GB2135522A

GB2135522A - Improvements relating to printed circuit board guide systems

Info

Publication number: GB2135522A
Application number: GB08400041A
Authority: GB
Inventors: Bruce Anthony Clutterbuck
Original assignee: Critchley Bros Ltd
Current assignee: Critchley Bros Ltd
Priority date: 1983-02-11
Filing date: 1984-01-03
Publication date: 1984-08-30
Also published as: GB8400041D0

Abstract

A support frame of a printed circuit board guide system has a rail 1 to which is secured a board guide 4 by means of arms 3 snapping into position over an enlarged head 2 on the rail 1. The rail 1 has a longitudinal slot 5. Within this slot can be accommodated a spacer clip 7 which has fingers 9 extending upwardly from a plate 8. Extension of a screw 10 through the plate 8 will cause the fingers 9 to rise and thus fix the position of the guide 4 when the screw 10 is held tightly against the base of the slot 5. By this means the guide 4 can be fixed at any desired point along the length of the rail 1. <IMAGE>

Description

SPECIFICATION Improvements relating to card guide systems This invention relates to frame constructions as used for holding printed circuit boards or other generally flat plate-like electrical components.

Such a frame construction will incorporate support rails on which are mounted transverse guide members incorporating grooves or slots to receive an edge of a printed circuit board.

In some instances it is required that the boards should be spaced at regular intervals and the guide members can then be so shaped that when they abut one another they automatically create the required regular spacings between the grooves to receive the boards. However if, for some reason, it is required to increase the spacing or have varying spacings at intervals it may well be impractical to supply a number of card guides, each of which defines a particular possible spacing.

It is therefore an object of this invention to provide means for spacing card guides so that any required spacing therebetween can be achieved very readily.

Accordingly this invention provides a card guide system comprising a support rail having mounting means on which is mounted a connecting portion of a card guide, the support rail also incorporating a slot open at the end of the rail and extending along the length of the rail and defining a narrow mouth to the top surface along the length of the rail, and a spacer member comprising a plate portion narrow enough to slide along the slot in the rail but having a width greater than the mouth of the slot, one or more fingers carried by the plate portion and able to extend up through the mouth of the slot and adjustable fixing and release means enabling the spacer member to be secured at a required position within the slot with the finger(s) projecting therethrough.

With such a system a number of spacer members can be fixed in the slots in the rail between adjacent pairs of card guides. It is relatively easy to provide sets of spacing members which define a variety of possible required spacings.

It is preferred that the dimensions of the plate portion, extending fingers and fixing means of the spacer member are such that the extending fingers can be lowered within the mouth of the slot to be flush with or below the top surface of the rail upon release of the fixing means. When the extending fingers are lowered so that they do not project above the top surface of the rail they can be slid along readily to a desired position below an already fitted card guide. Operation of the fixing means will then raise the fingers to a position where they will block lateral movement of a card guide.

The fixing means ideally comprises a rotatable screw mounted in the plate portion of the spacer member. Ideally the fixing means will be situated between a pair of fingers extending up from either end of the spacer member.

The invention also extends to a spacer member for use in a card guide system as hereinbefore defined and comprising a plate portion carrying one or more upstanding fingers whose width is less than the width of the plate portion, and fixing and release means enabling the height of the plate portion to be raised or lowered with respect to a datum level.

The construction of the spacer member will preferably be as defined above.

The invention may be performed in various ways and a preferred embodiment thereof will now be described with reference to the accompanying drawings in which:~ Figure 1 is a cross-section through a support rail to which is attached a card guide and a spacer member of a card guide system of this invention; Figure 2 is a plan view of the system shown in Figure 1; and Figure 3 is a side view of a spacer member as shown in Figures 1 and 2.

A rail 1 of a support frame of the card guide system as shown in Figures 1 and 2 is formed with a recess incorporating an enlarged head 2 which is received between shaped arms 3 depending from a a card guide 4, so as to be a snap-fit. This particular support rail incorporates a slot 5 of a shape devised for certain fixing requirements which are not relevant to the present invention.

However the shape of the slot is such that inturned portions 6 at the top face define a narrow mouth. Received within the slot 5 is a spacer clip 7 incorporating a plate 8 which is wider than the mouth defined by the portions 6 and thus can sit immediately below these portions 6. As can be seen, with further reference to Figure 3, the plate 8 carries upturned fingers 9 which are narrower than the slot formed by the portion 6 and can thus project up through that slot. The screw 10 can be tightened with a screwdriver to force the plate 8 into abutment with the portions 6 so that the fingers 9 project as far as possible and thus prevent lateral movement of the card guide 4.

Since the card guides 4 are mounted on to the support rail 1 so as to snap into place they can be mounted after the spacer clips 7 have been fixed in required positions, such as by using a mounting jig which can be set at each of the positions required to achieve the necessary spacing between each adjacent pair of card guides. It should also be noted that the particular shape of the slot 5 in the support rail 1 in this example is such that when the screw 10 is fully retracted the plate 8 will rest on bosses 11 within slot 5 and the upstanding fingers 9 will then lie below the top surface of the support rail 1. The spacer clip can then be slid along the slot 5 without disturbing any card guides already mounted in position and can then be fixed in place by rotating the screw 10 between a pair of card guides which have already been positioned at a desired spacing.

It will be appreciated that the shape of the slot 5 in the support rail can take many forms so long as it traps the plate portion of the spacer clip 7 and provides a mouth through which the fingers 9 can extend.

Figure 4 illustrates an alternative shape for a rail 1 a for the card guide system. This has a slot 12 which receives the edges of the plate 8 of the spacer clip 7 which is fixed in position in the usual way by tightening the screw 10.

Claims

1. A card guide system comprising a support rail having mounting means on which is mounted a connecting portion of a card guide, the support rail also incorporating a slqt open at the end of the rail and extending along the length of the rail and defining a narrow mouth to the top surface along the length of the rail, and a spacer member comprising a plate portion narrow enough to slide along the slot in the rail but having a width greater than the mouth of the slot, one or more fingers carried by the plate portion and able to extend up through the mouth of the slot and adjustable fixing and release means enabling the spacer member to be secured at a required position within the slot with the finger(s) projecting therethrough.

2. A card guide system according to claim 1, wherein the dimensions of the plate portion, extending fingers and fixing means of the spacer member are such that the extending fingers can be lowered within the mouth of the slot to be flush with or below the top surface of the rail upon release of the fixing means.

3. A card guide system according to claim 1 or claim 2, wherein the fixing means comprises a rotatable screw mounted in the plate portion of the spacer member.

4. A card guide system according to any one of claims 1 to 3, wherein the fixing means is situated between a pair of fingers extending up from either end of the spacer member.

5. A card guide system substantially as herein described with reference to the accompanying drawings.

6. A spacer member for use in the card guide system of any one of claims 1 to 5, comprising a plate portion carrying one or more upstanding fingers whose width is less than the width of the plate portion, and fixing and release means enabling the height of the plate portion to be raised or lowered with respect to a datum level.

7. A spacer member according to claim 6, wherein the fixing means comprises a rotatable screw mounted in the plate portion of the spacer member.

8. A spacer member according to claim 6 or claim 7, wherein the fixing means is situated between a pair of fingers extending up from the two ends of the spacer member.

9. A spacer member for a card guide system and substantially as herein described with reference to the accompanying drawings.