US3377515A - Circuit card cage construction - Google Patents

Description

April 9, 1968 P. F. ERB 3,377, 15

CIRCUIT CARD CAGE CONSTRUCTION Filed Aug. 25, 1966 5 Sheets-Sheet 1 ;3';" Er mm a I [1 I I ['1/ m 3 4 Mai? E? 3 4! H H 1' H i"! .1 H I, H H LLM;T :I I T1 1 T E: WTTF -h I H 1! u M4. 3 M i I i i l: 1 I; a i w 5 E5. I 5%} ll d a TNvENToR fleaenf7 5 April 9, 1968 P. F. ERB' 3,377,515

CIRCUIT CARD CAGE CONSTRUCTION Filed Aug. 25, 1966 5 Sheets-Sheet f3 INVENTOR A?! i [M B% lw v NEY-S P. F. ERB

April 9, 1968 CIRCUIT CARD CAGE CONSTRUCTION 5 Sheets-Sheet 3 Filed Aug. 25, 1966 INVENTOR fn United States Patent ()fiiice 3,377,515 CIRCUIT CARD CAGE CONSTRUCTION P'eteiF. Erb, Huntington, N .Y., assignor to Potter Instrument Company, Inc., Plainview, N.Y., a corporation of New York Filed Aug. 23, 1966, Ser. No. 574,405 7 Claims. (Cl. 317-101) ABSTRACT OF THE DISCLOSURE A'printed circuit card assembly comprising at least two card retaining shelf assemblies having connector elements for fixing the assemblies in fixed relationship. Electric connector members are supported in position to engage edges of printed circuit cards.

This invention relates to circuit card cage constructions and, more particularly, it concerns an improved construction for printed circuit card cages or racks in which a plurality of cards are maintained in parallel relation to make electrical contact with connectors carried by the cage and engageable along one edge of the cards.

Printed circuit techniques are used in numerous forms of electric and electronic apparatus, particularly in electronic data processing apparatus such as computers and the like. In the practice of such techniques, a plurality of printed circuit cards, each carrying an individual circuit thereon, are supported in parallel relation to each other on a rack or cage having a plurality of contact carrying elements positioned to engage terminals along an edge of the cards when the cards are pushed intothe cage. In the past, printed circuit card cages of the type referred to have taken various structural forms, one such form being illustrated in Us. Patent 2,976,510 Blain.

In accordance with the present invention, an improved circuit card cage construction and method for its assembly is provided by which a minimum number of stock items are required to form substantially any desired card cage capacity. To this end, and in its basic form, the present invention contemplates the use of card support members each having an identical cross-section to facilitate their formation from a common extruded length, mounted between a pair of end plates punched to locate fasteners, such as self-tapping metal screws. The support member cross-section defines one or more relatively deep, narrow grooves shaped in such a manner that self-tapping metal screws extending through the end plates will engage and' firmly fix the members to the end plates by engaging the grooves longitudinally and yet provide means by which such necessary items as connector bars may be fixed by similar self-tapping metal screws extending transversely into the grooves along the length of the extruded support members. The members are further shaped to receive transversely ribbed, preferably plastic, members to provide parallel guide paths for receiving the upper and lower edges of the cards. Also, it is contemplated that an intermediate extruded support member may be provided so that any number of card tiersmay be provided without adding significantly to the inventory of stock required to form various capacity cages that may be required.

Among the objects of the present invention, therefore, are: the provision of an improved circuit card cage construction which is adaptable to numerous cage sizes and 3,377,515 Patented Apr. 9, 196$ shapes without requiring a separate inventory of stocked items to accommodate each size or shape; the provision of such a cage to support printed circuit cards by which assembly is facilitated with a minimum of costly machining; the provision of a cage of the type referred to which satisfies requirements for strength and precision while at the same time reducing manufacturing costs; and the provision of a unique method for manufacturing printed circuit card cages.

Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter and taken in conjunction with the accompanying drawings wherein like reference numerals designate like parts and in which:

FIG. 1 is a fragmentary perspective view of one form of circuit card cage in accordance with the invention;

, FIG. 2 is a fragmentary front elevation of the cage illustrated in FIG. 1;

FIG. 3 is a cross-section taken on line 3-3 of FIG. 2

FIG. 4 is a section similar to FIG. 3 illustrating a modified form of the present invention; and V FIGS. 5 and 6 are schematic sectional views illustrating various other forms of printed circuit card cages that may be provided in accordance with the present invention.

