US2099727A

US2099727A - Telephone receiver

Info

Publication number: US2099727A
Application number: US719130A
Authority: US
Inventors: Archibald A Duncan
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-04-05
Filing date: 1934-04-05
Publication date: 1937-11-23
Anticipated expiration: 1954-11-23

Description

Nov. 23, 1937. A. A. DUNCAN 2,099,727

' TELEPHONE RECEIVER Filed April 5, 1954 30 33 ab 35 6 as aq a7 39 g 33 I I I 1 1716 6 7 11 15 b is 10 Hf y n" W il 'H 1 10 I I VLQJ l A n g? 25 5 :FIEB

IN VEN TOR a 2&2

A TTORNE Y Patented Nov. 23, 1937 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to improvements in magnetically operated sound reproducing apparatus and while intended for use generally wherever it may be advantageously employed, it is particularly adapted for use in telephone receivers and loud speakers in which connection it will be illustrated in the drawing and hereinafter specifically described.

Objects of the invention are to provide a loud speaking electric receiver of simple construction which may be manufactured at a low cost and which will be eificient in use.

Other objects of the invention are to provide a receiver including a diaphragm having electromagnetic means for vibrating said diaphragm and a permanent magnet for amplifying the force of the electromagnetic means and to provide an improved arrangement of parts whereby the permanent magnet will operate to greatly increase the effect of the electromagnet without in any way distorting or otherwise effecting the normal position of the diaphragm.

Other objects are to provide a sound reproducing device which will include a diaphragm, an electromagnet having an armature operatively connected to the diaphragm and a permanent magnet arranged to permanently maintain the armature in a magnetized condition and thereby provide an armature having polarized ends each positioned in opposite polar relation to the poles of the electromagnet.

The accomplishment of the above and additional objects is attained by the novel construction, combination and arrangement of parts hereinafter described and illustrated in the accompanying drawing wherein there is shown a preferred embodiment of the invention, it being understood that changes and modifications may be made or resort had to substitutions which come within the scope of the claims hereunto appended.

In the drawing:

Figure 1 is a central, vertical, sectional view of a loud speaking unit constructed in accordance with this invention,

Figure 2 is a plan view showing the cover and diaphragm removed.

Proceeding now to a detailed description of the invention with reference to the particular adaptation thereof disclosed in the drawing, the numeral 3 is used generally to denote a casing which is preferably formed of brass or other non-magnetic material. a The casing 3 is provided with a relatively small closed end portion 4 which is offset larger to provide an annular shoulder 5 and a relatively larger intermediate portion 6. The wall of the casing is offset larger at the end of the portion 6 to form the annular shoulder and the larger mouth portion 8.

The portion 4 is provided with an end wall 9 and an electromagnet I0 is suitably secured to the central portion thereof. As shown in the drawing, the magnet I0 consists of two coils Ma and lOb wound on a horseshoe core H. The forks of the core II project upwardly in spaced, parallel relation and terminate in outwardly turned horizontal portions Ila and Mb. The end portion ll forms the positive pole piece of the electromagnet l0 and the end portion llb the negative pole piece thereof. The ends of the wire'l2 forming the coils Illa and lflb terminate in suitable connecting terminals l3 and 14 whereby the same may be operatively interposed in an electric circuit.

The numeral I5 denotes a permanent horseshoe magnet which is positioned on the shoulder 5 and extends around approximately one-half of the circumference of the casing 3. The positive end of the magnet I5 is provided with a spring bracket I6 which is suitably secured to the inner side thereof and terminates in a horizontal portion which is positioned with the medial line thereof disposed along the diameter of the casing passing over the pole pieces I la and Nb. A relatively thicker soft iron pole piece I! is secured to the inwardly projecting portion of the bracket [6 to extend in the same general direction. The pole piece I! extends over the outer portion of the pole piece Ill) and is disposed in operative spaced relation thereto.

