US 3302143 A
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Description (OCR text may contain errors)
Jan. 31, 1957 R- J. HARKENRIDER 3,302,143
REED RELAY ASSEMBLY HAVING IMPROVED MQUNTING MEANS 5 Sheets-Sheet, 1
Filed July 1, 1965 Jam 1967 R. J. HARKENRIDER 3,30
REED RELAY ASSEMBLY HAVING IMPROVED MOUNTING MEANS Filed July 1, 1965 I5 Sheets-Sheet 2 ATT Jan. 31, 1967 R. J HARKENRIDER 3,302,143
REED RELAY ASSEMBLY HAVING IMPROVED MOUNTING MEANS Filed July 1, 1965 3 Sheets-Sheet 3 all;
United States Patent 3,302,143 REED RELAY ASSEMBLY HAVING IMPROVED MOUNTING MEANS Robert J. Harkenrider, Winona, Minn., assignor to Waynco Inc., Winona, Minn., a corporation of Minnesota Filed July 1, 1965, Ser. No. 468,731 4 Claims. (Cl. 335-154) This invention relates to relays, and more particularly to glass reed relays.
Relays of this type generally include two overlapping, but spaced apart, magnetic cantilever switch blades sealed in a glass tube and actuated by a magnetic coil surrounding the tube.
Because of the trend toward cincuitry miniaturization, it is desirable to operate relays of this type with minimal power, and because of their fragility, provide maximum shock protection.
It is therefore a primary object of the invention to provide a glass reed relay wherein a unique means is used to concentrate the actuating flux in close proximity to the cantilever switch blades for optimum power utilization.
A further object of the invention resides in a novel means for mounting a reed relay switch for maximum shock resistance.
Another object of the invention resides in a novel mounting means which serves to increase the eificiency of the glass reed switch and also acts as a unique terminal clip for physically and electrically connecting the relay assembly to a printed circuit board.
A still further object of the invention resides in a new method of assembling a glass reed relay in a fast and efficient manner.
Other objects and advantages of the invention will become more apparent during the course of the following description when taken in connection with the accompanying drawings wherein:
FIG. 1 is a perspective view, partially in section, of the relay assembly of the invention,
FIG. 2 is a side elevation vie vi of the relay, partially in section.
FIGS. 3, 4 and 5 are perspective views of the relay sub-assembly components namely, the coil-form, terminal clips, and reed switch, respectively.
Turning now to FIG. 1, the relay, indicated by the numeral 10, includes a coil 11 wound on a coil-form 12, a glass reed switch 13, and metal terminal clips 14.
As shown in FIG. 3, the coil-form 12 is of conventional molded plastic construction having a generally rectangular body 15, flange ends 16, and a rectangular bore -17 extending therethrough. Coil 11 is wound on the coil-form 12 between the confining flanges 16 and power is supplied via terminals 18 (FIG. 1), only one of which is shown.
The glass reed switch 13 (FIG. 5) may be of the conventional type wherein a tubular glass envelope 19 surrounds and seals reed cantilever switch blades 20. Within the glass tube the inner ends of the switch blades overlap one another but are spaced apart as at 21 and have their outer ends extending outwardly of the glass envelope to form electrical leads 22 and 23.
As brought out hereinbefore, one of the major problems in the use of glass reed relays is to provide maximum power efficiency and at the same time provide maximum protection for the fragile glass envelope. To achieve these results and at the same time overcome the deficiencies of past reed relays, the present invention embodies a unique concept in the terminal clips 14 which not only provide a minimum reluctance magnetic circuit but optimum shock protection.
These clips, as shown in FIG. 1, are provided with a generally U-shaped end portion 24 havingua base 25, a longer side 26, and a shorter side 27. Extending outwardly at substantially right angles at the top of the longer leg 26 is a flanged lip 28 slotted at 29 (FIG. 4) in which the lead ends 22 or 23 of the reed switch are received as will be described later.
For the purpose of providing a minimum reluctance magnetic path, the short leg 27 has a right angle extension 30 which acts as an iron bar to concentrate the flux in close proximity to the spaced apart reeds 20. As shown in FIG. 2, two of the terminal clips 14 are used, one extending into the coil-form bore 17 from each end.
