U.S. patent number 3,866,712 [Application Number 05/462,373] was granted by the patent office on 1975-02-18 for collapsible speaker extension.
Invention is credited to James A. Carruthers.
United States Patent |
3,866,712 |
Carruthers |
February 18, 1975 |
COLLAPSIBLE SPEAKER EXTENSION
Abstract
A collapsible extension for an acoustical speaker including a
substantially planar top and a pair of opposed sides hingedly
connected to opposite edge margins of the top. Each of the sides
comprises at least a pair of panels hingedly interconnected at a
pair of their adjacent edges. Each side is adapted to be collapsed
by folding one panel back against the other and swinging the panels
into a position adjacent and parallel to the top. In operation, the
side panels are swung outwardly into planes extending in a common
direction away from the top. Bracing members interposed between
opposite sides are operable to maintain a preselected distance
between the sides. Tension members, such as screw rods,
interconnect the opposed sides and are operable to urge them toward
each other, both to clamp the sides against opposite side margins
of a speaker, and further to tighten the side margins against the
bracing members to rigidify the structure.
Inventors: |
Carruthers; James A.
(Warrenton, OR) |
Family
ID: |
23836208 |
Appl.
No.: |
05/462,373 |
Filed: |
April 19, 1974 |
Current U.S.
Class: |
181/178; 181/152;
181/30 |
Current CPC
Class: |
G10K
11/28 (20130101); H04R 1/021 (20130101) |
Current International
Class: |
G10K
11/28 (20060101); G10K 11/00 (20060101); H04R
1/02 (20060101); G10k 011/10 () |
Field of
Search: |
;181/178,189,190,152,30,182 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Tomsky; Stephen J.
Attorney, Agent or Firm: Kolisch, Hartwell, Dickinson &
Stuart
Claims
1. A collapsible extension for an acoustical speaker comprising a
substantially planar top member having opposed marginal edge
portions, a first side pivotally connected to one of said edge
portions and a second side pivotally connected to the opposite edge
portion of said top member, said first and second sides being
swingable toward and way from each other between operative
positions disposed at substantial angles relative to said top
member and extending outwardly in a common direction from the top
member and closed positions disposed substantially parallel to and
adjacent said top member, substantially rigid spacer means
insertable between said sides when said sides are in their
operative positions, operable to inhibit swinging of said sides
toward each other to maintain a preselected spacing therebetween,
and detachable tension means interconnecting said sides operable to
draw said sides toward each other
2. The extension of claim 1, wherein a side includes a plurality of
substantially planar, adjacent side sections hingedly
interconnected along an adjacent set of edge margins thereof
permitting said sections to swing relative to each other between an
operative position extending outwardly in opposite directions from
said hinge connection therebetween to lie in a substantially common
plane, and a storage position folded back against
3. The extension of claim 2, wherein one of said sections is
hingedly connected to said top member along an edge of said section
opposite its
4. The extension of claim 1, wherein said opposed sides and said
spacer means include means thereon for securing said spacer means
against removal when said tension means is operative to hold said
sides against said
5. The extension of claim 3, wherein said sectionalized side when
swung to its stored position is disposed contiguous a planar
surface of said top member and the other of said sides is hingedly
connected in a region spaced from said top member a distance
substantially equal to the combined thickness of said plurality of
sections of the sectionalized side when folded together, whereby
when the extension is collapsed said sectionalized side is stored
intermediate said top member and said other side, with said top
member and other side disposed substantially parallel.
