US 1936396 A
Description (OCR text may contain errors)
Nov. 21, 19373.
E. c. JEFFERls LOUD SPEAKER Filed May 10, 1933 l L m N @t -J SLU am; n www n m N www kvm m. iw: H w- --T-J k m N u. :TM m ww m m\ \\N m an x5 .N @NPN Patented Nov. 2l, 1933 srarss PATEnT'Fria 4 Claims.
My invention relates to apparatus for radio reception and particularly the construction and arrangement of the essential elements of the sound reproducing device, whereby the acoustic effects may be advantageously varied.
As hereinafter described, my invention includes a sound reproducing device comprising an outer casing with a horizontal partition intermediate ci its height supporting a circular diaphragm presented in a horizontal plane beneath a circular opening in said partition, diaphragm being operatively connected with an electric motor for vibrating it with radio impulses; said partition supporting a track in concentric relation with the axis oi diaphragm, and what I term a bell-shaped throat which is a sector of a hollow parabolic shell h /ing at the lower edge thereoi means for engagi'v said track, whereby said throat may be Shiite circumierentially with respect to said track. to present its sound reflecting surfaces in any de ed direction within a' sound ampli hood i "ling the top of said casing and overl-ranging said throat and the parts connected therei Said hood is openv at one end for prcwction oi sound waves Vtherefrom under impulses from said diaphragm, and the purpose and effect of making said throat ad` justable as aforesaid in said hood is to vary the volume and tone oi the sounds thus projected, as hereinafter described.
My invention includes the various novel features oi construction and arrangement hereinafter more definitely specified.
In said drawing, Fig. I is a front elevation of hood and adjustable throat, the latter being in concentric relation with said hood and in the position to project the maximum volume of sound from the diaphragm. Fig. II is a vertical sectional view of said structure taken onthe line II, II, in Fig. I in the direction of the arrows on said line.
In said gures, said casing includes the base 1 supporting the iioor 2 and the outer shell 3 including the sound reilecting hood 4 at the top thereof. As indicated, the upper portion of said hood is half of a hollow cone having a rounded back, and
the side walls 5 and 6 oi said casing extend ver-y tically in connection with said conical portion so that the entire casing is designed for reflection and projection of sound in the direction to the left of Fig. II.
Said casing Walls 5 and 6 have inwardly eX- tending brackets Tand 8 supporting the partition 9 which is normally in stationary position in said said casing and its appurtenances, including said Said partition 9 is provided withA the circular track 14 in concentric relation with se :l open- 65 ing ll and the diaphragm i3 beneath it. The
bell-shaped throat l5 is a sector or" a hoilow parabolic shell having the inner sound reflecting surface 16 for projecting the sounds fr reproducer laterally with respect to said hood 4.
Said throat l5 has means for engaging said track 14, including the arcuate rib l'l and arcuate ange 18. It is to be understood 'that said throat 15 is readily movable circumferentially with respect to said track in concentric relation with the sound reproducing device so that, in the position shown, it projects the maximum volume of sound Waves toward the left in Fig. II in concentric relation with the outer hood 4 of aid casing. However, if said throat l5 ce reversed in positionto present its sound reflecting surface 16 at the left in Iig. II, the eiect to project the sound waves toward the bacln'ciosed, portion of said hood 4 and to Very materially minimize the volume of sound projected. rIhe acoustic effect of the cooperation ci said hood 4 and movable throat 15 may be advantageously varied by merely turning said throat l5 upon its track 14 so that the opera-tor may instantly and readily control and vary the volume and qua ity of the sound emitted from said casing independently of any electrical controlling means aplpurtenant to said sound reproducing device 12 and, of course, such mechanical variation of the volume and quality of the sound produced may be cooperatively employed in conjunction with any electrically operative means for controlling the volume and quality of the sound reproduced.
The electrically operative means above contemplated may be of anyconvenient form. For instance, in Fig. I, I have indicated a container 20 for the usual transformers and the container 21 for a series of evacuated bulbs containing electrodes, one such bulb being indicated at 22 in Fig. I. Said sound reproducing device l2 is connected with the contents of the casing 20 by the electrical conductors 24 and'25 and with the casing 21 by the electrical conductors 26 and 27,
and said apparatus is operatively connected with 11 the conductor 28 leading to any suitable antenna and with the ground conductor 29.
Said electrically operative means is conveniently supported by the iloor 2 within the compartment 30 of said casing shell 3, and I nd it convenient to normally maintain said compartment closed by the cover 31 which is norvmally held in the position shown in Fig. II by its opposite side flanges 32 and 33 which are indicated in dotted lines. Said cover 31 conveniently supports the knobs 35 and 36 by which the electrically operative means aforesaid may be manipulated.
Moreover, I find it convenient to provide the opening 37 in the back wall ol' said casing shell 3 with the door 38 which is fitted to slide to and from its closed position shown in Fig. II in the guide anges 39 and 40 which are iixed on said casing shell 3. Said opening 37 not only aords convenient access to the contents of said compartment 30, but may be used for Ventilating said compartment which becomes heated during the operation of the apparatus. Y
However, I do not desire to limit myself to the precise details of construction and arrangement herein set forth, as it is obvious that Various modifications may be made therein without departing from the essential features of my invention, as donned in the appended claims.
l. In a loud speaker for radio apparatus; the combination with a casing including means supporting a diaphragm in a horizontal plane, and
an electrically operative sound reproducing device for vibrating said diaphragm; of a horizontally extending track in concentric relation with said diaphragm at the top thereof and a bellshaped throat which is a sector of a hollow substantially parabolic shell, having means at its said diaphragm may be varied by varying the relative position of said throat in said hood.
3. In a loud speaker for radio apparatus, the combination with an outer casing having its upper portion forming the half of a hollow cone with a rounded back and its side walls extending vertically in continuation of said hood; of a horizontal partition in said casing separating said hood from the lower portion of the casing; said partition having a circular opening therethrough; a sound reproducing device supported by said partition and including a diaphragm presented beneath said opening in concentric relation therewith, and electrically operative means for vibrating said diaphragm; a track supported by said partition, at the top thereof, in concentric relation with saidk opening; and a bell-shaped throat which is a sector of a hollow substantially parabolic shell, having means at its lower edge for engaging said track in circumferentially adjustable relation therewith; whereby sound waves projected vertically from said diaphragm may be projected laterally in different directions in accordance with the circumferential position of said throat on said track and with acoustic eiects varying in accordance with the relative position of said throat in said hood.
e, In a loud speaker for radio apparatus, the combination with a sound reproducing device including a circular diaphragm and electrically operative means for vibrating said diaphragm; of a bell-shaped throat which is a sector of a hollow substantially parabolic shell; and means supporting said throat in coaxial relation with said diaphragmY and with freedom for circumferential adjustment with respect thereto; whereby sound waves projected into said throat parallel with the axis of said diaphragm may be projected laterally to said axis, from said throat, in different directions in accordance with the circumferential position of said threadincludng a sound reflecting hood overhanging said throat, in stationary relation with said sound reproducing device; whereby the volume and duality of sound projected from said hood in m0 waves formed by said diaphragm may be varied by varying the relative position of said throat in said hood.
l lll EDWARD o. JEFFERIS.