US3111750A

US3111750A - Standoff tool

Info

Publication number: US3111750A
Application number: US87151A
Authority: US
Inventors: Donovan J Moore; Walter W Skifstrom
Original assignee: SPACE TECHNOLOGY LAB Inc
Current assignee: SPACE TECHNOLOGY LAB Inc; SPACE TECHNOLOGY LABORATORIES Inc
Priority date: 1961-02-06
Filing date: 1961-02-06
Publication date: 1963-11-26
Anticipated expiration: 1980-11-26

Description

Nov. 26, 1963 D. J. MOORE ETAL STANDOFF TOOL Filed Feb. 6, 1961 FIGZ.

.sial i.

I Hi 4 0 3 I 4 I P WALTER W. SKIFSTROM DONOVAN J. MOORE ATTORNEY.

FIG.6.

United States Patent M 3,111,750 STANDOFF TOQL Donovan J. Moore, Los Angeles, and Walter W. Skifstrom, Gardens, Calif assignors to Space Technology Laboratories, Inc., Los Angeles, Calif, a corporation of Delaware Filed Feb. 6, 1961, Ser. No. 87,151 3 Claims. (Cl. 29235) This invention relates to a standoff tool for inserting friction fit terminals into previously assembled bulkhead partitions of electronic chassis.

Terminals of the so-called friction fit variety have become widely used in the electronic packaging industry due to their high electrical performance and their high reliability in maintaining positional alignment. The friction fit terminal consists of a circular insulating bushing member, usually constructed of a polyester such as Teflon, and an electrical conducting member centrally located within said bushing member. The electrical conductor may be of any shape or size depending on the needs of the particular installation. The terminal is inserted into an opening having a diameter that is less than the diameter of the insulating member, thereby requiring a slight flowing and deformation of the bushing member. This type of fit is known as an interference fit. One of the more successful of these friction fit terminals is the Press- Fit terminal manufactured by the Sealectro Corporation, which uses a Teflon bushing. The Tefion bushing of the Press-Fit terminal is formed with a shoulder at one end to provide a bearing surface for limiting the travel of the terminal.

The terminals are normally installed in the chassis by means of machine tools usually arranged to hold the conductive portion of the terminal and provide an axial force until the Teflon bushing has been inserted and held in place by the shoulder portion. This type of installation is preferred, since it is desired that a force coaxial with the terminal be maintained until the bushing is properly sealed.

In the design and construction of highly sophisticated electronic equipment, it is usually required that each stage and subchassis be electromagnetically sealed from each other. This has necessitated the construction of chassis members that are compartmentalized by means of a plurality iof bulkhead members. In order to provide the high degree of shielding necessary, these bulkhead members are usually soldered to the basic member and then completely plated with an electrical conductor having a high conductivity such as gold or other similar material. The placement of a terminal in a bulkhead member of the type just described becomes almost an impossibility due to the defined interference fit and the inability of an operator to maintain a force coaxial with the terminal.

This invention is concerned with a hand tool that holds the terminal and supplies the necessary force and in the proper direction so as to properly and easily insert the oversized Teflon bushing into the mating hole. The tool is adapted to be hand operated and is arranged to hold different sized terminals for insertion into bulkhead members that are presently inaccessible by present day techniques.

Further objects and advantages of the present invention will be described as the description progresses, reference now being made to the accompanying drawings wherein:

FIG. 1 illustrates a preferred embodiment of the tool in the process of inserting a terminal member;

FIG. 2 is a partial view of the tool illustrating a second embodiment for holding a plurality of terminal members;

FIG. 3 is a section taken along line 3-3 of FIG. 1

3 ,lll,750 Patented Nov. 26, 1963 illustrating the holding member and anvil member of the tool in greater detail;

FIG. 4 is a partial section taken along line 6-3 of FIG. 1 illustrating a first step in inserting a terminal member;

FIG. 5 is a partial section taken along line 3-3 of FIG. 1 illustrating a second step in inserting a terminal member;

FIG. 6 is an exploded view of the split chuck member forming part of the tool illustrated in FIG. 1; and

FIG. 7 is a pictorial view of a chassis member having a plurality of bulkhead members and a number of terminal members inserted therein, in accordance with the present invention.

