US3696492A

US3696492A - Tools for plugging in and unplugging subsystems carried on slideways

Info

Publication number: US3696492A
Application number: US122389A
Authority: US
Inventors: Marcel Baillard
Original assignee: Airbus Group SAS
Current assignee: Airbus Group SAS
Priority date: 1970-03-18
Filing date: 1971-03-09
Publication date: 1972-10-10
Anticipated expiration: 1989-10-10
Also published as: DE2104567B2; DE2104567A1; FR2082515A5; DE2104567C3

Abstract

A portable tool permitting, as desired, either selective plugging in of a printed-circuit module into one of a plurality of bottom grooves formed in a rack and above which groove the module is restrained by lateral slideways, or selective unplugging of one of the modules plugged into the bottom rack grooves. It comprises a grip formed by two elements movable relatively to each other. One of these elements is provided with a pair of claws adapted to engage lateral recesses in the rack when the operator moves the two grip elements toward each other. The other element is provided on the one hand, with pushing rods acting on the module to be plugged and, on the other hand, with hooks acting on the module to be unplugged, after having turned the grip the other way round.

Description

United States Patent Baillard 1151 3,696,492 1451 Oct. 10, 1972 [72] Inventor: Marcel Baillard, Seine, France [73] Assignee: Societe Nationale Industrielle Aerospatiale, Paris, France [22] Filed: March 9, 1971 [21] Appl. No.: 122,389

[30] Foreign Application Priority Data March 18, 1970 France ..7009752 52 us. c1. ..29/203 11 511 1111.01. ..B25b 27/02 58 Field of Search...29/203 H, 203 B, 278; 294/15, 294/16, 28

[56] References Cited UNITED STATES PATENTS 3,443,297 5/1969 Lusby ..29/203 H 11/1970 Bruner ..29/203 H 12/1971 Greenspan ..29/203 11 Primary Examiner-Robert C. Riordon Assistant Examiner-J. C. Peters Attorney-Karl W. Flocks [5 7] ABSTRACT A portable tool permitting, as desired, either selective plugging in of a printed-circuit module into one of a plurality of bottom grooves formed in a rack and above which groove the module is restrained by lateral slideways, or selective unplugging of one of the modules plugged into the bottom rack grooves. It comprises a grip formed by two elements movable relatively to each other. One of these elements is provided with a pair of claws adapted to engage lateral recesses in the rack when the operator moves the two grip elements toward each other. The other element is provided on the one hand, with pushing rods acting on the module to be plugged and, on the other hand, with hooks acting on the module to be unplugged, after having turned the grip the other way round.

5 Claims, 9 Drawing Figures PATENTEDnm 10 m2 SHEET 1 0F 7 INVENTOR MARCEL BAILLARD BY Kan L Ffocn H TTOR/VE Y The use of equipment for testing or controlling the electro-mechanical circuits to be found in systems of all kinds employed in the various spheres of modern activity has resulted in the introduction of cabinets of by no means negligible size, equipped with slide-in units or racks containing the equipment designed to perform the required functions.

In order, on the one hand, to reduce the number and size of such individual items and hence the cost of each installation and, on the other, to simplify the equipment handling operations inherent in the performance of each operation, it has been necessary to devise modules corresponding to specific circuits. These modules, which are made of insulating material, carry printed circuits and provide the requisite electronic components, are removably and interchangeably inserted into slideway systems with which the above-mentioned racks are equipped and, by their very association, provide the circuits needed for performing the required operation.

Experience has shown that notwithstanding these slideways the insertion or withdrawal of each such module, into and from the various racks, represents a very delicate manual operation by reason of the very small gaps existing between consecutive modules, which gap must nonetheless permit insertion or withdrawal of each module in addition to accommodating the various components equipping the printed circuits and which bulk to a considerable extent due to the presence of transistors, capacitors, resistors and so forth.

In view of these difficulties and in order to avoid damage to the modules, their circuits and their equipment as the result of inadvertent clumsiness when inserting or withdrawing the modules, the need arose to design and develop a device for plugging in or unpiugging these modules.

During insertion, each module is introduced manually along the side rails provided in the rack. On the other hand, the final operation-of plugging in, i.e., of engaging it into the bottom groove, is much trickier because it involves exerting a considerable force uniformly distributed over the upper edge of the module in order to ensure correct engagement. This delicate operation can be accomplished in outstandingly simple, efficient and reliable fashion by means of the device specifically designed for the purpose and which forms the object of the present invention.