As shown in the drawings, and in particular, FIGS. 1 to 3 thereof, one form of the present invention is shown to include a pair of end plates 10 and 12 each provided with suitable means such as slotted flanges 14 for mounting on equipment with which the card cage is used. Also, each of the plates is drilled or punched to provide holes for receiving self-tapping metal screws 16 which secure the assembly of the card cage in a manner to be described more fully below. It will be noted that the pattern of holes for the screws 16 in one of the end plates 10, 12 is a mirror image of the holes in the other plate so that the holes in the plate 10 are aligned with the holes in the plate 12 when the plates are spaced in parallel relation to each other.

Extending between the end plates 10 and 12, in the embodiment of FIGS. 1 to 3, are top, bottom and intermediate shelf assemblies 18, 20 and 22, respectively, arranged to support a plurality of printed circuit cards 23 in mutual parallel relationship and in accordance with conventional practice. Also extending between the end plates and as shown in FIG. 3 of the drawings are top, bottom and intermediate support members 24, 26 and 28, respectively, for supporting connector bars 29. The construction of the connector bars 29 is conventional and, as will be noted in FIG. 2 of the drawings, each includes a slot extending along its front edge in which a plurality of resilient contact finger pairs 30 are provided to receive and make electrical contact with terminal portions (not shown) provided along the rear edge of the cards 23.

In accordance with the present invention, each of the support members extending between the end plates 10 and 12 is formed by the extrusion of such metals as aluminum, magnesium or alloys of these metals, through a die so that each support member has a uniform cross-section throughout it length. Moreover, it willtbe noted, par ticularly in FIG. 3, that the support members are formed by three extruded sections; that is, an extruded section A forming part of the top and bottom shelf assemblies 18 and 20, an extruded section B forming part of the intermediate shelf support 22, and an extruded section C forming the connector support members 24, 26 and 28.

As will-be readily apparentalso from FIG. 3 of the draw-'.

ings, the extruded section B is esentially an integral form of two sections A placed back to back. Both of these sections are provided with mutually facing grooves 32 to provide undercut tracks for receiving the edges 34 of transversely ribbed sheet members 36 which engage and support the upper and lower edges of the printed circuit cards '23. Because of the manner in which the grooves 32 receive the edges 34 of the sheets 36, it will be appreciated that the sheets may be assembled with the extrusions A and B by sliding the sheets 36 lengthwise of the members formed from these sections.

In accordance with an important aspect of this invention, each of the extrusions A, B and C have cross-sections shaped to define narrow, relatively deep grooves extending throughout their length. Hence, each of the extrusions A and B have such grooves 38 and 40 formed along opposite edges thereof. Further, it will be noted that the grooves 38 and 40 terminate in enlarged cylindrical portions 42 coextensive with the grooves. Because of this particular configuration of the grooves 38 and 40, in the extruded sections A and B, the self-tapping metal screws 16 extending through the end plates and 12 engage the enlarged portions 42 of the grooves in a direction extending longitudinally of the extrusions.

The extrusion C is similarly provided with a pair of grooves 44 each terminating centrally of the extrusion in enlarged cylindrical portion 45. The extrusions C are, therefore, capable of connection to the end plates 10 and 12 also by the self-tapping metal screws 16 in a manner similar to the connection of the extrusions A and B as aforementioned. In addition, however, the grooves in the extrusion C receive further self-tapping metal screws 46 to secure the connector members 29 to the support members 24, 26 and 28 formed by the extrusion C.

The embodiment of FIG..4 is similar in all respects to the embodiment of FIGS. 1 to 3 with the exception that, in this instance, only two extruded sections are employed, these sections being designated by the reference letters D and E. In this instance, the extruded sections D and E correspond respectively to the sections A and B of the embodiment of FIGS. 1 to 3 with the exception that the sections D and E each include as an integral part, a portion resembling the section C of the aforementioned embodiment which serves the function of the connector supporting members 24, 26 and 28. Also, it will be noted in FIG. 4 that the longitudinal groove 38 in sections A, B and C is not needed since the grooves 44 can be used to afix the sections D and E between the plate members 10 and 12. The embodiment of FIG. 4 possesses the advantage that only two different extruded sections are needed to form the double tier printed circuit cage illustrated in FIG. 4 along with the end plates 10 and 12. The embodiments of FIGS. 1 to 3, on the other hand, lend increased versatility from the standpoint of accommodating cards of significantly varying lengths.

