US 3760235 A
An amplifier unit casing comprising a recess located in the rear of and relatively close to a front panel of the amplifier unit and below the level of an upper portion of the front panel, the recess having a surface which is adapted for installation thereon of adjusting attachments including semi-fixed variable resistors and terminals to be electrically connected to a speaker, tape recorder, record player or the like, wherein each conductor connected to such terminal is led to a speaker, tape recorder, record player or the like through a conductor guide space extending continuously from the recess to the rear end of the casing and provided on the upper wall of the casing and below the level of the upper portion of the front panel.
Description (OCR text may contain errors)
111 3,760,235 1 Sept. 18,-1973 3,299,323 l/l967 2,588,082 3/1952 Brown.... 2,988,655 6/1961 Rudolph AMPLIFIER UNIT CASING HAVING RECESSED CONNECTOR TERMINAL SURFACE Higashiosaka;
0 M 4 7 ll N m m m T A m m a M h m M &T, o U l B M m mm N e w e m m A4 B w WW5 o mw ll ax E 1 R 9 E O9 ynW F5, mm" m mw 5 "St PAA ma.- d k M 0 we? fmMT m i mw r w a iKmH mm mm o Ahwk ,m a a g 0 oMfi K ,Hm mmmma wdmm m. 030 :l YKYMM [7 51 Inventors: Kazushi Takami,
 Assignee: Onkyo KabushikiKaisha,Osaka-shi,
[5 7] ABSTRACT An amplifier unit casing comprising a recess located in Japan  Filed: Mar. 8, 1972  Appl. No.: 232,795
the rear of and relatively close to a front panel of the amplifier unit and below the level of an upper portion of the front panel, the recess having a surface which is adapted for installation thereon of adjusting attachments including semi-fixed variable resistors and termi- 317/118, 317/101 CB 317/l20 nals to be electrically connected to a speaker, tape recorder, record player or the like, wherein each conduc- 174/60 H02b l/l0 174/50, 52 R, 59,
tor connected to such terminal is led to a speaker, tape recorder, record player or the like through a conductor guide space extending continuously from the recess to the rear end of the casing and provided on the upper wall of the casing and below the level of the upper portion of the front panel.
 Int.  Field of Search....................
174/60;317/99, 101 R, 101 CB, 118, 120, 122
 References Cited UNITED STATES PATENTS 3,307,080 Cody 317/101 CB 9 Claims, 3 Drawing Figures PATENTE SEP] 8 I913 AMPLIFIER UNIT CASING HAVING RECESSEI) CONNECTOR TERMINAL SURFACE CROSS REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of our copending application Ser. No. 50,07l, filed June 26, 1970, now abandoned.
BACKGROUND OF THE INVENTION In the conventional amplifier, a terminal plate having input and output terminals and the like connected thereto and an adjusting plate having semi-fixed variable resistors and the like connected thereto are connected to the rear end surface of a unit casing. When it is desired to connect a conductor from a speaker, tape recorder, record player or the like to a terminal on the terminal plate or to inspect the electric connections, or when it is desired to adjust the semi-fixed variable resistors, with the unit casing placed adjacent a room wall it is necessary for an operator to pullthe amplifier forwardly toward him from the place of installation and then perform whatever service is necessary by reaching across the amplifier. Such an assembly also requires the workman to, on the one hand, try to see to the rear surface which is remote from the front panel surface, or on the other hand, have to turn the amplifier over with its rear end surface up in order to achieve access to the amplifier. tend to gather together and thus become entangled, causing many inconveniences.
Particularly where the amplifier is built in a rack along with a tape deck, record player or the like, the desire for connection or inspection of said electric wiring or for adjustment of the adjusting attachments makes it necessary to pull the entire amplifier completely from the rack. Therefore, the adjustment or the inspection of terminal parts is inconvenient.
The present invention was conceived primarily to eliminate these disadvantages,.and as will become apparent later herein has been found to possessother certain distinct advantages.
SUMMARY OF THE INVENTION The present invention relates to an amplifier unit casing, characterized in that its constructed in a special shape such that adjusting attachments including semifixed variable resistors and terminals for connecting thereto wiring extending to a speaker, taperecorder, record player or the like can be located at particular positions.
In an amplifier unit casing according to the present invention, a terminal region having terminals thereon and an adjusting region having semi-fixed variable resistors and the like thereon are located in the rear of and relatively close to the front panel surface of the unit casing and below the level of the upper portion of said panel surface, with the result that connection of the wiring to the terminals, inspection of the electric connections and adjustment by the adjusting attachments can be easily and conveniently carried out from above the unit casing.
