US3736472A - Circuit board guide and support apparatus having improved fastenings for rigid assembly - Google Patents

Abstract

An improved circuit board guide includes an element which has a longitudinal board-receiving groove in the front surface and which has spaced, cylindrical protrusions on the back surface, each protrusion having a central bore therein which receives a mounting pin that is attached to a mounting bar. The cylindrical protrusions are received in recesses about the mounting pins to form a rigid structure that supports a circuit board along opposite longitudinal edges.

Description

United States Patent [191 Muldoon, Jr.

[ 51 May 29, 1973 [54] CIRCUIT BOARD GUIDE AND SUPPORT APPARATUS HAVING IMPROVED FASTENINGS FOR RIGID ASSEMBLY [76] Inventor; Edward M. Muldoon, Jr., 3817 Mistral Drive, Huntington Beach, Calif. 92649 [22] Filed: Oct. 4, 1971 [21] Appl. No.: 186,251

[52] US. Cl. ..3l7/10l DH, 317/100 [51] Int. Cl. ..II05k [58] Field of Search ..3l7/99, 100, 101 DH,

[56] References Cited UNITED STATES PATENTS 1/1966 Calebro ..3l7/100 12/1971 Wenz ..317/10O 3,212,568 10/1965 Frawley ..3l7/l00 FOREIGN PATENTS OR APPLICATIONS 1,361,752 4/1964 France ..317/101 PH Primary Examiner-Herman J. Hohauser Assistant Examiner-Gerald P. Tolin Attorney-A. C. Smith [57] ABSTRACT An improved circuit board guide includes an element which has a longitudinal board-receiving groove in the front surface and which has spaced, cylindrical protrusions on the back surface, each protrusion having a central bore therein which receives a mounting pin that is attached to a mounting bar. The cylindrical protrusions are received in recesses about the mounting pins to form a rigid structure that supports a circuit board along opposite longitudinal edges.

2 Claims, 2 Drawing Figures I CIRCUIT BOARD GUIDE AND SUPPORT APPARATUS HAVING IMPROVED F ASTENINGS FOR RIGID ASSEMBLY BACKGROUND OF THE INVENTION Certain known circuit board supports or guides suitable for stacking a large number of circuit boards in a small housing, or card cage," commonly rely on spring wire forms or sheet metal pieces to form the desired supports and guides for the circuit boards. One disadvantage encountered in guides of this type is that numerous fastenings to the surrounding housing are required to assure adequate rigidity and alignment of the guide grooves.

SUMMARY OF THE INVENTION The improved circuit board support and guide assembly includes two principal elements which may be assembled in multiple arrays to provide a versatile mounting structure for supporting circuit boards in close, spaced relationship. The guide element includes a longitudinal groove disposed in one surface to receive the edge of a circuit board and also includes mounting pylons or protrusions disposed in spaced relationship on the opposite surface. These protrusions include a central bore and are arranged to fit snugly into recesses mating mounting bars. The mounting bars may include a plurality of spaced recesses, each including a pin which protrudes from the base of the recess to engage the central bore in the corresponding protrusion of a guide element. Lateral slots on the guide elements which engage the mounting bars reduce rotational movement about the protrusions and thereby enhance the shear stability of the structure.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of the guide element and mounting bars; and

FIG. 2 is a perspective view of the guide element showing the constructional details of the pylons and slots on the rear surface of the guide element.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, there is shown a guide element 9 which includes a longitudinal groove 11 that may communicate at least with the entrance end 13 to form an edge-receiving guide for a circuit board 15. The guide element 9 may include at a location along the groove 11, say, near the entrance end 13 a lateral recess 17 in the groove which cooperates with a boardejecting or locking mechanism that forms no part of the present invention.

The guide element carries a plurality of spaced, cylindrical protrusions or pylons 21 on the reverse face, as shown in FIG. 2, which are arranged to fit into mating recesses 22 in the mounting bars 23. These pylons are spaced at selected intervals along the length of the guide element 9 and are, in part,.the means for attaching the guide element 9 to the mounting bars 23. These pylons 21 are press fitted into the mating recesses 22 of slightly smaller diameter in the mounting bars 23. Additionally, a spring pin 24 may be carried either by the guide element 9 for engaging the aperture 25 in the base of the recess 22 in the mounting bar 23, or preferably, the spring pin 24 may be carried by the mounting bar 23 to engage the central bore 26 in the pylon 21 of the guide element 9. This latter configuration is preferred for improved thermal conduction between pins and mounting bars that aids in reducing thermal softening of plastic materials typically used in the guide elements 9. In either configuration, the spring pin 24 may be a split drive pin that is snugly fitted into the bar 23 or element 9 which carries it, as the case may be.