It will be apparent that the present invention lends itself to the formation of printed circuit card cages of any desired capacity. In FIGS. 5 and 6 of the drawings, various arrangements are illustrated which employ the extruded sections D and E of FIG. 4, it being understood that the extrusion sections A-C of FIG. 3 can be used in a similar fashion. Hence, in FIG. 5, a card cage is provided in which one tier of cards 23 is accommodated. By selecting the proper end plate, it is merely necessary then to cut from extruded stock of indeterminate length a pair of members having the cross-section of the extrusion D. A pair of equal lengths of the transversely ribbed sheet 36 are then severed, also from stock of indeterminate lengths, and the severed lengths slid longitudinally into the undercut tracks provided by the grooves mutually facing grooves 32. After the sheet 36 is thus assembled in the extruded sections D to provide upper and lower shelf assemblies, the assemblies are secured between the plates 10 and 12 merely by drawing the self-tapping screws 16 into the cylindrical portions 42 and 45 of the grooves 40 and 44. After the extruded sections have been assembled to the end plates, the connector elements 29 are placed against the rear portions of the sections and self-tapping screws 46 drawn into the grooves 44 to secure the connectors in place.

In the embodiment of FIG. 6, the cage is shown in which three tiers of cards 23 are supported. The cage illustrated in FIG. 6 is identical in all respects to the cages previously described with the exception that two intermediate extruded sections D or E are employed to retain the intermediate tops and bottoms of the cards 23.

Hence, the present invention provides a printed circuit card cage construction and method of assembling such a cage which requires no machining operations other than that of cutting the extruded sections to length and prepunching the end plates 10 and 12. Accordingly, the cage can be customized to a particular size and shape without the necessity for maintaining a large inventory of stock items. Accordingly, the present invention provides an improved cage construction and method by which the above-mentioned objectives, among others, are completely fulfilled.

Since variations of the particular embodiments described and illustrated herein are contemplated and others will be apparent to those skilled in the art, it is to be understood that the foregoing description is illustrative of preferred embodiments only, not limiting, and that the true spirit and scope of the present invention is to be determined by reference to the accompanying claims.

The invention claimed is:

1. A circuit card cage construction for supporting a plurality of circuit cards in generally parallel spaced relation, and having a plurality of circuit card connectors in position to contact each of the cards along an edge there of, said cage comprising: a pair of end members and parallel support members extending between and secured to said end members, each of said support members having a uniform cross-section throughout its length, said crosssection being shaped to define deep, relatively narrow grooves whereby the connectors may be secured to said support members by self-tapping screws engageable in said grooves.

2. The apparatus recited in claim 1 in which the crosssection of said grooves is shaped to define enlarged portions to receive connection means projecting from said end members longitudinally of said support members for securing said support members to said end members.

3. The apparatus recited in claim 2 in which the crosssection of said support members is shaped to define further, undercut grooves for receiving transversely ribbed card retaining sheets.

4. The apparatus recited in claim 1 including additional parallel support members also having a uniform cross-section throughout their length, the cross-section of said additional support members defining undercut grooves for receiving transversely ribbed card supporting sheets.

5. A printed circuit card cage comprising a pair of end plates, at least two card retaining shelf assemblies extending between said end plates, connector elements for fixing said shelf assemblies and said end plates to each other, each of said shelf assemblies including a severed length of extruded stock and a severed length of transversely ribbed sheet material to engage the top and bottom edges of printed circuit cards and retain the cards in mutually parallel relation, said extruded stock having a cross-section to define an undercut track to engage said sheet material and narrow, relatively deep grooves to receive connector elements extending normally to said end plates, a plurality of electric connector members, and means to support said electric connector members in position to engage an edge of the cards.

6. The combination recited in claim 5 in which said electric connector member supporting means includes an extruded section having further grooves shaped to receive said connector elements for securement between said end plates, and also to receive transversely oriented selftapping screws for fixing said electric connector members thereon.

7. The combination recited in claim 6 in which said extruded section is separate from said shelf assemblies.

6 References Cited UNITED STATES PATENTS 3,200,361 8/1965 Schwartz et al. 317-101 5 ROBERT K. SCHAEFER, Primary Examiner.

J. R. SCOTT, Assistwmt Examiner.

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