US1860960A - Telephone receiver - Google Patents

Description

May 31, 1932. w. G. SHULL TELEPHONE RECEIVER Filed Nov. 14, 1927 2 Sheets-Sheet 1 Imm- DJiuiam E. Ehull @M May 31, 1932. w. G. SHULL TELEPHONE RECEIVER Filed Nov. 14. 1927 2 Sheets-Sheet 2 Inuen ur-- imam ET. Shun WW?- Patented May 31, 1932 UNITED STATES PATENT .FFICE WILLIAM G. SHULL, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, T

ASSOCIATED ELECTRIC LABORATORIES, INCL, O1 CHICAGO, ILLINOIS, A CORPORA- TION OF DELAWARE TELEPHONE RECEIVER Application filed November 14, 1927.

My invention relates to telephone receivers and particularly to the type termed loud speakers.

One object of my invention is the design of an instrument which will be substantial and cheap to manufacture and one which will not require further adjustment after it has been properly assembled.

In the present instance, I have shown the speaker provided with a cone reproducer. The cone is connected to a reed which is anchored or firmly fastened at both ends. The connection from the cone is made to the central portion of the reed. A portion of the reed lies between the pole pieces of two per manent horse-shoe magnets and the central portion of the reed is encircled by two operating coils which are responsive to voice or similar currents causing the vibration of the reed. The operation of the reed in turn operates the cone which reproduces or magnifies the vibrations of the reed.

My invention is illustrated in the accompanying drawings, wherein:

Fig. 1 is a rear view of the loud speaker with the cover removed to show the arrangement of the operating parts.

Fig. 2 is a top view of Fig. 1 with the cone and felt ring shown in section.

Fig. 8 is a plan view of one of the operating coils showing the reed passing through the opening therein.

Fig. 4c shows the construction of the reed.

Referring to Figs. 1 and 2 it will be noted the cone and magnetic structure for operating it are mounted upon a base 50.

The support for the outer edge of the cone 1 consists of an upright 5 attached to the base by the two brackets 51 and 52 as shown. The support 5 is provided with a circular opening which is lined with a wide but lightweight felt washer or cushion 2 provided with the two rims or binders 4t and 6 also of felt. The rim 4 is glued to the inner surface of the opening in the upright 5.

The outer edge of the cone 1 which is preferably made of parchment is supported or imbedded in the cushion 2 as shown in Fig. 2.

The apex of the cone is provided with a threaded rod or pin 7 which is adjustably Serial No. 232,97fi.

held in place by the two nuts 8 and 9. The rod 7 is also attached to the reed 10 as shown in Fig. 2.

The magnetic structure for operating the cone 1 is mounted upon two angle supports 31 and by means of the screws 21 and 13 which are of suificient length to extend through the nuts 22 and 14 and pass through clearance holes in the supports 31 and 82 which are then clamped to the magnetic structure by the nuts and 61. The angle supports are in turn fastened to the base 50 by screws 3834 and nuts 3935.

The two permanent horseshoe magnets 23 and 24, the reed 10 and operating coils 410 and 41 are mounted between the two brass plates 11 and 12. The magnet 23 is provided with two L-shaped soft iron pole pieces 30 and 37, while the magnet 2a is likewise provided with two similar pole pieces 29 and 36. The poles of the magnets 23 are provided with clearance holes for the iron screws 25 and 28 which respectively engage the threaded opening in the pole pieces 37 and 30, thus firmly attaching the magnet and its pole pieces to the plate 12. The magnet 2% and its pole pieces are likewise firmly attached to the plate 11 by means of two screws 27 and 26.

The two coils l0 and 41 are each attached to a brass frame. As shown in Fig. 3, the frame 46 is provided with turned-over cars which grip the coil and hold it firmly clamped in place. The cars or extensions 71 rest upon the plates 11 and 12 as shown in Fig. 2. Each coil is provided with a rectangular opening 49 through which the reed 10 passes. The opening is of sufficient size to allow the reed to vibrate freely.

