US3688381A

US3688381A - Apparatus for installing bushings

Info

Publication number: US3688381A
Application number: US19672A
Authority: US
Inventors: Robert H Shiflet
Original assignee: Rohr Inc
Current assignee: Rohr Inc
Priority date: 1970-03-16
Filing date: 1970-03-16
Publication date: 1972-09-05
Anticipated expiration: 1989-09-05

Abstract

A tube is coaxially mounted on one end of a pressure cylinder so that a ram mounted in said cylinder extends and retracts axially of the tube, and a centrally apertured support member is releasably mounted on the free end of the tube in coaxial relation with the ram. One end of a bar is releasably connected to the free end of the ram, a portion of this bar being slidably engaged in the aperture in the support member and in an apertured part one side of which is placed against the end surface of the support member while a bushing is being installed in the part. The free end of the bar projects from the other side of the part and is slidably disposed in the bushing, one edge of which is initially engaged with an edge of the aperture in the part. A pull plate is engaged with the free end of the bar so that retraction of the ram into its cylinder causes the pull plate to draw the bushing into the aperture in the part.

Description

[ Sept. 5, 1972 APPARATUS FOR INSTALLING BUSH-KINGS [72] Inventor: Robert H. Shiflet, Chula Vista,

Calif.

[73] Assignee: Rohr Corporation, Chula Vista,

Calif.

[22] Filed: March 16,1970

[21] Appl.No.: 19,672

[52] US. Cl ..29/263,29/266 [51] Int. Cl. ..B23p19/04 [58] Field of Search ..29/252, 263, 266, 265, 272, 29/234 [56] References Cited UNITED STATES PATENTS 2,253,845 8/1941 Chickner ..29/263 2,068,021 1/1937 Hamman ..29/263 3,469,298 9/1969 Pizzagalli ..29/252X 3,327,377 6/1967 German ..29/263 1,608,407 11/1926 Macias ..29/263 Primary Examiner-Andrew R. J uhasz Assistant Examiner-Leon Gilden Attorney-George E. Pearson [57] ABSTRACT A tube is coaxially mounted on one end of a pressure cylinder so that a ram mounted in said cylinder extends and retracts axially of the tube, and a centrally apertured support member is releasably mounted on the free end of the tube in coaxial relation with the ram. One end of a bar is releasably connected to the free end of the ram, a portion of this bar being slidably engaged in the aperture in the support member and in an apertured part one side of which is placed against the end surface of the support member while a bushing is being installed in the part. The free end of the bar projects from the other side of the part and is slidably disposed in the bushing, one edge of which is initially engaged with an edge of the aperture in the part. A pull plate is engaged with the free end of the bar so that retraction of the ram into its cylinder causes the pull plate to draw the bushing into the aperture in the part.

P'A'TENTEDsEF 5:912

SHEET 1 0F 2 FIG.1

FIG. 2

INVENTOR. ROBERT H. SHIFLET BY EM Q Q ATTORNEY l" 48- V |-L 6 H4: l6 I I I I I FIG. 3

1" I i J ,.I'

4 INVENTOR.

ROBERT H. SHIFLET ATTORNEY APPARATUS FOR INSTALLING BUSHINGS SUMMARY OF THE INVENTION This invention relates to manufacturing apparatus and, more particularly, to apparatus for installing bushings in various parts under a press fit.

In the manufacture of aircraft components and other products, it is necessary to seat cylindrical bushings in apertures in parts of different types with great precision, since even small misalignments of such bushings can make expensive machined parts unacceptable for their intended use. The apparatus disclosed herein provides an effective means for installing bushings in precisely coaxial relation in apertures, and in addition apparatus in accordance with the invention is relatively inexpensive, easy to use, and light in weight so that it can readily be moved to different locations where parts must be assembled. Another advantage of the apparatus is that its design permits certain components thereof to be conveniently varied in size so that different bushings can be installed therewith.

In the preferred form of the invention the inner wall of a tube is threaded so that said tube can be engaged with one end of a hydraulic cylinder, a cylindrical ram projecting from the same end of said cylinder in coaxial relation with the tube. Annular support members formed with apertures of different diameters can be mounted on the free end of the tube in coaxial relation with it and the ram, and draw bars having different diameters can be respectively connected to the free end of the ram so that they extend through, and slidably engage the walls of, the support members used therewith. Each draw bar is adapted to slidably fit in an aperture of particular size in a part, one side of the part being placed against the support member when the described apparatus is in use and the length of each draw bar being such that it projects from the aperture in said part. At its free end each draw bar has a diameter slightly smaller than the inside diameter of a bushing that is to be installed in the aperture of a part, and the free end of each draw bar also projects from said bushing when one edge of the latter is engaged with the edge of the part aperture which is remote from the support member. Extending around the portion of the draw bar which projects from the bushing in a groove. Parallel arms which project from one end of an elongate pull plate are engaged in this groove on opposite sides of the draw bar, and thereafter the ram on which said draw bar is mounted is retracted into the associated cylinder to thereby cause the pull plate to draw the bushing into the aperture in the part abutting the support plate. The arms of the pull plate are then disengaged from the groove in the draw bar so that the latter can be withdrawn from the bushing.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of components of a preferred embodiment of the invention, a pressure cylinder and pull plate of said embodiment being illustrated in fragmentary form and the drawing also illustrating a part and a bushing to be installed in an aperture in said part, a portion of said part being shown in section.