6. The extension of claim 1, wherein said opposed edge margins of
the top member diverge on progressing in one direction and said
sides when in their operative positions diverge from each other on
progressing in said
7. The extension of claim 1, for use with a speaker having a
certain height and width, the distance between said sides of the
extension at their most closely spaced edges when in their
operative positions being substantially equal to the width of the
speaker and the height of said sides along said edges being
substantially equal to the height of said speaker, whereby the
extension may receive a forward portion of said speaker between
said sides, with operation of said tension means being operable to
clamp the
8. The extension of claim 1, which further comprises elongate,
elastomeric strips are interposed between edge margins of said
sides and said top
9. The extension of claim 2, which further comprises an elongate,
elastomeric strip interposed between contiguous edge margins of
said side
10. A collapsible extension for an acoustical speaker having
opposed side margins and a top margin framing the front of the
speaker, said extension comprising
a substantially planar top member,
a pair of opposed sides pivotally connected to said top member
adjacent opposite edges thereof for swinging toward and away from
each other between operative positions disposed at substantial
angles relative to said top member and extending outwardly in a
common direction from the top member and closed positions disposed
substantially parallel to and adjacent said top member, said sides,
when in their operative positions, having rear edge margins which
are spaced apart a distance substantially equal to the width of
opposed side margins of the speaker,
detachable spacer means extending between said opposed sides
adjacent the front edge margins of the sides to inhibit swinging of
said sides toward each other and to maintain a preselected spacing
therebetween when said sides are in their operative positions,
and
detachable tension means interconnecting said sides adjacent their
rear edge margins for drawing said sides toward each other and
clamping them
11. The extension of claim 10, wherein said tension means comprises
a screw device connected adjacent one of its ends to one of said
sides, and connected adjacent its opposite end to the other of said
sides, which screw device is operable upon turning in one direction
to urge said sides
12. The speaker of claim 10, wherein said sides are connected to
said top member in such a manner that they diverge relative to each
other on progressing from their rear edge margins toward their
front edge margins.
13. The extension of claim 10, wherein said top member is connected
to said sides in such a manner that when said extension is secured
to a speaker the top inclines upwardly on progressing forwardly and
away from the
14. A collapsible extension for an acoustical speaker having
laterally spaced, substantially parallel side margins, said
extension comprising a pair of opposed, substantially planar side
panels having laterally spaced rear edge margins adapted to engage
said opposed side margins of the speaker with remainder portions of
said side panels projecting outwardly in a substantially common
direction from said speaker, detachable spacer means extending
between said opposed side panels adjacent their front set of edge
margins operable to prevent movement of said front edge margins of
the side panels toward each other beyond a preselected lateral
spacing to maintain such a preselected spacing between said sides,
and detachable tension means interconnecting said side panels
intermediate their front and rear edge margins for urging said side
panels toward each other to clamp their rear edge margins against
opposite side margins of the speaker.
Description
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to a collapsible extension for an acoustical
speaker.
Conventional acoustical speaker enclosures when used allow a large
part of the sound wave front exiting from the enclosure to bend
around the sides of the enclosure resulting in the destruction of
much of the wave front. Only a relatively small portion of the
original wave front, particularly in the lower range, thus is
effectively propagated freely away from the enclosure.
It has been discovered that the performance of acoustical speakers
housed in enclosures may be improved by the addition thereto of
extensions having walls which diverge on progressing outwardly from
the front of the speaker. Various extensions have been devised in
the past, however, such generally have been rather cumbersome to
handle and thus have not been acceptable to the industry because
they are not easily packed and carried from place to place. Such
packing and carrying often is required by musical, or other, groups
who travel between engagements in different locales.
A general object of the present invention is to provide a novel
extension for an acoustical speaker which controls the propagation
of sound wave fronts leaving the enclosure whereby the wave front
when it leaves the extension is considerably larger than when it
left the enclosure and thus breaks up less providing a larger
portion to propagate freely into the atmosphere.
Another object is to provide such an extension for an acoustical
speaker which, when in operative condition, is large enough to
surround the front of a speaker enclosure, yet which may be
collapsed to a compact storage condition without having to be
broken into several different parts.
More specifically, an object is to provide such an extension for an
acoustical speaker in which a pair of opposed sides are hingedly
connected to a planar top and the sides are swingable between
operative positions extending outwardly in a common direction from
the top and stored positions folded closely adjacent a planar
surface of the top.
A still further object is to provide such an extension for an
acoustical speaker wherein a side includes a plurality of side
panels hingedly connected to each other which may be folded over
against each other for yet more compact storage of the
assembly.
Yet another object is to provide an extension for an acoustical
speaker which includes substantially rigid spacer members extending
between opposed sides of the extension, and tensioning memembers
interconnecting opposite sides and operable to draw the two sides
tightly together against the spacer members thus to provide
additional rigidity in the structure and further to provide
clamping of the sides of the extension against the sides of the
speaker enclosure with which it is to be used.