Each end of tl e reed 10 is provided with clearance holes 68 and 69 through which the screws 18 and 21 pass. One end of the reed is clamped between two spacing collars 15 and 16, while the opposite end is clamped between spacing collars 19 and 20. The two screws 18 and 21 pass through the two plates 11 and 12 and also through the openings in the reed 10. and by tightening the nuts 14; and 22 the entire structure is firmly clamped together, forming a single unit.

The two frames 46 and 47, holding the coils 40 and 41 respectively, are adjusted and held in place by the set screws 4243 and 44-45 which pass through the plates 11 and 12 as shown in Fig. 2. By means of these screws the coils can be so adjusted that the reed 10 is centrally located within the opening 49. For additional adjustment or alignment the shims 17 and 18 may be provided for positioning the reed 10 in relation to the pole pieces 30, 37, 29 and 36.

The pin 7 which connects the cone 1 to the reed 10 passes through an opening in the plate 11 and the space between the plates 46 and 47 which support the coils 40 and 41.

A terminal strip 53 of insulating material carrying the two clips 55 and 56 is fastened to the plate 12 by means of a screw 54. The windings of the coils 40 and 41 are connected to the clips which are in turn connected to a two-conductor cord 57. This cord may be connected to a radio receiving set or other device. The current received from such a device passes through the coils 40 and 41 and exerts a push-pull effect upon the reed 10 which in turn operates the cone 1 causing the sounds to be magnified or reproduced.

From the foregoing it will be noted that the apex of the cone 1 is supported by the rod 7 fastened to the reed 10 while the outer edge of the cone is supported or cushioned by the ring of felt.

The reed 10 has a central magnetic portion 63 of iron while the two end portions 62 and 64 are of non-magnetic material such as phosphor bronze. The three portions are joined by the sets of tongues and grooves 65 and 66 as shown in Fig. 4.

The joints are soldered to form a stiff and substantially a one-piece reed. As shown in Fig. 2 the tongues and grooves extend beyond the coils 40 and 41 far enough for the central magnetic portion 63 to be acted upon by the short portions of the pole pieces 36-37 and 29-30. This prevents the magnetic portion of the reed from being influenced by stray magnetic currents flowing across the poles of the magnets 23 and 24.

The end portions of the reed being of nonmagnetic material are not aflected by such current and consequently a clear free action of the reed takes place caused by currents acting upon its central portion.

By having the outer edge of the cone resting freely within the separate ring of yielding material allows the cone and magnetic structure to always remain in proper relationship or adjustment.

Any variation due to expansion or contraction is automatically taken up, as the edge of the cone is free to move and assume any position of rest within the supporting ring, as its edge is but slightly imbedded in the ring and in practice just enough to allow proper support and movement.

If the outer edge of the cone was rigidly fastened to the support, then any lack of proper adjustment will create a strain on one port-ion of the cone, causing distortion or lack of clearness in the reproduced sounds.

What is claimed is:

1. In an acoustic device, a frame havlng a fiat circular inner surface, a resilient lining secured to the inner surface of the frame solely through the medium of the surface on its outer circumference, and a cone shaped diaphragm frictionally supported by and freely movable with said lining.

2. In an acoustic device, a frame having a flat circular inner surface, a resilient lining secured to the inner surface of the frame solely through the medium of the surface on its outer circumference, and a cone the diameter of the base of which is slightly greater than the openin remaining in said frame after the lining is in place, said cone being inserted and held in place in the opening solely by slight compression of said resilient material against the outer periphery of the base of said cone.

3. In an acoustic device, a cone shaped diaphragm, a frame member having a cylindrical opening therein the diameter of which 18 at least twenty percent greater than that of the base of the cone, and a resilient substance secured to said frame and frictionally holding said cone in place within the opening.

4. In an acoustic device, a diaphragm, and means for supporting said diaphragm at its outer extremity, comprising, a frame lined with resilient material against which the diaphragm is held by slightly compressing the said resilient material between the outer extremity of the diaphragm and the inner extremity of said frame, the front and rear surfaces of said lining lying in parallel planes at right angles to the inner and outer surfaces of said lining, and being left free to move with the diaphragm an extent depending solely on the resiliency of the said lining.

In witness whereof, I hereunto subscribe my name this 9th day of November, A. D.

WILLIAM G. SHULL.

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