Further, the conductors extending from the speaker, tape recorder, record player or the like to said terminals are led through a conductor guide space located on the rear upper side of the unit casing, with the result that it is no longer necessary to pass wiring through the inner space of a complicated unit casing, thus saving much time and labor in manufacture and decreasing interference of the amplifier parts with the input.
An object of the invention is to provide an amplifier unit casing whereby connection of wiring to the speaker, tape recorder, record player or the like, inspection of the electric connections, and adjustment of semi-fixed variable resistors and the like can be conveniently effected.
Another object of the invention is to provide an amplifier unit casing in which the inner wiring from terminals to an amplifier or the inner wiring extending to various parts for operating an amplifier which are generally provided for on the front panel can be made shorter to decrease interference with the faint input current.
A further object of the invention is to provide an amplifier unit casing wherein conductors from the speaker, tape recorder, record player or the like are arranged to extend to terminals in an orderly manner by means of conductor guide spaces which are suitably divided by upstanding partition walls thereby avoiding entanglement of the conductors and assuring easier control thereof.
Still a further object of the invention is to provide an amplifier unit casing wherein the terminals and adjusting attachments are located close to the rear of a front panel surface and can be easily inspected even from directly above the front panel surface thus facilitating the installation of a relatively large number of terminals and adjusting attachments at a position close to the front panel surface.
BRIEF DESCRIPTION OF THE DRAWING FIG. I is a perspective view of an amplifier unit casing according to the present invention with a lid removed therefrom;
FIG. 2 is a front view of the amplifier unit according to the present invention;
FIG. 3 is a schematic longitudinal section of another amplifier unit casing according to the invention built in a rack with the portion of the casing shown in drawn position.
DESCRIPTION OF THE PREFERRED EMBODIMENT The mode of embodying the present invention will now be described with reference to FIGS. I and 2.
At a position rearwardly of and relatively close-to a front panel 15 of a stereo amplifier unit casing generally indicated at 12 which contains a preamplifier part and a main amplifier part, there is formed a recess 16 which is located below the level of the upper portion of the panel 15, it being noted that a side portion 13 of the casing that is located forwardly of the recess 16 serves mainly as a preamplifier space and that a'trailing side" portion 14 of the casing serves mainly as a main amplifier space. The recess 16 has an inclined surface 17 directed obliquely rearwardly and downwardly and merges with a bottom surface 18, and on these respective surfaces there are installed electric parts such as many terminals 19-26, adjusting attachments 27, change over switches 28 and plug receptacle 29.
The numeral 19 denotes an earth terminal; 20 and 20a, terminals for a record player; 21, a terminal for a tape deck; 22, a terminal for a tuner; 23, a terminal for a sound recorder; 24, a preamplifier output terminal;
25, a main amplifier input terminal; 26, a terminal for a speaker; 27, a semi-fixed variable resistor for input level control of the record player terminal 20, tape deck terminal 21 and tuner terminal 22; 28, a change over switch for direct connection and separation of the preamplifier output terminal 24 and a main amplifier input terminal 25 to be effected in the interior of the casing; and the numeral 29 denotes a plug-receptacle for an adapter.
An upper wall 14a of the casing 12 has a conductor guide space located in a plane beneath the level of the upper portion of front panel as clearly shown in FIG. 1, and includes partition means 30 for dividing this area into conductor guide spaces 31.
The conductors which extend from the respective terminals are led through the conductor guide 31 to a speaker, tape recorder, record player or the like. The numeral 45 denotes a lid for covering the conductor guide spaces 31 and 16, and includes an access aperture 45a.
The surfaces extending between the front 15 and a rear panel 48 of the casing 12 and including surfaces 17, 18 and 14a may be considered a shelf portion. In FIG. 3 the shelf portion would include surfaces 1 l7 and 118. The access aperture 45a is complementary in its expanse to the greatest expanse of the recess 16.
The front panel 15 is provided with the following knobs (FIG. 2).
The numeral 32 denotes a main switch; 33, a selector switch for selecting a record player, tape deck or tuner; 34, a mode switch for changing the conditions of use of the right and left speakers (right and left change over, etc.); 35, a volume control; 36, a balance control for right and left volume; 37, a treble control; 38, a bass control; 39, a frequency shift change over switch for shifting the turnover frequencies of tone controls 37, 38; 40, a muting switch for sharply decreasing volume; 41, a loudness switch for compensating the sense of hearing in the case of low volume; 42, a high cut filter; 43, a low cut filter; and the numeral 44 denotes a jack for a head set.
FIG. 3 shows that an amplifier unit casing 112 built in a rack 147 has been a little withdrawn for the purpose of the connection of the wiring to the terminals, inspection of the electric connection, and adjustment by the adjusting attachment. Therefore, it is realized by this figure that those operations can be easily performed.
