Quartz oscillator plateholder

Aug. 12, 1947. l. r. morse 2,425,481

QUARTZ OSCILLATOR PLATE HOLDER

Filed Sept. 21, 1943

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ATTORNEYS

Patented Aug. 12, 1947

2,425,481

UNITED STATES PATENT OFFICE

2,425,,481

QUARTZ OSCILLATOR PLATEHOLDER

Louis R. Morse, New York, N. Y., assignor, by mesne assignments, to Reeves Hoffman Corporation, Carlisle, Pa., a corporation of Pennsylvania

Application September 21, 1943, Serial No. 503,246

Claims.

This invention relates to quartz oscillator plate holders and has for its object certain improvements in their construction.

Holders of various designs have been proposed for quartz oscillator plates. For the most part they are not readily assemblable or tend to fail in service. These holders are widely used in radio circuits, for example, transmitters and receivers in planes, tanks, field signal devices, etc., and are, therefore, subjected to considerable rough treatment. They must not only be weather-proof but must be able to withstand a great deal of rough treatment without impairing the frequency rating of the oscillator plate mounted therein.

I have discovered a holder which, for the most part, overcomes the disadvantages of the holders heretofore proposed. Its parts may be readily assembled to complete the holder and once put together the holder is sufficiently durable to withstand considerable rough usage without impairing the frequency value of its oscillator plate.

The quartz oscillator plate holder of the invention comprises a casing; a pair of external socket prongs secured to the casing; a pair of spaced sliding contacts in the casing, each sliding contact connecting with the base of a socket prong; a removable chase in the casing between the sliding contacts, the walls of the chase being provided with a plurality of projecting stops and the projecting stops being spaced in relationship to one another to accommodate a pair of electrodes, a quartz crystal oscillator plate and a spring conductor and to provide a free space between the walls of the case and the edges of the electrodes and oscillator plate, so that contact of the oscillator plate with the chase is limited to the projecting stops.

The invention will be better understood by referring to the accompanying drawing, taken in conjunction with the following description, in which:

Fig. 1 is a side view in cross-section of a holder illustrative of the invention;

Fig. 2 is a cross-sectional view on the line 2—2 of Fig. 1;

Fig. 3 is a cross-sectional view on the line 3—3 of Fig. 1;

Fig. 4 is a top plan view, with the top removed showing the casing of the holder and its interior before the chase assembly is inserted;

Fig. 5 is a cross-sectional view of the chase assembly before it is inserted in the casing;

Figs. 6 and 7 are side and end views, respectively, of the chase itself; and (Cl. 171—327)

Figs. 8 and 9 are side and end views, respectively, of one of a pair of electrodes going into the chase assembly.

The holder shown comprises a casing 19, a pair 5 of external socket prongs i I and ί 2 secured to the bottom of the casing, a pair of spaced sliding contacts (3 and 14 in the casing, a removable chase 15 in the casing between the contacts, a pair of electrodes 16 and 17, a quartz oscillator 10 plate i8 and a spring conductor 19.

The casing is made of suitable insulating and weather-proof material. It is provided at its bottom with a pair of holes 20 and 21 to receive the socket prongs, the lower ends of holes ter15 minating in enlarged recesses 22 and 23 and the upper ends of the holes in enlarged recesses 24 and. 2S to provide an intermediate raised abutment 26. The casing walls provide a hollow interior 27 to receive the sliding contacts and the 20 chase assembly. The end walls 28 and 29 of the casing are provided at their top with a pair of holes 39 and 31, respectively, each of which is snugly fitted with a threaded sleeve 32. The tops of the casing walls have an inner raised central 25 portion 35 adapted to fit into a complementary recessed portion 36 in a removable cover 37. A flexible washer or gasket 38 fits between the cover and the top walls of the casing. The cover is provided with a pair of holes 40 and 41 with en30 larged recesses adapted to receive the heads of screws 42 and 43 fitting in sleeves 32.

Socket prongs i 1 and 12 are provided with sprung retainer washers 45 and 46 adapted to fit in recesses 22 and 23. The prongs extend into 35 the bottom of the casing, their upper ends being threaded to engage nuts 47 and 48.