Another object is to provide a relatively inexpensive
self-contained horn-type extension, or projector, for an acoustical
speaker which will readily fit on the front of an existing speaker
cabinet to provide noticeable increase in sound output and
projection and improvement in tonal quality, yet which, when not in
use, can be folded down into a relatively compact package for
carrying and storage. No tools are required for installation and no
modifications of existing speaker required.
DRAWINGS
These and other objects and advantages will become more fully
apparent when the following description is read in conjunction with
the drawings, wherein:
FIG. 1 is a perspective view of an extension constructed according
to an embodiment of the invention secured to the front of a speaker
enclosure;
FIG. 2 is a cross-sectional view taken generally along the line
2--2 in FIG. 1;
FIG. 3 is a front elevation view of the extension removed from a
speaker;
FIGS. 4 and 5 are illustrations of sequential steps in folding the
extension for storage or carrying; and
FIG. 6 is a top plan view of the extension taken along the line
6--6 in FIG. 3.
DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION
Referring to the drawings, and particularly to FIGS. 1 and 2, at 10
is indicated generally a speaker enclosure having opposed upright
sidewalls 12, 14, a top 16, a rear wall 18, and a front wall 20.
Front wall 20 may mount a forwardly facing speaker 22. An opening,
such as that indicated generally at 24 in FIG. 2, is provided in
front wall 20 through which sound waves may emanate from speaker
22. Conventional grill cloth 26 may be secured over front wall 20
and opening 24 for decorative effect. The extension of the
invention also may be used on speaker enclosures wherein the
speaker faces rearwardly in the enclosure and the enclosure acts as
a progressively expanding dual horn (also known as a folded W type
horn) for projecting sound emanating from the speaker through the
front of the speaker.
At 30 is indicated generally an extension constructed according to
an embodiment of the invention. The extension includes a
substantially, planar, rigid top member 32 having opposed side edge
margins indicated generally at 32a, 32b, a front edge margin
indicated generally at 32c and a rear edge margin indicated at 32d.
As is seen in FIG. 6, side edge margins 32a, 32b diverge on
progressing from rear edge margin 32d toward front edge margin 32c.
The rear edge 32d has a length which is slightly greater than the
side-to-side dimension of speaker enclosure 10.
A side 36 is pivotally connected to top 32 by a pair of hinges 38.
Side 36 comprises a pair of substantially rigid, planar side
panels, or sections, 40, 42. As is best seen in FIG. 1, side panel
40 has substantially parallel front and rear marginal edges and a
lower marginal edge which extends substantially normal to its front
and rear edges. The top edge margin of panel 40, however, is
inclined and diverges away from the lower edge margin of the panel
as it progresses from the rear edge of panel 40 to its forward
edge. The maximum length, or height, of panel 40 is less than the
side-to-side dimension of top member 32.
Lower side panel 42 is substantially rectangular and is hingedly
connected at its upper edge to the lower edge margin of panel 40 by
hinges, such as hinge 43 seen in FIGS. 2-5. The hinge connection
between panel 40 and top 32 is such that side 36 may be folded
upwardly and inwardly toward the underside of top member 32 with
the inner face of panel 40 fitting substantially flush against the
underside of top member 32. Panel 42 is hingedly connected to the
lower edge of panel 40 in such a manner that it may be folded back
against the planar side of panel 40 facing away from top member
32.
Secured to the underside of side margin 32a of top member 32 is an
elongate, rigid, spacer 50 which projects substantially normally
outwardly from the underside of top member 32. The height of member
50, from its top edge margin which joins to top member 32 to its
lower edge margin, is substantially equal to, or slightly greater
than, the combined thicknesses of panels 40, 42.