This device is designed to make it possible to perform the reverse operation of selectively withdrawing modules one by one. Previously, this unplugging operation also required the application of a force, this time in the opposite direction, and which, again in order to avoid damaging the equipment, is uniformly distributed over the entire periphery of the module and is directed rigorously along the plane of symmetry of withdrawal of each module.

In other words the present invention relates to a simple, easy to handle device, requiring no special precautions in use, which, by being merely applied against the rack level with the corresponding rails, makes it possible to plug in or unplug the required modules by inserting a uniformly distributed compressive or pulling force directed along the centerplane of said modules. The subject device of this invention avoids damage to the modules as a result of accidental mishandling when inserting or withdrawing them, thereby endowing them with great reliability notwithstanding the numerous manipulations to which they are subjected.

A portable device according to this invention is characterized by the fact that it comprises:

a grip consisting of two elements movable relatively to each other and normally kept spaced from each other by return springs;

two sets of movable arms pivotally mounted at either end of one of the grip elements and capable, in their resting positions, of penetrating into the rack on either side of the-module to be plugged in, which arms comprise claws adapted to engage into recesses provided for the purpose in the lateral walls of the rack;

two actuating systems of the cam type which, when the operator moves the two grip elements toward each other, is effective in initially fetching the movable arms into a position wherein their claws engage into the anchoring recesses, and thereafter in exerting a pressure uniformly distributed over the upper edge of the module whereby to cause the same to engage into the bottom groove;

two extraction hooks fixed to either end of the second grip element and which, after the operator has turned the grip the other way round, enable him to engage them into holes provided for the purpose in the module to be unplugged and to thereafter withdraw the same by moving the two grip elements toward each other, during which operation the grip reacts against the edges of the rack through two abutments fast with the grip element provided with the claw-bearing movable arms.

The description which follows with reference to the accompanying non-limitative exemplary drawings will give a clear understanding of how the invention can be carried into practice. i

In the drawings:

FIG. 1 is a perspective showing of a device according to this invention, portrayed in the position in which it must be grasped in order to plug a module into a rack;

FIG. 2 is an end view of FIG. 1;

FIG. 3 is a side elevation view with partial cutaway;

FIG. 4 is a detail view on an enlarged scale showing the fastening claw actuating mechanism of the device in sectional side elevation;

FIG. 5 is a cross-section along the line V--V of FIG.

FIG. 6 is an explanatory illustration of the manner of operation of the device, as used for plugging a module into a rack;

FIG. 7 is a cross-section taken along the line VII- VII of FIG. 6;

FIG. 8 is an explanatory illustration of the manner of operation of the device, as used for withdrawing a module from a rack; and FIG. 9 is a cross-section taken along the line IX-IX of FIG. 8.

The device shown for exemplary purposes in the drawings may be likened in general shape to a springtype dumb-bell in that it is formed by a two-part grip, namely of two parallel cylinders 1 1,, which can be gripped in one hand and tightened together against countering

springs

2,, 2,,. These springs are carried on two

end posts

3,, 3,, which likewise form guides for the motion of element 1,, relatively to element 1,. The

posts

3,, 3,, accordingly have one of their ends fixed into the corresponding ends of element 1,, as is clearly shown at 4 in FIG. 3, while the other element 1,, is provided with bushes 5 through which the associated posts slide. The latter protrude through element 1,, and their outer ends are fitted with

caps

6,, 6,, the functions of which will be explained in greater detail hereinafter. Adjacent its ends, movable element 1,, is provided with rods 7,, 7,, whose respective axes XX and YY lie in the vertical symmetry plane PP of the device, which plane is shown in a dot-dash line in FIG. 2. The rods 7,, 7,, have tapering

terminal portions

8,, 8,, which are curved to form

extraction hooks

9,, 9,. It is important to note, as is clearly shown in FIGS. 1 and 9, that the tapering

portions

8,, 8,, are curved in such manner as to cause the pulling force exerted by the hooks to lie in symmetry plane PP,.