Sliding contacts 13 and 14 are zig-zag in shape as shown, so that their lower ends fit over the prongs. Nuts 47 and 48 are tightly screwed on 40 the prongs so that the sliding contacts and prongs are in electrical contact. The upper ends of the sliding contacts extend along the sides and midway of the walls of the casing, terminating just short of the tops thereof.

Chase 15 is shown in various views in Figs. 1-3 and 5-7. It consists generally of a rectangular frame with rounded outer corners. The chase is constructed of suitable insulating material, preferably with a high dielectric constant. Its walls 50 have a very special configuration to adapt it to the presently preferred practice of the invention. Side walls 59 and 51 are substantially parallel and of the same height. The lower wall 52 is provided with a protruding shoulder 53, which is 55 adapted to engage intermediate raised abutment

2,425,481 at the bottom of the casing, between nuts 47 and 48, and thus provide clearance spaces 54 and between the lower corners of the chase and the nuts and prongs. The lower wall is spaced between the side walls to provide clearance spaces on the sides thereof to accommodate the sliding contacts. The upper wall 60 is provided with an intermediate portion Bl, having a height less .than that of the adjoining wall portion, to provide clearance spaces 62 and 63 on the sides of the intermediate portion, likewise to accommodate the sliding contacts. Each of the inner corners of the chase has a small angular projecting stop 64 extending into the interior, thus providing a clearance space 65 along the major portion of the inside of each wall. These projecting stops function as guides and stops for the electrodes and oscillator plate.

Electrodes 16 and 17 may be of conventional metal construction, as shown. Each electrode is rectangular in shape and each corner of at least one side or face has a raised portion 79 which together provide a recessed portion 71 that extends across most of the side or face of the electrode to the edges thereof. When the oscillating plate is sandwiched between a pair of the electrodes with the recessed portions facing the oscillating plate, they provide air gaps 72 and 73, as shown more particularly in Figs. 2, 3, and 5, because the raised corner portions 70 of the electrodes bear against the oscillating plate at its corners.

Quartz crystal oscillator plate 18 is any conventional type or cut. The one shown is rectangular in shape, substantially of the size of the electrodes. As in standard holders, it is sandwiched between the electrodes.

Spring conductor 19 may also be of the conventional type. The one illustrated is generally rectangular in outline but somewhat smaller than the electrodes, with its center portion curved and bent upwardly as shown. The bent portion is sufficiently high to give it the required spring action to maintain electrical contact between it, its adjacent sliding contact and adjacent electrode, as well as to force and. maintain the other electrode in electrical contact with the other sliding contact.

In assembling the holder, the following procedure may be employed:

Socket prongs I j and 12, with washers 45 and 46 mounted thereon, are inserted in holes 28 and 21 in the bottom of the casing iO. Sliding contacts 13 and 14 are then passed into the casing so that their lower bent-over ends fit over the threaded ends of the socket prongs. Nuts 47 and 48 are screwed onto the ends of the prongs to make a tight electrical contact between the prongs and the contacts. Quartz oscillator plate 18 is sandwiched between electrodes 16 and 17, the electrodes being arranged so that their raised corner portions 70 bear against the oscillating plate at its comers. The electrodes and plate are placed in the interior of the chase 15 with spring conductor 19 resting on one or the other electrode. The resulting chase assembly is then inserted into the casing with protruding shoulder 53 of the chase pointed toward intermediate raised abutment 26 in the bottom of the interior of the casing. As the chase assembly is pushed into the casing, the spring conductor is in sliding engagement with one of the electrodes while the other electrode is in sliding engagement with the other sliding contact. When the chase assembly has been completely inserted, flexible washer or gasket 38 is placed in position, removable cover 37 is placed over the top of the casing and screws 42 and 43 are tightly screwed in sleeves 32. Recesses 22 and 23 in the bottom of the casing are preferably filled with a moisture proof sealing compound.

It will be clear to those skilled in this art that the holder of the invention may be readily and accurately assembled and that the oscillator plate may be mounted in such a manner as to assure its operative position under all conditions of actual use. The plate cannot slide away from its installed position. Gaps of predetermined size are always maintained about the plate, its edges as well as its faces. This novel construction assures a holder the oscillator plate of which effectively retains its frequency rating.