DE8305413U1 - Pneumatic contact member - Google Patents

Description

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Fine metal
society with limited

liability
7033 Herrenherg

Pneumatic contact member

The invention relates to a pneumatic contact member according to the preamble of claim 1.

2Q test adapter for which the pneumatic Contacting member is intended to be used for testing electrical circuit boards, such as those used for electrical and electronic devices, e.g. B. for data processing devices, etc. are common. Such test adapters have an adapter plate, which has a plurality of mutually parallel and perpendicularly penetrating them Has bores which are arranged at a very small distance next to each other and in the spring contact pins can be used. In particular for

₃ Q Testing of assembled printed circuit boards, in addition to the spring contact pins, usually only a small number of pneumatic contacting elements are screwed into additional threaded holes in the test adapter plate, the type that has been customary up to now

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shown in Fig. 1 and described below.

Pneumatic contact members have compressed air connections and are usually only then through the supply of compressed air activated when the normal spring contact

J ^ q cause the test adapter in question to fail have signaled the circuit board concerned. The pneumatic contact members then serve Locating the fault location of the circuit board and they are therefore independent of the compressed air Spring contact pins to get your Contact tips can be operated with the circuit board being tested.

In the known pneumatic 2Q contacting element 1O _x serving this purpose, as shown in FIG. 1, the replacement of its spring contact pin 22 is difficult and cumbersome, since its two-part cylinder 12 must be dismantled for this purpose. Its two cylinder parts 13 and 14 are screwed into a threaded hole 16 of the respective adapter plate 15 from opposite sides. The rear cylinder part 13 is significantly longer than the front cylinder part 14. This longer cylinder part 13 has at its rear end the QQ mouthpiece 17 for connecting the compressed air hose, not shown. A cylinder jacket 18 is attached to this mouthpiece 17, the front end of which has an external thread with which it is screwed into the threaded bore 16 of the adapter plate 15

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is. The front cylinder part 14 is short and also has an external thread with which it g of the screwed into the threaded hole 16 on the other side is. In the rear cylinder part 13, a piston 19 is slidably mounted on his from the working chamber 20 of the cylinder 12 side facing away from a blind hole 21 into which a commercially available Spring contact pin 22 is positively inserted, which is attached to an inner collar the return spring 23 supporting the front cylinder part 14 is constantly pressed against the piston 19 is and is held in its position relative to the piston 19.

The spring contact pin 22 has a sleeve 24 in which a very thin , by a return spring

Spring-loaded contact pin piston 25 can slide axially is used, in which a contact needle 26 is firmly inserted coaxially to it. when the piston of the contacting member 10 by applying compressed air to the working space 20 from the one shown in FIG. 1, is moved to the left in the fully retracted position, the needle 26 moves through the end face Bore 29 of the cylinder 12 through to it on the respective circuit board to be tested hits. The piston 19 can, however, the sleeve 24

₃ q move a little further to the left and thereby the needle 26 can be loaded even more by the pretensioned spring 23. When the working chamber 20 is then again pneumatically relaxed, the piston 19 and the sleeve 24 as well as the

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Piston 25 under the influence of return springs 23, 30 back into the positions shown return.

The assembly of this known contacting device 10 takes place on the adapter plate 15 by first the rear cylinder part 13 is screwed into it and then the spring contact pin 22 and the return spring 23 are used and then the front cylinder part 14 is in the adapter plate screwed in. With the very limited space on the adapter plates due to the high Occupation densities with spring contact pins and pneumatic contacting elements is what Each replacement of the spring contact pin 22 required disassembly of the cylinder 12 difficult and time consuming. In fact, it is often necessary to replace the spring contact pin 22, be it it because of damage to the needle 26 or because having a needle. differently shaped tip required is.

It is therefore the object of the invention to provide a pneumatic contact member of the type mentioned to shafts, in which it is achieved in a structurally simple manner that its contact pin also then when the contacting element is inserted into an adapter plate that has a high occupancy density with spring contact pins and contact members is occupied without Difficulties can be exchanged quickly and easily, even by inexperienced people.