Adjacent to the ends of element 1,, are fixed the bases of

cylindrical rods

10,, 10,, extending through element 1,, being guided therethrough by bushes such as the bush 11 shown in FIG. 3. The unrestrained ends of

rods

10,, 10,,, which protrude from element 1,, respectively comprise, from top to bottom in FIG. 3, downwardly tapering frusto-

conical portions

12,, 12,,

cylindrical portions

13,, 13,, of smaller diameter than

cylindrical portion

10,, 10,,, and

transverse thrust plates

14,, 14,, to the functions of which further reference will be made when the manner of operation of the device is described. The two ends of element 1, comprise

heads

15,, 15,, of rectangular shape for example and larger in size than the middle cylindrical portion 1,, whereby to accommodate therein the upper portion of the anchoring claw assembly which will now be described with particular reference to FIG. 3 and to the two detail FIGS. 4 and 5.

Each

head

15,, 15,, comprises two

lateral slots

16,, 17, (or 16,,, 17 which extend right through it. Accommodated in these slots and capable of swinging motion are the

upper ends

18,, 19, of

arms

20,, 21, and 20,, 21 fulcrumed on pivots 22 23,. Springs 24 positioned respectively in said slots continuously urge the

pivotal arms

20,, 21,, 21 B toward the protruding portion of the associated

rods

10,, 10,, whereby to cause them to bear against the

respective thrust plates

14,, 14,,. The lower ends of

arms

20,, 21,, 20 21,, are provided with outwardly turned fastening

claws

24,, 25,, 24,, 25,, to which further reference will be made when the manner of operation of the device is described.

Between the

lateral arms

20, and 21, is disposed a transverse camming plate 26 provided with two

arms

27,, 28, engaged into said

slots

16,, 17, and capable of swinging motion therein about the

pivots

22,, 23,. Adjacent its upper central portion, plate 26 is provided with a cylindrical rivet 27 the head of which normally registers in contact with the joint between frusto-conical portion 12, and the smaller-diameter cylindrical portion 13, of guide 10,. Further, fixed to plate 26, beneath rivet 27, is a transverse spring blade 28 the ends of which engage in corresponding recesses 29,, 30, formed in claw-

arms

20,, 21, (see FIGS. 4 and 5). Spring blade 28 is secured by a screw 31 and an appropriately arcuate second spring blade 32.

It will already be manifest that, through the agency of

spring blades

28 and 32, any pivotal motion of plate 26 about its hinge axis will cause the claw-

arms

20,, 21, to pivot in the same direction against the countering return springs 24, and that, if for any reason one of the claw-arms should butt against an obstacle preventing it from pivoting, the three other claw-arms of the device are themselves nevertheless able to pivot.

Particular reference will now be had to FIGS. 4, 5, 6 and 7 for a description of the device in its function of ensuring perfect insertion of a module into a rack.

In FIGS. 6 and 7 a rack generally designated by reference numeral 33 is schematically illustrated in cross-section and longitudinal section respectively.

Along the

side walls

33,, 33,, of rack 33 are provided unifomtly spaced

vertical slideways

34, 34, 34, 34, 34, 34 while in the rack bottom 33,- are formed

transverse grooves

35,,, 35, 35, which interconnect these slideways in pairs.

Further, formed in

side walls

33, and 33,, are two

horizontal grooves

36,, 36,, for receiving the claws of the movable arms of the device and for providing fastening points therefor, as will be explained in greater detail hereinbelow.

Each combination of two vertical slideways and the associated bottom groove can receive a board or module equipped with its printed circuit, such as 37,,, 37, 37,,

Obviously, constant spacing between consecutive modules is so determined that, once the modules are in position, their printed circuits should connect with one another and also so that it be possible for a claw-arm to penetrate therebetween to a sufficient distance for its claw to register with the corresponding fastening groove.

When a new module such as module 37,, is to be inserted, it is first inserted manually into the vertical slideways reserved for the purpose (in this case the

slideway

34, 34,,,). Module 37,, will then be in the position shown in solid lines in FIGS. 6 and 7. At this stage recourse is had to the subject device of this invention for the final delicate operation of plugging in the module, that is to say of inserting it into the bottom groove 35 To that end the device is grasped in one hand and fetched into the position shown in solid lines in FIG. 6. This is accomplished by inserting

movable arms

20,, 20,, and 21,, 21,, between modules 37, 37,, and 37,;,, 37,, respectively, until the lower edges of camming plates 26 bear against the upper edge of the module 37,, to be plugged in, the centerplane of which will then lie in the centerplane PP of the device.

