US 3819006 A
This specification discloses a loudspeaker cabinet comprising a frame on which is mounted a plurality of spherical receptacles in alignment with each receptacle having a loudspeaker mounted therein and a sound reflector common to all of the speakers and consisting of a generally oval shape fiberglass member presenting a compound concave reflecting surface characterized by a central apical ridge that is located closely adjacent to the loudspeakers.
Description (OCR text may contain errors)
PAIENTED E 5 I974 SHEUZBFZ LOUDSPEAKER CABINET WITH SOUND REFLECTORS BACKGROUND OF THE INVENTION In the co-pending application above identified there is disclosed a loudspeaker cabinet comprising a frame in which is mounted a spherical receptacle containing two loudspeakers in angularly spaced relation with a sound reflector associated with each loudspeaker Each sound reflector is of fiberglass and presents a compound reflecting surface comprising an inner concave conical section terminating in a point and an outer annular concave surface which joins'in with the inner section at an apical line. The point of each sound reflector partially enters a loudspeaker.
While the aforesaid loudspeaker cabinet with its sound reflectors is adapted to meet many conditions of usage, there are other conditions which are not completely satisfied thereby. Thus there are occasions when it is desirable to locate a plurality of loudspeakers at the'lateral or peripheral boundary of a particular area or space so that the sound therefrom is reflected and dispersed throughout the space with a fairly uniform degree of concentration over the entire area.
OBJECTS OF INVENTION With the foregoing conditions in mind, the present invention has in view the following objectives:
1. To provide, a loudspeaker cabinet and sound re flector assembly which includes a plurality of loudspeakers arranged in alignment together with a sound reflector that is common to all the speakers.
2. To provide, in a loudspeaker cabinet and sound. reflector assembly of the type noted, a frame in which is mounted a plurality of spherical receptacles in alignment with a loudspeaker mounted in each receptacle and with the loudspeakers in alignment. I 3. To provide, in an assembly of the character aforesaid, a sound reflector of fiberglass and having a compound reflecting surface comprising inner and outer sections. Each of these sections is of generally oval configuration with the inner section terminating in an apical ridge which isdisposed closely adjacent to all of the loudspeakers.
Various other more detailed objects and advantages of the invention, such as arise in connection with carryingout the above ideas in a practicalembodiment, will, in part, become apparent and, in. part, be hereafter stated as the description of the invention proceeds.
SUMMARY OF THE INVENTION The foregoing objects are achieved by providing a loudspeaker cabinet comprising a generally rectangularly shaped frame in-which is mounted'a plurality of spherical receptacles in alignment. A loudspeaker is assembled in each receptacle and opens onto the external surface of the receptacle. These loudspeakers are also in alignment.
Mounted on the frame is a fiberglass sound reflector presenting a compound concave reflecting surface comprising inner and outer sections. Each of these sections is of generally oval shape but is more particularly identified as being defined by straight sides and curved ends. Thus, the inner section has a concave reflecting surface generated by moving an arc of a circle about and within the periphery of the inner section. The two sections of the reflecting surface meet and merge in with one another at the periphery of the inner section. Theperiphery of the outer section is provided with an outstanding flange which constitutes means for mounting the sound reflector in the frame.
For a full and more complete understanding of the invention, reference may be had to the following description and accompanying drawings wherein:
FIG. 1 is a perspective of a loudspeaker cabinet and sound reflector embodying the precepts of this invention.
' FIG. 2 is a detailed section on an enlarged scale through one of the assemblies for mounting a spherical receptacle in the frame. This sectional view is taken from the area encircled by the broken line marked 2 in FIG. 1.
FIG. 3 is a side view partly in section and partly in elevation and is taken on the plane of the line 33 of FIG. 1.
FIG. 4 is a detailed section through one of the receptacles and loudspeaker carried thereby.
FIG. 5 is a perspective of the sound reflector per se; and
FIG. 6 is a detailed transverse section through the sound reflector being taken on the plane of the line. 6-6 of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing wherein like reference characters denote corresponding parts throughout these several views and first more particularly to FIG. 1, a loudspeaker cabinet made in accordance with the principles of this invention is shown as including a frame which is referred to in its entirety by the reference character 10. For the purposes of this specification, the frame 10 will be described as in a vertical position as such a position is believed to be preferred for actual usage of the cabinet. Frame 10 comprises a front bottom cross strut 11, front side struts 12, and a front top cross strut 13. Extending rearwardly from the lower ends of each strut 12 are bottom side struts l4 and extending rearwardly of the upper ends of side struts l2 and upper side struts 15. Connecting to the ends of bottom side struts l4 remote from side struts 12 is a rear bottom cross strut 16 while a top cross strut 17 extends between the ends of the top side strut l5 remote from struts 12. Rear side struts 18 extend between the ends of rear cross struts l6 and 17.