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c. This object is achieved, based on a pneumatic contact member according to the preamble of claim 1, according to the invention by the features specified in the characterizing part of claim 1. _{

, Q This pneumatic contact member according to the invention |

is characterized by the structurally extremely simple %

realized possibility especially light and |

quick replacement of the contact pin even with |

very tight spaces. To replace;

depending on the contact pin it is only necessary *

only in the form of a plug connection in socket I.

to pull out the contact pin held by static friction from the socket from the outside and for him insert a new contact pin into this socket. This is done on the adapter plate in seconds even with a high population density of the

Adapter plate with other such Kontaktierglie- ^

with or with spring contact pins.

2Q The contact pin can be used as with the known pneumatic Contacting member according to FIG. 1 also expediently also a commercially available one in the invention Be spring contact pin. However, it is also possible to use this contact pin as an inherently rigid con-

OQ to train tact pin , whereby its design is simplified.

The cylinder of the pneumatic contacting member can preferably be undivided, which means that it is assembled in

gc of the adapter plate simplified and also replacement |,

or removing the contacting member as a whole _;

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possible, without the cylinder having to be disassembled for this purpose. The easy interchangeability of the contacting pen is retained when the cylinder is made in a known manner from two parts to be inserted separately into the adapter plate is composed. However, it is much more favorable to design the cylinder in one piece.

In Fig. 2 of the drawing, an embodiment of the invention is shown. It shows in longitudinal section Representation of a pneumatic contacting member 40 according to an embodiment of the invention, which is screwed into an adapter plate 15 shown in detail.

This electrically conductive contacting member 40, which consists only of metal parts, has an undivided one Cylinder 41, a piston 42 arranged in the cylinder 41, a piston 42 which is constantly loading, biased return spring 43, a slender bushing 44 firmly connected to the piston 42 and a The contact pin is exchangeably inserted into the socket 44 and held in it only by an adhesive fit 22 'on.

The thin cylinder 41 is composed of three inextricably connected parts, namely one Mouthpiece serving to connect the pressure hose and coaxially penetrated by a compressed air duct 45, a sleeve 46 connected to the mouthpiece 45 by beads, and a sleeve 46 inserted into the sleeve 46

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and forehead connected to it by beads piece 47 on. The end piece 47 has an external thread 48, with which it is in an internal thread of a Screwed through hole of the adapter plate 15 is. The remaining wall of the cylinder 41 is smooth.

jQ The one in its most retracted position The piston 42 shown has an annular seal 49 in this exemplary embodiment. However, it is without further ado also possible and particularly advantageous / to refrain from such a ring seal by the Fit of the piston 42 in the cylinder 41 is provided so closely with slide bearing play that the piston circumferential wall causes sufficient compressed air sealing by itself. The rear face 50 of the piston forms the movable wall surface of the working space 51 of the cylinder 41. In the other The end face of the piston 42 has an axial blind hole 52 in the center, into which the very thin, smooth, circular cylindrical metal tube formed socket 44 inserted positively and is firmly and permanently connected to the piston 42 by a laser weld 53. This socket 44 is coaxial with the piston 42 and the cylinder 41 and its left front face is in the illustrated, fully retracted position of the piston 42 flush with the front face of the cylinder 41.

The return spring 43 loading the piston 42 is supported on the rear face of the End piece 47 of the cylinder 41 from.

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In the socket 44, the contact pin 22 'is inserted / which has a smooth cylindrical shaft or sleeve 55 / over the or die-coaxially a · reduced in diameter cylindrical needle 56 protrudes, which has a sharp point 57. This contact pin 22 'can a one-piece, rigid contact pin or a spring contact pin similar to the spring contact pin 22 according to FIG. 1.

The sleeve 55 of this spring contact pin 22 ', whose Needle 56 then like needle 26 (Fig. 1) with-

is resiliently guided by means of a piston and a return spring in the sleeve 55, or the shaft 55 this contact pin 22 'are smooth on the circumference and with a tight fit in the socket 44 until they are seated on the bottom of the blind hole 52 of the piston 42

exchangeable by hand. To replace one only has to remove the contact pin 55 from the Pull out socket 44 and insert the new contact pin into this socket 44 in its place.