Upper element 1,, is then pressed toward element 1,. During the initial stage of the descent of

rods

10,, 10 it will be seen that frusto-

conical portions

12,, 12,, will coact with the rivet heads 27 to thrust the corresponding plates 26 outwardly. Through the agency of

spring blades

28 and 32, the plates 26 accordingly thrust

arms

20,, 21 and 20,,, 21,, outwardly, thereby causing the

claws

24,, 25, and 24 25,, to engage in the corresponding

horizontal grooves

36,, 36,, which accordingly serve as fastening points. As element 1,, continues to be squeezed toward element 1, against countering

springs

2, and 2

thrust blades

14, and 14,, on

rods

10, and 10,, then exert, against the upper edge of module 37, a symmetrical downward thrust since the device is locked in position by the claws engaged in the horizontal grooves. Responsivelyto his uniformly distributed and vertically centered force, module 37,1 is plugged into the lower groove 35A being uniformly nested therein in parallelism with the centerplane of the module. The various component parts of the device are then in the final configuration shown in dotted lines in FIG. 6.

Once the module has been plugged in, the pressure on element 1 can be released to allow the latter to be raised by the return springs 2 and 2 and the

frustoconical portions

12,, 12,, of

rods

10,, and 10,, to retract. The four claws 24 25 and 24 25 then revert to their initial resting positions and the device can be withdrawn from the rack.

As indicated precedingly, it should be noted that by vi'rtue of the elastic actuation of the claw-arms, it is possible for one of these arms to remain retracted while the others move into their fastening positions if, for instance, that arm were to be hindered in its movement toward the fastening groove by possibly bulky and projecting components like potentiometers, capacitors, resistors, transistors, and the like, carried on certain modules. In that event the claw-arm in question will remain retracted without preventing plugging in from being effected by means of the other three claw-arms.

The device will now be described in connection with its use for withdrawing a module from a rack, with particular reference to FIGS. 8 and 9.

In order to avoid an unnecessarily lengthy description, the description of the arrangement of the modules in rack 33 will not be repeated, and it should merely be noted that in this case all the

modules

33, 33, 33

. are fully inserted into the corresponding bottom grooves 35 35, 35

In order to unplug one of the modules, for example module 37 the device is grasped in one hand, but this time the other way round, that is to say with element 1,, upwards. The two ends 9 and 9,, of extraction hooks 8,, and 8,, are then inserted into extraction holes 38 38 provided for the purpose along the edge of each module.

The two

elements

1 and 1 of the device are then squeezed together, and the initial effect of this is to cause the two caps 6 6 to contact the upper face of the

side walls

33,, and 33,, of the rack, which walls accordingly serve as reaction points for the device. If the two

elements

1 and 1,, continue to be squeezed together, lower element 1 will move toward upper element 1 thereby causing module 37 to be withdrawn from bottom groove 35, and to be fetched into the position shown in dotted lines in FIG. 8. As explained precedingly, by virtue of the curved shape of extraction hooks 8,, 8 module 37, is withdrawn along the centerplane PP, of the device and consequently along the centerplane of the module. After the latter has been extracted from bottom groove 35, it can easily be removed from

lateral slideways

34, 34, and then detached from hook ends 9 and 9 An alternative module corresponding to the new program required can then be plugged in, in the manner described hereinabove with reference to FIGS. 6 and 7.

It goes without saying that many changes and substitutions may be made in the embodiment described for exemplary purposes hereinbefore, without departing from the scope of the invention as set forth in the appended claims.

I claim:

1. A portable device permitting, as desired, either selective plugging in of a printed-circuit module into one of a plurality of bottom grooves formed in a rack and above which groove the module is restrained by lateral slideways, or selective unplugging of one of the modules plugged into the bottom rack grooves, said device comprising: i

a grip formed by two elements movable relatively to each other and normally held in mutually spaced relationship by return springs;

two sets of movable arms pivotally mounted at either end of one of the grip elements;

said movable arms being capable, in their resting position, of penetrating into the rack and being provided with claws capable of engaging into lateral recesses provided for the purpose in the side walls of the rack;

two cam type actuating means so devised that when the operator moves the two grip elements toward each other they initially cause said movable arms to move into a position wherein their claws engage in said lateral recesses, and thereafter exert a pressure uniformly distributed over the upper edge of said module to be plugged in whereby to plug the same into the bottom groove;

and two extraction hooks fixed to either end of the other grip element;

said hooks being so devised as to enable the opera tor, after he has turned the grip the other way round, to engage them into holes provided for the purpose in the module to be extracted and to thereafter unplug the same by squeezing the two grip elements together, said grip then reacting against the edges of the rack through the medium of two abutment members fast with that grip element which supports said movable claw-arms.