The negative end portion I5?) is provided with a similar bracket l8 which is suitably secured to the inner face thereof with the longitudinal portion of the bracket l8 positioned with the medial line thereof disposed on the same diameter of the casing as the bracket Hi. The numeral l9 denotes a negative iron pole piece which is similar to the positive pole piece I! and is secured to the inwardly projecting end of the spring bracket I8 to extend in the same general direction with the inner end thereof projecting over the outer portion of the pole piece Ha in operative spaced relation thereto.

The numeral 2!] denotes an armature of soft iron which is positioned between the pole pieces I! and I9 with the ends thereof in operative, spaced relation thereto. The numeral 2| denotes a thin brass spring which is secured to the amplified resulting in a louder,

pole'pieces l1 and I 9 and to the armature 20 to secure the same in an operative position. The spring brackets l6 and ii are composed of mag netically conductive material and V the said brackets and the'brass strip 2| support the armature 20 so that it may be freely vibrated when subjected to theintermittent attraction of the magnet 10.

The numeral 22 denotes a diaphragm which is preferably composed of mica, but which may be formed of any suitable material. The marginal portions of the diaphragm 22 are supported on the shoulder 1 between the

gaskets

23 and 24. V closure member 25 having a cylindrical flange is fittedrin the mouth portion 8 with the axial end thereof in forced contact with the gasket 24 thus firmly securing the diaphragm 22 in an operative position in the casing 3.

The numeral 29 denotes a connecting member.

which is threaded or otherwise secured to the armature 20 with the upper end thereof extending through the central portion of the diaphragm 22. V V

The connecting member-21 is securedto the diaphragm 22 by thenuts 28 and 29 which are operated to firmly secure the members 21 in place without normally distorting the diaphragm 22. The closuremember is provided with a suitableopening 3D which'may be provided with a suitablenipple 3|. o

In operation, the terminals l3 and H are operatively connected in a telephone circuit. 'When subjected to the action of an intermittent current the magnet 10 will be energized attracting the pole piece 20 and operatively vibrating the dia-' phragm 22. 7

1 Itwill be seen that the pole piece llw is positive, the pole piece l'9 negative and the polerpiece llb negative and the pole piece I 1 positive; the attraction of the electromagnet' III will be greatly tion of sound.- 3 V 7 It will also be seen that use of opposite polarization' to intensify the action of a permanent magnet has been accomplished without substan tial distortion of the diaphragm 22 when the 'electromagn'et is'not in operation thus providing an amplified receiver which will operate to preproduce sound without distortion.

clearer reproduc 1.'In a telephone receiver; an electromagnet:

' having a horseshoe core terminating at each end thereof in laterally projecting pole pieces, a soft iron armature positioned in spaced operative relation to said pole pieces, apermanent magnet having a spring bracket on each end thereof, a soft iron pole piece on each'bracket, said armature mounted with its ends in close, spaced relation to and in the lateral plane of the pole pieces of said permanent magnet, each pole piece of said permanent magnet being positioned 'in close spaced relation to the pole piece at the opposite pole of the electromagnet, a diaphragm and member operatively connecting the armature to the diaphragm.

' 2. In a telephone receiver, an electromagnet" having opposite poles presented in the same direction and having oppositely projecting flat pole pieces, a soft iron armature positioned in spaced operativetrelation to said pole pieces; a permanent horseshoe magnet, a spring :extension on each end thereof, a soft iron pole piece on the end of each extension, said armature mountedin spaced relation between said soft iron pole pieces; a thin strip of magnetically non-conductive maa terial connecting said armature to the soft iron pole pieces, a diaphragm and means operatively connecting said armatureto said diaphragm.

3. In a telephone receiver, an electromag et having opposite poles presented in the same direction and having oppositely projecting flat pole pieces, a soft iron armature positioned in spaced, operative relation to said pole pieces; a permanent horseshoe magnet, a spring extension on each end thereof, a soft iron'pole piece on the end of each extension, said armature mounted in spaced relation between said soft iron polepiec'es, ;a thin strip of magnetically non-conductive mapermanent magnet, a diaphragm and means 0p eratively ,connecting said armature to said diaphragm. V

ARCHIBALD A. DUNCAN.