Further, another mode of embodying the present invention is shown in this figure.
In this case, the surface on which electric parts such as terminals and adjusting attachments are fixed is constituted by an approximately horizontal surface 118. Furthermore, the surface in the rear of said horizontal surface may be constituted by a surface 117 directed obliquely rearwardly and upwardly, and electric parts such as terminals and adjusting attachments may be secured to said inclinedsurface 117.
In the present invention, since a conductor guide space 31 is provided at a position below the level of the upper portion of the front panel 15, conductors to be connected to the terminals can be led therethrough from the rear end of the unit casing to a position relatively close to the rear side of the front panel 15, and since they can be connected to the terminals at that place, there is an advantage that, by simply removing the lid 45, these conductors can be simply and firmly the casing. Thereafter, the access aperture 45a in lid 45 can allow simple connection checks without removing the lid entirely. The rear extremity of the lid includes dependent stops 45b which straddle the upstanding tongues 45c-45c associated with the rear wall 48.
Therefore, in an amplifier, the troublesome procedure for moving the casing needed where the rear panel thereof is close to a room wall is no longer necessary. Further, even in a case where it is not close to a room wall, it is no longer necessary to peep at the rear panel of the casing from across the upper surface thereof or to turn over the casing with its rear surface up. Further, inspection of the wiring and adjustment of the adjusting attachments provided in the recess 16 are quite easy.
Further, since the terminals and adjusting attachments, which are positioned at the side closeto the front panel surface 15, are provided in the recess 16 which is located below the level of the upper surface of the front panel 15, and since the conductors to be connected to the terminals are led from the conductor guide spaces below the level of the upper portion of the front panel 15, the shape of the whole casing is neat and such casing can be constructed in a compact form.
Particularly in a case where the unit casing 112 is built in a rack, as shown in FIG. 3, the terminals, adjusting attachments and wiring certainly do not form any interference because of their low position, and, moreover, when it is desired to perform connection, inspection or adjustment of the parts, it is not necessary to draw the unit casing completely or substantially completely from the rack 147, but it suffices for this purpose if the casing is withdrawn until the recess 16 is accessible whereupon operations such as inspection and connection of wiring can be fully performed.
Furthermore, since the terminals are provided at a position relatively close to the front panel 15, the interior wiring which leads to the preamplifier parts on surface 17 can be made relatively short, thereby decreasing interference with faint input current. Further, since the conductors are led across the depressed area of the main amplifier and are concentrated on the rear portion 14a of the casing it is not necessary for the wiring to pass through the casing interior so that manufacture is facilitated and there is little interference from the main amplifier.
Further, when the recess 16 in which the electric parts are secured is inclined as shown in FIG. 1 or in FIG. 3, the degree of bending of the conductors which lead to the terminals is decreased and damage caused particularly when shield wires are used is alleviated.
Whether the amplifier is positioned in a rack or not, a person can easily look at the inclined surface 17 or 117 by slightly turning his face forwardly, so that operator control and handling is facilitated. I
The present invention is also effective for use with a unit casing having only a preamplifier or a main amplifier.
What is claimed is: v
1. An amplifier structure adapted for connection to remote units, comprising a casing having a front panel provided with control means, a rear panel, a pair of side connected to the terminals from the upstream side of panels extending therebetween, a top portion, a cover for the top portion, an elongated depressed area having upstanding walls extending to the top portion, one of said walls being closer to said front panel and including connector means which extend parallel to said front panel, said top portion further including a front area lying in one plane and a rear area of greater longitudinal extent lying in another plane beneath said front area and means for supporting the cover at least above the rear area to permit conductors to extend thereacross and to communicate with said connector means in said depressed area. i
2. An amplifier structure as claimed in claim 1, wherein said cover includes means defining an opening therein complemental to said depressed area.
3. An amplifier structure as claimed in claim 1, wherein said cover is partially supported by said front area of the top portion.
4. An amplifier structure as claimed in claim 1, wherein the rear panel of said amplifier includes upstanding means preventing longitudinal movement of said cover.
5. An amplifier structure as claimed in claim 1, wherein the cover includes a trailing edge portion, said edge portion being provided with dependent means arranged to cooperate with said rear panel.
6. An amplifier structure as claimed in claim 1, wherein the cover is positioned between and confined by the side panels.
7. An amplifier structure as claimed in claim 1, wherein the rear area of the top portion includes parallel spacedly arranged partition means providing guide channels for said conductors extending across the rear area of the top portion.
8. An amplifier structure as claimed in claim 1, wherein a first of the upstanding walls of said depressed area is angularly disposed relative to the other of said walls.
9. An amplifier structure as claimed in claim 1, wherein at least one of said upstanding walls is provided with connector means.