fixed part of the envelope and the movable part.

Claim 3

An arrangement according to claim 1, characterized by said entry means being mounted on the fixed part and carrying the cylindrical pin, the expansible tubular envelope being provided with a flange resting upon a shoulder of the fixed part after the pin has entered a cavity of the movable part, said shoulder of the fixed part then providing a reacting surface to the compressive force of the entry means.

Claim 4

An indexing arrangement according to claim 1, characterized by the expansible tubular envelope being hermetic and holding a fluid which may be compressed by introduction of a plunging piston into said tubular envelope.

Claim 5

An indexing arrangement according to claim 3, characterized by the expansible tubular envelope being hermetic and holding a fluid which may be compressed by introduction of a plunging piston into said tubular envelope.

Claim 6

An indexing arrangement according to claim 3, characterized by the plunging piston being fixed at one end portion to the pin''s entry means and being operative when the pin touches the stop, said piston carrying said envelope at its other end portion.

Claim 7

An indexing apparatus for relatively positioning first and second members which are slidably displaceable with respect to each other, comprising: a first cylindrical cavity formed in said first member and extending substantially perpendicular to the surface thereof over which said second member is relatively slidably displaceable; a second cylindrical cavity formed in said second member and extending substantially perpendicular to the surface thereof over which said first member is relatively slidably displaceable, said second cavity having substantially the same diameter as the diameter of said first cavity; a cylindrical member comprising a radially elastically expandable tubular envelope; insertion means for inserting said expandable envelope into said first and second cavities and positioning said envelope to bridge the interface of said cavities; and force exerting means exerting a radial force on said envelope in its bridging position to expand said envelope against the walls of said cavities and to thereby slidably displace said first and second members with respect to each other and to urge said cavities into axial alignment with each other, said force exerting means including a plurality of elastic washers contained in said envelope and means exerting an axial compressive force on said washers to cause said washers to exert a radial force on said envelope.

Claim 8

An indexing apparatus for relatively positioning first and second members which are slidably displaceable with respect to each other, comprising: a first cylindrical cavity formed in said first member and extending substantially perpendicular to the surface thereof over which said second member is relatively slidably displaceable; a second cylindrical cavity formed in said second member and extending substantially perpendicular to the surface thereof over which said first member is relatively slidably displaceable, said second cavity having substantially the same diameter as the diameter of said first cavity; a cylindrical member comprising a radially elastically expandable tubular envelope; insertion means for inserting said expandable envelope into said first and second cavities and positioning said envelope to bridge the interface of said cavities; and force exerting means exerting a radial force on said envelope in its bridging position to expand said envelope against the walls of said cavities and to thereby slidably displace said first and second members with respect to each other and to urge said cavities into axial alignment with each other, said force exerting means including a plurality of elastic washers contained in said envelope and means exerting an axial compressive force on said washers to cause said washers to exert a radial force on said envelope.

Claim 9

An indexing apparatus according to claim 6, wherein said cylindrical member further comprises a cylindrical pin to which said envelope is fixed, said insertion means being mounted on said first member and carrying said cylindrical pin, and wherein said expandable envelope is provided with a flange which rests on a shoulder of said first member upon insertion and positioning of said envelope in said cavities, said shoulder providing a surface against which the compressive force of said force exerting means acts.