Referring now to FIG. 2, the reverse side of the guide element 9 includes a recessed slot 27 having a width dimension 28 that is approximately equal to the width 29 of the corresponding mounting bar 23. The mating engagement of these lateral recessed slots 27 with the corresponding mounting bars 23 provides shear stability which aids in maintaining orthogonal orientation of the guide elements 9 and mounting bars 23. In addition, the mounting bars 23 may include tapped holes 31 in the ends thereof to facilitate attachment to an end plate or frame 36. Thus, in a typical application of the present invention, a pair of guide elements 9 are arranged to receive opposite edges of a circuit board and are pressfittedly attached to sets of mounting bars 23 on each side of the circuit board. For short circuit boards, correspondingly short guide elements 9 having only two pylons 21 may be used whereas for longer boards, longer guide elements 9 having three or more pylons 21 may be used. The set of mounting bars adjacent one edge of a circuit board and the set of mounting bars adjacent the opposite edge of the circuit board are attached to end plates or frames 36 which may also support an edge-receiving circuit board connector 35 at the distal end 33 of, and in line with, the longitudinal grooves 11 in the associated pair of guide elements 9. Adjacent pairs of guide elements 9 may be laterally spaced any selected distance as established by the spacing 37 between adjacent recesses 22 in the sets of mounting bars 23. In the preferred embodiment of the invention, the guide elements may be cast from such materials as glass-reinforced Nylon or Delrin and the mounting bars may be formed of aluminum or plastic, or the like, to provide a high degree of rigidity as well as slippery guide grooves to facilitate easy insertion and withdrawal of circuit boards. Of course, the pairs of guide elements 9 and the associated mounting bars 23 therefor may be oriented to permit either horizontal or vertical sliding movement of the circuit boards supported thereby.

I claim:

1. Circuit board support apparatus comprising:

a guide element having a longitudinally-oriented groove in one face thereof which is disposed to receive an edge of a circuit board therein;

said guide element including a plurality of mounting means on a second face thereof which is opposite said one face; and for each of said mounting means a mounting bar disposed in substantially perpendicular relationship to the groove in said guide element and being attached to said guide element by a corresponding one of said mounting means; said mounting means includes a recessed, lateral slot in said second face of the guide element, said slot having a width substantially equal to the width of said mounting bar and being in snug engagement therewith to prevent relative rotation of said intersecting 65 bar and element about the mounting means therebetween; said mounting means also includes a protuberance of selected external dimension on said second face of said element, and said bar includes in mating engagement with said pin, with said protuberance disposed within said mating recess.

2. Circuit board support apparatus as in claim 1 wherein said pin is resiliently biased in the radial direction resiliently engaging said mounting bar and said protuberance for snugly retaining said guide element and mounting bar against relative movement in a direction along the length of said pin.

Claims (2)

1. Circuit board support apparatus comprising: a guide element having a longitudinally-oriented groove in one face thereof which is disposed to receive an edge of a circuit board therein; said guide element including a plurality of mounting means on a second face thereof which is opposite said one face; and for each of said mounting means a mounting bar disposed in substantially perpendicular relationship to the groove in said guide element and being attached to said guide element by a corresponding one of said mounting means; said mounting means includes a recessed, lateral slot in said second face of the guide element, said slot having a width substantially equal to the width of said mounting bar and being in snug engagement therewith to prevent relative rotation of said intersecting bar and element about the mounting means therebetween; said mounting means also includes a protuberance of selected external dimension on said second face of said element, and said bar includes a mating recess which has an inner dimension substantially equal to said external dimension of said protuberance on the guide element and which snugly engages said protuberance in said recess; and said mounting means includes a pin centrally disposed within said recess in said mounting bar, and said protuberance on said second face of said guide element includes a centrally-disposed bore therein in mating engagement with said pin, with said protuberance disposed within said mating recess.

2. Circuit board support apparatus as in claim 1 wherein said pin is resiliently biased in the radial direction resiliently engaging said mounting bar and said protuberance for snugly retaining said guide element and mounting bar against relative movement in a direction along the length of said pin.

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