FIG. 2 is another fragmentary side elevation of the same embodiment, illustrating the configuration of the apparatus when the bushing is ready to be pulled into the aperture in the part.

FIG. 3 is a fragmentary side elevation which illustrates the configuration of the apparatus after the bushing has been seated.

FIG. 4 is a fragmentary detail view of a component of the embodiment.

DETAILED DESCRIPTION In FIGS. 1 and 2 reference number 10 designates generally a tubular housing at one end a reduced diameter portion 12 which is provided with a thread 14. In the same drawings reference number 15 designates generally a tube having a slot 18 in the wall thereof and the inner surface of which is threaded at one end to receive the threaded end of housing 10, the tube thus being coaxial with the housing. A hole extends through the end wall of portion 12 of the housing, and a cylindrical ram 20 is slidably mounted in this hole in coaxial relation with said housing and tube 16. The inner end of the ram is connected to a piston (not shown) which is slidably engaged with the inner surface of the large diameter portion of housing 10, and conventional means are provided to pressurize the interior of said housing at any selected time and thereby move ram 20 axially of tube 16.

The inner wall of tube 16 is formed with a counterbore 22 at the free end of the tube, and with a threaded hole 24 which extends from said counter bore to the outer surface of the tube. Reference number 26 designates generally an annular support member comprising (l) a first portion 28 which fits snugly in the counterbored portion 22 of the aperture of tube 16, and (2) a second portion 30 which projects laterally from said first portion and abuts the adjacent end surface 32 of said tube. If desired, a chamfer 34 may be formed on a portion of the edge of support member 26 so that the flat end surface 36 of the support member can be abutted against a part formed with a shoulder which would otherwise contact said edge. A set screw 38 is engaged in hole 24 of tube 16 and may be tightened against portion 28 of support member 26 to lock the same in the counterbore 22 of said tube. The aperture 40 in the support member is coaxial with tube 16 and ram 20.

The free end of the ram is formed with a threaded portion 42 which can be engaged within a threaded hole 44 coaxially formed in one end of a draw bar which is designated generally by reference number 46. This draw bar comprises (1) a first portion 48 which is slidably disposed in the aperture 40 in support member 26 when ram 20 is extended from housing 10 as illustrated in FIG. 2, and (2) a second coaxial portion 50 the diameter of which is less than the diameter of said first portion 48. Extending around the second portion 50 of the draw bar adjacent its free end is a groove 52 (which is referred to in an appended claim as a section of the projecting portion of the draw bar which has a reduced diameter). In the drawings reference number 54 designates generally a pull plate one end of which is formed with a slot 56 which extends longitudinally of said pull plate and thus defines on the latter a pair of spaced,

parallel arms

58, 60. The distance d between the arms of the pull plate (see FIG. 4) is slightly greater than the diameter of draw bar 46 at the bottom of groove 52, so that this reduced diameter portion of the draw bar can be received in slot 56 of the pull plate. The width of groove 52 is such that pull plate is maintained in perpendicular relation with the longitudinal axis of draw bar 46 when it is engaged in said groove.

OPERATION The manner in which the aforedescribed apparatus is used will be explained with reference to a part which is designated generally in FIGS. l3 by reference number 62 and which at one end thereof comprises a pair of

parallel arms

64, 66 respectively having

coaxial apertures

68, 70 therein. To prepare part 62 for its intended use a bushing must be installed in each

aperture

68, 70 therein, one of these bushings being illustrated in FIGS. 1-3, designated generally therein by reference number 72, and comprising (1 a tubular portion 74 which must be forced into one of said

apertures

78, 80 under a press fit and (2) a flange 76 which projects laterally from said portion 74 at one end thereof and which when the bushing is seated abuts the

flat surface

78, 80 which is disposed perpendicular to said one aperture.