To concentrate the flux and direct it through the reeds and across the switch gap 21, the ends of the clip bars 30 terminate short of one another and have a space 31 between them. This causes the flux to take the path of least reluctance and travel through the reeds and set up opposite magnetic polarities in the blades 20 across the gap 21 thereby causing the blades to close when sufiicient power is applied to the coil. The spacing 31 between the bar ends 30 can of course be varied depending on the pull-in and drop-out characteristics desired of the relay.
Mounting of the terminal clips on a circuit board is accomplished by tabs 33 struck downwardly from the base 25 of the U portion of the clips. Such tabs are inserted in holes 34 (FIG. 1) in a circuit board 35, and, in the case of a printed circuit board as shown, the tabs then are bent under and soldered to make contact with the electrically conducting film path 36 shown in dotted lines on the boards underside.
When the tabs 33 are bent on the underside of the circuit board, the bar members 30 of the clips engage the wall 37 of the coil-form bore 17 to securely hold the coil-form against the board. At the same time, the height of the longer legs 26 of the clips is such that they hold the glass reed switch out on contact with the walls of the coil-form bore and spaced above the bars 30 as at 38 (FIG. 2). This latter feature provides very excellent shock protection since deformation of the coil-form itself will not disturb the reed switch and direct shock to the circuit board is damped by the spring characteristics of the clips before being transmitted to the switch. This is extremely important in transporation and other types of controls which are confronted with punishing shock and vibration conditions.
According to another aspect of the invention, as indicated at A in FIGS 2 and 4, assembly of the reed switch in the bore 17 of the coil is facilitated by having the long leg 26 of one of the clips bent outwardly at about angle with respect to the clip-base 25. In actual assembly, the un-bent terminal clip indicated at B at FIG. 2 is mounted on the circuit board first and its tabs 33 locked. One end of the coil-form 12 is then slid into position with the clip bar extending into the bore 17 and in engagement with the bore wall 37. The opposite terminal clip with the bent leg A is then moved into position and its bar portion inserted into clamping position in the coil-form bore 17 and the clip tabs 33 locked.
Reed switch 13 is then inserted from the end where the U-leg 26 is bent out as at A in FIG. 2 and lead 22 thereof nested in slot 29 of the opposite un-bent clip at B. After the reed switch is inserted, the bent leg 26 at A is turned upwardly (and substantially parallel to leg 27) and the free switch lead 23 nested in its slot 29. Both leads 22 and 23 are then soldered to the clips. Thus it will be apparent that the locking of the reed switch, coil and coil-form to the circuit board is accomplished in a very easy and practical manner.
While the clips 14 have been shown to be attached g by the tabs 33, they can be attached by other means such as eyelets or screws. Also, depending on the mag netic characteristics desired, the length of the clip bars 30 and magnetic properties thereof may be varied. Likewise, the angle of the longer clip leg shown at A may be varied to permit easy insertion of the reed switch. Of course, the invent-ion may take other forms than shown Without departing from the spirit of the following claims:
What I claim is:
1. A relay comprising,
a coil-form having a coil Wound thereon and a tubular opening therein defined by wall areas of said coilform,
a reed switch having leads extending from the ends thereof,
clips positioned adjacent the ends of said coil-form,
said clips having a generally U-shaped portion having a base and a pair of s ides with one side being shorter than the other, said shorter side of each of said clips having a bar portion extending outwardly therefrom and into said coil-form opening and clamping against a wall area of said opening, the longer 4 legs of said U-shaped portion engaging said switch leads and supporting said read switch in said bore, and
means mounting said clips.
2. A relay as claimed in claim .1 wherein said means for mounting said clips includes lbend-able tabs for connection to a circuit board.
3. A relay as claimed in claim 1 wherein said longer leg has an outwardly turned lip provided with a slot in which a lead of said reed is received.
4. A relay as claimed in claim 1 wherein said bar portions extending from the shorter leg of said clips on each end of said coil terminate short of one another Within the tubular opening of said coil-form.
References Cited by the Examiner UNITED STATES PATENTS 3,030,468 4/ 196 2 Donceel et al. 200-87 3,215,794 11/1965 Zielinski 200-87 BERNARD A. GILHEANY, Primary Examiner.
B. DOBECK, R. N. ENVALL, JR., Assistant Examiners.