2. A device for plugging in and unplugging printedcircuit modules, as claimed in claim 1, wherein the movable claw-arms of each set thereof are independent of each other in that they are urged toward their respective resting positions by individual return springs and toward their fastening positions through the agency of a common transverse spring blade rigid with a central member which is hingedly mounted on a pivot common to the movable claw-arms and which is itself subjected to the direct action of the corresponding cam type actuating means.

, 3. A device for plugging in and unplugging printedcircuit modules, as claimed in claim 2, wherein each cam type actuating means is formed by a rod of which one end is fixed to that grip element which carries the two extraction hooks, said rod extending through the other grip element and having, protruding therefrom, firstly a frusto-conical camming portion which coacts with an abutment fast with the central member hingedly mounted between the movable claw-anns, and secondly a cylindrical portion provided on its free end with a thrust plate which, when the operator squeezes the two grip elements together, bears against the upper edge of the module to be plugged in.

4. A device for plugging in and unplugging printedcircuit modules, as claimed in claim 1, wherein the hooks on the extraction members are offset in such manner that the pull exerted by said extraction members be directed along the then coplanar centerplanes of the module to be unplugged and of the device itself, 7

supported on either end (if the grip, said posts having one of their ends fixed to that grip element which carries the movable claw-arms, extending through the other grip element the motion of which they serve to guide, and being extended by cap-forming members designed to react against the rack when the operator uses the device for unplugging a module.

Claims

1. A portable device permitting, as desired, either selective plugging in of a printed-circuit module into one of a plurality of bottom grooves formed in a rack and above which groove the module is restrained by lateral slideways, or selective unplugging of one of the modules plugged into the bottom rack grooves, said device comprising: a grip formed by two elements movable relatively to each other and normally held in mutually spaced relationship by return springs; two sets of movable arms pivotally mounted at either end of one of the grip elements; said movable arms being capable, in their resting position, of penetrating into the rack and being provided with claws capable of engaging into lateral recesses provided for the purpose in the side walls of the rack; two cam type actuating means so devised that when the operator moves the two grip elements toward each other they initially cause said movable arms to move into a position wherein their claws engage in said lateral recesses, and thereafter exert a pressure uniformly distributed over the upper edge of said module to be plugged in whereby to plug the same into the bottom groove; and two extraction hooks fixed to either end of the other grip element; said hooks being so devised as to enable the operator, after he has turned the grip the other way round, to engage them into holes provided for the purpose in the module to be extracted and to thereafter unplug the same by squeezing the two grip elements together, said grip then reacting against the edges of the rack through the medium of two abutment members fast with that grip element which supports said movable claw-arms.

2. A device for plugging in and unplugging printed-circuit modules, as claimed in claim 1, wherein the movable claw-arms of each set thereof are independent of each other in that they are urged toward their respective resting positions by individual return springs and toward their fastening positions through the agency of a common transverse spring blade rigid with a central member which is hingedly mounted on a pivot common to the movable claw-arms and which is itself subjected to the direct action of the corresponding cam type actuating means.

3. A device for plugging in and unplugging printed-circuit modules, as claimed in claim 2, wherein each cam type actuating means is formed by a rod of which one end is fixed to that grip element which carries the two extraction hooks, said rod extending through the other grip element and having, protruding therefrom, firstly a frusto-conical camming portion which coacts with an abutment fast with the central member hingedly mounted between the movable claw-arms, and secondly a cylindrical portion provided on its free end with a thrust plate which, when the operator squeezes the two grip elements together, bears against the upper edge of the module to be plugged in.

4. A device for plugging in and unplugging printed-circuit modules, as claimed in claim 1, wherein the hooks on the extraction members are offset in such manner that the pull exerted by said extraction members be directed along the then coplanar centerplanes of the module to be unplugged and of the device itself, respectively.

5. A device for plugging in and unplugging printed-circuit modules, as claimed in claim 1, wherein the return springs which urge the two grip elements away from each other are coil springs which surround posts supported on either end of the grip, said posts having one of their ends fixed to that grip element which carries the movable claw-arms, extending through the other grip element the motion of which they serve to guide, and being extended by cap-forming members designed to react against the rack when the operator uses the device for unplugging a module.