A bushing 72 is first inserted between

arms

64 and 66 of part 62 as illustrated in FIG. 1, and then the outer edge of its small diameter end is engaged, for example, with the edge of the aperture 70 of arm 66 as illustrated in FIG. 2. Next the outer side of arm 66 is placed against the end surface 36 of support member 26 as illustrated in FIG. 2 and ram 20 is extended from housing to (l) engage portion 48 of draw bar 46 in the aperture 40 of said support member and in the aperture 70 of said arm 66, and (2) engage portion 50 of said draw bar in the aperture in bushing 72, said portion 50 projecting from the end of said bushing which is remote from arm 66. Pull plate 54 is then engaged with the groove 52 in the projecting end of the draw bar, and thereafter pressure is applied within housing 10 to retract ram therein, which brings the pull plate into abutment with the bushing and draws it into the aperture 70 in arm 66. Preferably the means for pressurizing housing 10 is adapted to exert a selected force against the bushing which is relived as soon as the bushing has been seated in the aperture. Lastly, pull plate 54 is disengaged from draw bar 46 to permit its removal from the bushing.

It will be recognized that support members 26 formed with apertures of different size can readily be attached to the free end of tube 16, and that draw bars 46 adapted for sliding engagement in the apertures of such support members and in the apertures in parts and bushings of different size can also readily be connected to the free end of ram 20. Hence the disclosed apparatus can conveniently be used to install bushings of different size in different parts. It will also be recognized that the arrangement of the apparatus ensures that a bushing is centered in precise coaxial relation with an aperture in which it is installed, and that force is applied to the bushing in an axial direction. Furthermore, apparatus in accordance with the invention is relatively inexpensive to manufacture, easy to use, and is much lighter in weight and more versatile than the arbor presses which are generally employed in the installation of bushings in part.

Various modifications in the construction and arrangement of the described embodiment of the invention can obviously be made without departing from the broad concept of its operation. For example, groove 52 in draw bar 46 m y be replaced with slots formed on opposite sides of e draw bar and adapted to receive the

arms

58 and 60 of pull plate 54. The scope of the invention should therefore be considered to be limited only by the terms of the appended claims.

What is claimed as new and useful and desired to be secured by U.S. Letters Patent is:

1. Apparatus for installing a bushing in an aperture extending through a part, comprising:

a closed tubular housing and a ram mounted in said housing and a portion of which is extensible and retractable relative to a first end thereof by pressure applied therein;

means for pressurizing said housing to thereby selectively extend and retract said ram as aforesaid;

a tube coupled at one end thereof to said first end of said housing and projecting therefrom, said portion of said ram being coaxial therewith, one side of said part abutting said support member during the installation of said bushing in said part aperture, the outer edge of one end of said bushing initially engaging the edge of said part aperture which is remote from said support member;

a draw bar releasably connected at one end thereof to the free end of said ram for aligning said bushing precisely said aperture coaxially therewith and formed with (l a first portion slidably engaged interfittingly within the apertures in said support member and said part, and (2) a second portion part of which is slidably engaged interfittingly within the aperture in said bushing and the remainder of which projects from the side of said bushing remote from said part; and

a flat pull plate releasably engaged with the portion of said draw bar which projects from said bushing, one side of said pull plate being perpendicular to the longitudinal axis of said ram is retracted relative to the first end of said housing, whereby said bushing is drawn into the aperture in said part.

2. Apparatus as defined in claim 1 wherein said support member comprises (1) a first portion which fits snugly in the aperture in said tube and (2) a second portion which projects laterally from said first portion and abuts the adjacent end surface of said tube.

3. Apparatus as defined in claim 1 wherein a section of the portion of said draw bar which projects from said bushing has a reduced diameter and one end of said pull plate is slotted to slidably receive said reduced diameter section of said draw bar.

4. Apparatus as defined in claim 1 wherein said draw bar is threadedly engaged with said ram.

Claims

1. Apparatus for installing a bushing in an aperture extending through a part, comprising: a closed tubular housing and a ram mounted in said housing and a portion of which is extEnsible and retractable relative to a first end thereof by pressure applied therein; means for pressurizing said housing to thereby selectively extend and retract said ram as aforesaid; a tube coupled at one end thereof to said first end of said housing and projecting therefrom, said portion of said ram being coaxial therewith, one side of said part abutting said support member during the installation of said bushing in said part aperture, the outer edge of one end of said bushing initially engaging the edge of said part aperture which is remote from said support member; a draw bar releasably connected at one end thereof to the free end of said ram for aligning said bushing precisely said aperture coaxially therewith and formed with (1) a first portion slidably engaged interfittingly within the apertures in said support member and said part, and (2) a second portion part of which is slidably engaged interfittingly within the aperture in said bushing and the remainder of which projects from the side of said bushing remote from said part; and a flat pull plate releasably engaged with the portion of said draw bar which projects from said bushing, one side of said pull plate being perpendicular to the longitudinal axis of said ram is retracted relative to the first end of said housing, whereby said bushing is drawn into the aperture in said part.