The cylinder 41, the piston 42 and the socket 44 of the contacting member 40 are rotationally symmetrical.

There is also a 30 on the cylinder 41 near the mouthpiece 45

electrical conductor 56 'for electrical connection this contact member 40 is welded onto which an insulating tube 57 for electrical insulation is postponed.

Since the bush 44 with the piston 42 against the

Action of the return spring 43 with moved to the left,

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when to activate this contact member 10 of the
& Working space 51 with compressed air through a to the
Mouthpiece 45 to be connected, not shown
Compressed air hose is pressurized through with compressed air, this socket 44 is in the central,
cylindrical bore 58 of the end piece 47 of the i

Cylinder 41 with slide bearing play can be moved axially S

stored. The compressed air can therefore the piston 42 ^ö

with socket 44 and contact pin 22 'to the left |

because of until the required electrical contact |

the needle 56 of the contact pin 22 'with a \

Printed circuit board is made and the electrical
Contact goes to the contacting element kO
Head 56 ¹ and from it on to an evaluation device, not shown. When the work space
51 is relieved of pressure, the spring 43 pushes the

Piston 42 with socket 44 and contact pin 22 «how ^!

which returns to the rest position shown. i:

The design of spring contact pins results from

the spring contact pin 22 of Fig. 1. The Federkon- t

The contact pin 22 'can be a commercially available spring contact pin, such as those manufactured in large numbers 1 by the applicant in, among others. Therefore, jj does not need any further | for a person skilled in the art Explanation of the spring contact pin 22 ', f_

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It is also possible to use the cylinder 41 in other ways than;

to be fixed by screwing into the adapter plate 15, ΐ

for example by pressing in with an interference fit, by pressing;

glue or the like. He then does not need an external thread. _;

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It is of course, also possible, if desired, to form the contact member 40 so that the needle 56 of the contact pin 22 'in the full retracted position of the sleeve 44 in the cylinder 41 is partially or completely sunk. For this purpose, for example, the contacting member 40 according to FIG. 2 can be changed so that its Socket 44 in the retracted position within the cylinder 41 at a distance from its end face 54 ends so that the contacting member 22 ″ can be designed so that its needle 56 then in the fully retracted position the socket 44 is partially or completely within of the cylinder 41 is located. Or you can use the contacting member 40 shown in Fig. 2 so far to the right in the adapter plate 15 offset so that the needle 56 in the retracted

2Q position of the socket 44 is completely or partially in the relevant hole in the adapter plate 15 is located.

Claims (7)

e. r-- »55Ο3-1 - claims for protection 1. Pneumatic contacting element for testing electrical circuit boards, preferably from assembled circuit boards, test adapters, with one in an adapter plate of the test adapter to be fastened thin cylinder, in which a spring-loaded by a return spring Piston is axially slidably guided, with which a contact pin is axially movably connected is, the one facing away from the contact pin The front side of the piston is the movable wall surface of the working space that can be pressurized with pressurized gas [of the cylinder is characterized by ι draws that at the from the work area (51) facing away from the inr cylinder (41) Piston (42) has a slim socket (44) for the replaceable plugged into it Contact pin (22 ') is arranged. 2. Pneumatic contacting member according to claim 1, characterized in that the cylinder (41) is undivided. 3. Pneumatic contacting member according to claim 1 or 2, characterized in that the contact pin (22 ') is a commercially available spring contact pin is. 4. Pneumatic contacting member according to claim 1 or 2, characterized in that the contact 5503 - 2 - I pin (22S is inherently rigid. 3 5 5. Pneumatic contact member according to one of the preceding claims / marked thereby! net that in the most retracted T position of the piston (42) the bushing (44) itself i takes place completely inside the cylinder (41) bell J ^ q and through the piston out of the cylinder r is extendable. I. 6. Pneumatic contact member according to one of the t preceding claims _T characterized I ₁₅ that the bushing (44) with the piston (42) through a laser welding stub (53) is firmly connected. § 7. Pneumatic contacting member according to one of the The preceding claims, characterized in ^{that the bush is} axially slide-mounted in the cylinder. 25th 30th ! 35