It is evident that the struts ll, 12 and 13 define a front framework substantially within a plane. Mounted in this front framework bya plurality of mounting assemblies to be later described are a plurality of spherical receptacles 19, 20 and 21. In this connection it is noted that. while three of these spherical receptacles are herein disclosed, the invention is not to be limited It will be understood that the receptacles 19,20 and 21 are identical hence only one of them is herein described in detail as that is believed to be sufficient for the purposes of this specification. Referring now more particularly to FIG. 4 receptable is shown as being of plastic with fiberglass being indicated as a preferred material. Receptacle 20 is formed with an opening at 9 behind which is mounted a loudspeaker designated generally 22. Loudspeaker 22 includes a conical member 23 which is secured to receptacle 20 at the periphery of opening 9 as by the fastening elements indicated 8. As shown in FIG. 1 receptacle 20 is mounted between side struts 12 by a pair of mounting assemblies each of which is referred to in its entirety of reference character 24. One of these fastening assemblies 24 is shown in detail in FIG. 2. Thus a side strut 12 is of sheet metal and is rectangularly in horizontal cross section. This strut 12 is formed with a pair of openings and mounted therein is a sleeve 25. Received in sleeve 25 is a screw bolt 26 having a head 27 with a gasket 28 being interposed between head 27 and strut 12.
Receptacle 20 is formed with an opening 7 through which passes a screw bolt 29 having a head 30 with a gasket 31 being interposed between head 30 and the inner surface of receptacle 20. A packing 32 covers the exterior of receptacle 20 about opening 28 and outside of packing 32 is a reinforcing plate 33. Screw bolt 29 passes through aligned openings in packing 32 and reinforcement 33. A spacer sleeve 34 having a threaded bore 35 is interposed between strut l2 and receptacle 20 with a gasket 36 at each end. Screw bolts 26 and 29 are threaded into spacing sleeve 34 a required degree to achieve an accurate positioning of the receptacle 20 with respect to the adjacent strut 12.
Receptacle 19 is anchored to struts 12 and front bottom strut 11 by similar mounting assemblies 24. Receptacle 21 is secured to struts l2 and front top strut 13 by the same assemblies. A sound reflector is illustrated per se in FIG. 5 and is identified in its entirety by the reference character 37. It is of fiberglass and comprises an inner section 38 and an outer section 39. Inner section 38 has a periphery defined by straight sides 6 and curved ends 40. This configuration might be said to be generally oval but is not a true oval because of the straight sides 6. Inner section 38 has an apical ridge 41 which it will be noted from FIG. 3 is closely adjacent to the conical elements 23 of loudspeakers 22.
The inner section 41 has a concave reflecting surface 47 generated by moving an arc of a circle with one end of the arc following the periphery made up of lines 6 and and at the other end of the arc a line which determines the ridge 4].
Outer section 39 has a concave reflecting surface 48 which is generated by moving one end of an are along lines 6 and 40 with the other end of the arc determining the outer periphery of this section which includes straight sides 42 and rounded ends 43. A flange 44 extends outwardly from the outer periphery of section 39 and is formed with openings 45. As shown more clearly in FIG. 1 fastening elements 46 pass through these openings and corresponding openings in rear struts 16, 17 and 18 to securethe reflector 37 in position in frame 10.
OPERATION While the manner in which the subject loudspeaker cabinet and sound reflector functions is believed to be obvious from the illustrations of the drawings and descriptions of parts set forth above, it will be briefly described by noting that sound waves from the loudspeakers 22 engage reflector 37 and are reflected therefrom about the receptacles 19, 20 and 21 into the area at one side of which the cabinet is located. The relation of the receptacles. and the reflecting surface of sections 38 and 39 afford an efficient and even distribution of the sound wavesover this area.
It is notable that while the lines 6 and 40 which define the periphery of the inner section 38 and inner edge of outer section 39 such lines are barely if at all discernable in the actual sound reflector because these sections 38 and 39 are integral with one another they is not to be limited to the exact construction, devices and mechanisms illustrated and describedbecause various modifications of these details may be provided in putting the invention into practice.
What is claimed is:
1. In a loudspeaker cabinet a. a frame,
- b. a plurality of spherical receptacles mounted in said frame in alignment,
c. a loudspeaker in each of said receptacles opening into the outer surface of the receptacle in which it is mounted, said loudspeakers being in alignment, and
d. a generally oval shaped sound reflector mounted in said frame and having a compound concave reflecting surface including an apical ridge which is disposed closely adjacent to said loudspeakers, said sound reflector comprising integrally joined inner and outer sections, said inner sections being generated by moving one end of an arc of a circle along said apical ridge and the other end of the arc along straight side lines and rounded end lines which determine the periphery of said inner section, said outer section being defined by an inner periphery comprising said straight side lines and rounded end lines and an outer periphery of straight side lines and rounded end lines, the concave surface of said outer section being generated by moving an arc of a circle along the peripheries of said outer section, with the outer section extending in a direction away from the periphery of the inner section and in the general direction of said apical ridge.
2. The loudspeaker cabinet of claim 1 in which the frame comprises a rectangular front framework and a rear rectangular framework joined to the front framework by struts with the receptacles being mounted in the front framework and the sound reflector in the rear framework.