Referring now to FIG. 1, there is shown a chassis member 10 having a plurality of bulkhead members 11 and 12 each arranged with a plurality of holes 13 adapted to receive a terminal 14. The terminal 14 is of the type commonly known as a feedthrough terminal and consists of a conductive member 15 and an insulating bushing 16. As the description progresses it will be realized that other types of terminals, such as standoifs, feedthrough, and connectors, may be used. The aforementioned terminals differ only in the shape of the conductive member 15. The size of the various terminals will usually be determined by their current carrying capacity and as such will be reflected in a larger sized conductive member 15 and a larger sized insulating bushing 16. The relationship, however, between the diameter of the hole 13 and the diameter of the insulating bushing 16 is always the same in that the diameter of the bushing 16 is approximately 0.003 to 0.005 larger than the diameter of the hole, thereby insuring an interference fit. The terminal 16 is supported by means of an adjustable split chuck l7 rotatably supported at one end of a tool 13. Opposing the split chuck '17 is a rotatably mounted anvil 19 having an opening which has a diameter that is at least larger than the largest insulating bushing used. The tool 18 consists of a pair of hand operated lever arms 2i) and 21 pivoted together and arranged to cause a relative movement between the split chuck 17 and the anvil 19. The particular embodiment illustrated causes a direct force between the split chuck '17 and the anvil 19 that is coaxial with the terminal 14 held by the split chuck. The split chuck 17 is supported at one end of a support arm 22, which arm is pivotally connected to lever arm 21 and slidably attached to lever arm Zll. In a similar manner, the anvil 19 is located at one end of a support arm 23 opposite the split chuck 17. The arm '23 is pivotally connected to lever arm '20 and slidably attached to lever arm 21. The defined pivotal connections on

support arms

22 and 23 define a parallelogram which establishes a parallel motion between

arms

22 and 23, upon lever arms and 21 being moved.

Referring now to FIG. 2, there is illustrated a six sided split chuck 24 having the ability to support at least six different sized terminal members 14.

Referring now to FIG. 3, there is shown a section taken along lines 33 of FIG. 1 illustrating in more detail the construction of the split chuck 17 and the anvil 19. The support arm 22 illustrated in FIG. 1 is preferably constructed of a pair of

similar arms

25 and 26. Located between said

arms

25 and 26 is the split chuck 17. The split chuck 17 may have any number of faces, such as the four faces illustrated in FIG. 1 or the six faces illustrated in FIG. 2. Each face has a different sized hole drilled radially for accepting the conductive member 15 of the terminal 14. Greater adaptability and support of the terminal members are achieved by constructing the split chuck 17 from a pair of matching

face members

27 and 28 which are held

intermediate arms

25 and 26. The complete assembly includes a friction spring 29 and is held together by means of a suitable rivet 30. In actual practice the split chuck 17 is rotatable in order to allow selection of the particular face having the desired opening for holding a given sized terminal. The friction spring 29 provides the necessary force for holding the

split face

27 and 28 members together. The anvil 19 is located Within a pair of

similar arms

31 and 32 which comprise member 23 in a similar manner that arms 25' and 26 define arm 22. The anvil 19 is required only to contain an opening 33 having a greater diameter than the diameter of the largest insulating insert used. The complete anvil assembly is joined to

arms

31 and 32 by means of a rivet 35 thereby making the anvil assembly rotatable and adaptable to the needs of the tool 18.

FIGS. 4 and 5 illustrate the steps necessary to insert the termn-ial 14 into the opening 13. One end of the conductive member 15 is inserted into the split chuck 17 located at one end of the tool 18. This serves to support terminal member 14 in any position as required by the geometry of the bulkhead member 12. In operation, the anvil 19 is pressed against one side of the bulkhead member 12 and the bushing 16 is placed against the opening 13 in the bulkhead opening 12. Since .the opening 13 has a smaller diameter than the diameter of the bushing 16, it is necessary that a continuous and direct pressure he applied on the

lever members

20 and 21 so to axially drive the split chuck member 17 against the anvil member. A shoulder 36 is formed on the bushing 16 and acts as a limiting stop on the insertion of the terminal member 14 into the bulkhead 12. The deformation of the bushing 16 provides the necessary elastic force to rigidly set the terminal member in place. Simply reversing the direction on the lever members 20 and 2.1 will cause the chuck member 17 to slip on the conductive member 15 thereby allowing the chuck member to be pulled free of the terminal.

Referring now to FIG. 6, there is shown an exploded view illustrating the split chuck composed of face members 27' and 28 that are held in mating relationship by means of

arms

25 and 26 and friction spring 29. The different

sized grooves

37 and 38 for accepting different sized terminal diameters are more fully illustrated and realized.

Referring now to FIG. 7, there is shown a pictorial representation of a typical compartmentalized chassis formed by the bulkhead members 12. This figure illustrates how ineffectual pliers or other similar tools would be for inserting terminal members 14 into an interference fit located in the bulkhead defined by the bushings 16 and the holes 13. It will be appreciated also that with the great need for high density packaging and the larger depth chassis used, that the problem of inserting a terminal in the bottornmost portion of the bulkhead members is practically impossible without the tool described in the present invention.

