US 5,243,874 AGranted

Method and apparatus for telescopically assembling a pair of elongated members

AssigneePittsburgh Tubular Shafting, Inc.

InventorsRobert A. Wolfe, Lester G. Finney

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Abstract

A pair of telescoping members include interconnecting end portions having a preselected configuration that facilitates the insertion of one tubular end portion into the other tubular end portion. The surface configuration of the interconnecting end portions is complementary so that the surfaces on an inner member engage the surfaces on the outer member to permit the transmission of rotation from one telescoping member to the other while permitting relative longitudinal movement therebetween. The inner and outer connecting members are spaced apart to form an annulus therebetween and provide a degree of tolerance greater than the tolerance provided with conventionally machined telescoping connecting end portions. The tolerance is taken up by the injection of a thermosetting resinous material at an elevated temperature into the annulus, completely filling the annulus. The thermosetting material when reduced to a lower operating or ambient temperature shrinks a preselected degree to form an elastomeric sleeve adhered to the inner surface of the outer connecting member. The cross-sectional area of the elastomeric sleeve is less than the cross-sectional area of the annulus between the connecting members. The difference in the cross-sectional area provides the connection of the telescoping members with a tolerance that is equal to the amount of shrinkage of the elastomeric sleeve. Thus, the provision of the elastomeric sleeve permits precise control of the tolerance between the telescoping members.

Claims20

Dependent claims

A telescoping assembly of elongated members comprising,

an elongated first member having a tubular end portion with an internal surface forming a cavity, said internal surface having a contour of a preselected configuration,
an elongated second member having a tubular end portion with an external surface having a contour of a configuration complementary to said preselected configuration of said first member internal surface,
said second member end portion telescopically positioned within said cavity of said first member end portion to nonrotatably connect said internal and external surfaces for longitudinal movement of said first and second members with respect to each other,
said second member external surface spaced from said first member internal surface forming opposing surfaces with an annulus of a preselected cross-sectional area between said telescopically positioned tubular end portions,
a thermosetting resinous material injected at an elevated temperature into said annulus to initially completely fill said annulus and contact said opposing surfaces,
said thermosetting resinous material responding to a reduction in the elevated temperature to a reduced temperature by cooling to form a cured sleeve cast in place by the configuration of said opposing surfaces,
said cured sleeve being formed in place between said first and second members to include an outer surface complementary in configuration with said first member internal surface and an inner surface complementary in configuration with said second member external surface,
said sleeve outer surface bonded to said first member internal surface and said sleeve inner surface being radially spaced from said second member external surface for telescopic, slidable movement of said second member relative to said first member with said sleeve retained fixed within said first member, and
said cured sleeve having a cross-sectional area less than the cross-sectional area of said annulus and complementary in configuration with said opposing surfaces to provide a uniform tolerance in the telescopical, nonrotational engagement of said tubular end portions controlled by the amount of shrinkage of said thermosetting resinous material.

6 more elements

A method for telescopically and nonrotatably connecting a pair of elongated members comprising the steps of,

positioning a tubular end portion of an elongated inner member oppositely of a tubular end portion of an elongated outer member,
inserting the end portion of the inner member into the end portion of the outer member,
concentrically positioning the inner member within the outer member for relative longitudinal and nonrotational movement,
maintaining the inner and outer members in concentric spaced relation to form opposing surfaces with an annulus of a preselected cross-sectional area between the inner and outer members,
filling the annulus with a thermosetting resinous material at an elevated temperature,
reducing the temperature of the thermosetting resinous material in the annulus to shrink the material to form between the inner and outer members a cured sleeve having a configuration complementary with the configuration of the opposing surfaces of the inner and outer members and a cross-sectional area less than the cross-sectional area of the annulus as determined by the degree of shrinkage of the thermosetting resinous material,
bonding the sleeve to the outer member with the inner member being movable longitudinally within the sleeve and outer member by radially spacing an external surface of the inner member from an inner surface of said sleeve, and
nonrotatably engaging the inner member to the outer member with a preselected tolerance as provided by the amount of shrinkage of the thermosetting resinous material.

5 more elements

A steering tube assembly comprising,

a pair of telescoping members having end portions slidably engaged to one another,
said end portions having complementary opposed surfaces of a preselected contour for nonrotatably engaging said telescoping members,
said complementary opposed surfaces being spaced a preselected distance apart to form a void therebetween,
a thermosetting elastomeric sleeve formed in place in the void between said complementary opposed surfaces of said end portions to telescopically and nonrotatably connect said end portions for co-rotation of said telescoping members with a minimum amount of relative rotation therebetween,
said elastomeric sleeve having inner and outer surfaces complementary in configuration with said complementary opposed surfaces of said telescoping members, and
said elastomeric sleeve being radially expandable and contractible between a first position at an elevated temperature substantially filling said void and a second position at an ambient temperature where the sleeve uniformly shrinks in size to a configuration remaining complementary with said complementary opposed surfaces to occupy a portion of the void to provide a desired tolerance in the engagement of said telescoping members whereby an external surface of an inner telescoping member is radially spaced form an inner surface of said sleeve.

3 more elements

Dependencies are inferred from the claim text.