This completes the embodiment of the invention illustrated herein; however, many modifications and advantages thereof will be apparent to persons skilled in the art without departing from the spirit and scope of this invention. Accordingly, it is desired that this invention not be limited to the particular details of the embodiment disclosed herein except as defined by the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A tool for inserting a terminal device, having a conductive member located centrally in an insulating bushing into an opening in a bulkhead member defining an interference lit with said bushing comprising a pair of actuating levers adapted to be hand operated, a chuck assembly rotatably mounted at one end of one of said levers, said chuck assembly comprising split portions adapted to receive the terminal portion of said device therebetween and a spring mounted adjacent the split portions to bias said split portions into gripping engagement with said terminal portion, said split portions having a substantially polygonal form defining a plurality of faces, each face having a diiferent diameter aperture extending perpendicular to the face for accepting and holding different sized terminal devices, and an anvil member rotatably mounted at one end of said other lever and adapted to provide a reference for applying a force on said conductive member coaxial with said bushing, said anvil member having an opening that is larger than the diameter of the bushing being inserted, said anvil member and said chuck assembly being disposed on similar portions of said levers whereby movement of said levers causes relative movement between said opposing anvil member and said chuck assembly.

2. A tool for inserting a terminal device, having a conductive member located centrally in an insulating bushing, into an opening in a bulkhead member defining an interference fit with said bushing comprising :a chuck assembly movably mounted at one end of a first supporting member, said chuck assembly comprising split portions adapted to receive the terminal portion of said device therebetween and a spring mounted adjacent the split poitions to bias said split portions into gripping engagement with said terminal portion, an anvil member movably mounted at one end of a second supporting member and adapted to provide a reference for applying a force on said conductive member coaxial with said bushing, and a pair of actuating levers pivotally connected to said first and sec ond members for causing relative parallel movement be tween said members upon movement of said levers, said anvil member and said chuck assembly being disposed on a similar but opposing portion of said first and second member respectively.

3. A tool for inserting a terminal device, having a conductive member located centrally in an insulating bushing, into an opening in a bulkhead member defining an interference fit with said bushing comprising a chuck assembly pivotally mounted at one end of a first supporting member, said chuck assembly comprising split portions adapted to receive the terminal portion of said device therebetween and a spring mounted adjacent the split portions to bias said split portions into gripping engagement with said terminal portion, said split portions having a substantially polygonal form defining a plurality of faces, each fiace having a different diameter aperture extending perpendicular .to the face for accepting and holding different sized terminal devices, and an anvil member pivotally mounted at one end of a second supporting member and adapted to provide a reference for applying a force on said conductive member coaxial with said bushing, said anvil member having an opening that is larger than the diameter of the bushing being inserted, and a pair of actuating levers pivotally connected to said first and second members for causing relative parallel movement between said first and second members upon movement of said levers, said anvil member and said chuck assembly being disposed on a similar but opposing portion of said first and second member respectively.

References Cited in the file of this patent UNITED STATES PATENTS

Claims

1. A TOOL FOR INSERTING A TERMINAL DEVICE, HAVING A CONDUCTIVE MEMBER LOCATED CENTRALLY IN AN INSULATING BUSHING INTO AN OPENING IN A BULKHEAD MEMBER DEFINING AN INTERFERENCE FIT WITH SAID BUSHING COMPRISING A PAIR OF ACTUATING LEVERS ADAPTED TO BE HAND OPERATED, A CHUCK ASSEMBLY ROTATABLY MOUNTED AT ONE END OF ONE OF SAID LEVERS, SAID CHUCK ASSEMBLY COMPRISING SPLIT PORTIONS ADAPTED TO RECEIVE THE TERMINAL PORTION OF SAID DEVICE THEREBETWEEN AND A SPRING MOUNTED ADJACENT THE SPLIT PORTIONS TO BIAS SAID SPLIT PORTIONS INTO GRIPPING ENGAGEMENT WITH SAID TERMINAL PORTION, SAID SPLIT PORTIONS HAVING A SUBSTANTIALLY POLYGONAL FORM DEFINING A PLURALITY OF FACES, EACH FACE HAVING A DIFFERENT DIAMETER APERTURE EXTENDING PERPENDICULAR TO THE FACE FOR ACCEPTING AND HOLDING DIFFERENT SIZED TERMINAL DEVICES, AND AN ANVIL MEMBER ROTATABLY MOUNTED AT ONE END OF SAID OTHER LEVER AND ADAPTED TO PROVIDE A REFERENCE FOR APPLYING A FORCE ON SAID CONDUCTIVE MEMBER COAXIAL WITH SAID BUSHING, SAID ANVIL MEMBER HAVING AN OPENING THAT IS LARGER THAN THE DIAMETER OF THE BUSHING BEING INSERTED, SAID ANVIL MEMBER AND SAID CHUCK ASSEMBLY BEING DISPOSED ON SIMILAR PORTIONS OF SAID LEVERS WHEREBY MOVMENT OF SAID LEVERS CAUSES RELATIVE MOVEMENT BETWEEN SAID OPPOSING ANVIL MEMBER AND SAID CHUCK ASSEMBLY.