Another side for the extension, indicated generally at 52 is
hingedly connected to spacer 50 by hinges 56. Side 52 includes a
pair of substantially rigid planar panels, or sections, 58, 60.
panel 58 has opposed, upright, substantially parallel forward and
rear edges, and a lower edge which extends substantially normally
between its forward and rear edges. The upper edge of panel 58
inclines upwardly, and thus diverges, from its lower margin as it
progresses from its rear toward its forward edge. The total height
of panel 58 is somewhat less than the total height of panel 40
spaced opposite it in the structure. Panel 60 is substantially
rectangular and has substantially the same dimensions as its
opposite panel 42 in the structure.
The rear marginal edge of side 36, and the total height of the rear
marginal edges of side 52 and spacer 50, each are substantially
equal to the height of speaker enclosure 10.
As is best seen in FIG. 1, panel 60 is hingedly connected adjacent
its upper edge by hinges 61 to the lower edge of panel 58. The
hinge connection between panel 58 and spacer 50 permits side 52 to
be swung upwardly and inwardly toward the underside of top member
32. The hinge connection between panels 58, 60 permits panel 60 to
be swung outwardly and against the outer side of panel 58.
Strips of sponge rubber, or other suitable elastomeric material,
indicated generally at 64 in FIGS. 3 and 4, are secured to the
rear, inwardly facing edge margins of top member 32 and sides 36,
52 and bottom edge margins of panels 42, 60 to provide an airtight
seal between the speaker extension and the existing speaker and
between the speaker extension and the floor. Strips of firmer
rubber 65, or other suitable elastomeric material, (see FIGS. 4 and
5) are secured to the upper and lower edges of side panels 40, 58
to provide substantially airtight seals between adjacent sections
in the structure and to provide compresive stress in the hinge
joints to prevent rattles when in the operative positions shown in
FIGS. 1 and 3.
Referring to FIG. 3, it will be seen that panels 40, 42, 58, 60
have depressions 66 formed on their inner surfaces adjacent their
forward marginal edges. Elongate rigid bracing rods, or spacers, 68
having rounded ends are adapted to extend between and seat within
opposed depressions in the panels when the extension is set up in
its operative condition as illustrated in FIGS. 1 and 2.
Panels 40, 42, 58, 60 also have bores 70 extending therethrough at
intermediate regions of the panels. As is seen in FIG. 2, a
plate-like nut 72 having a threaded bore extending therethrough is
secured to the outer side of each of panels 40, 42 with the bore in
nut 72 aligned with a bore 70 in its associated panel.
An elongate crank rod 74, also referred to herein as a tensioning
means, extends through aligned bores 70 in opposed panels 40, 58
and another crank rod 76 extends through aligned bores 70 in panels
42, 60, and the threaded ends of these rods are screwed into nuts
72. Turning of the rods 74, 76 acts to urge the sides of the
speaker toward each other to clamp them against opposite ends of
spacers 68.
Explaining the operation of the extension, and referring
specifically to FIGS. 1 and 3, sides 36, 52 are swung to their
operative positions extended outwardly from top member 32 and they
are positioned with their rear marginal edges on opposite sides of
the front of speaker enclosure 12 with, for example, an overlap of
2-3 inches between the extension and the enclosure where the
speaker enclosure has generally height, width and depth dimensions
in the neighborhood of 48", 24", and 22", respectively. The edge
margin of top member 32 rests on the top of the upper edge of
enclosure 10. Spacer members 68 are placed in depressions 66 on the
inner faces of the side panels. Crank rods 74, 76 are inserted
through bores 70 in the side panels and are screwed into nuts 72 to
urge the side panels toward each other. As the side panels are
urged toward each other, the inner surfaces of the rear margins of
the side panels are clamped tightly against opposite sides of the
speaker enclosure. As the crank rods are tightened, the top member
also is pressed against the top of the enclosure to provide a tight
fit therebetween. The sponge rubber strips 64 provide a
substantially airtight connection between the speaker extension and
the enclosure and between the speaker extension and the floor.
Turning of crank handles 74, 76 also draws the side panels tight
against spacers 68 to add further rigidity to the extension and
also stresses the individual side panels for additional stiffness
and helps prevent rattles occurring at the hinge joints. The firm
rubber strips at the hinge joints in the structure aid in the
tensing of the extension structure to prevent rattles as well as
provide more airtight seals between the joints.
With the speaker enclosure and extension resting on a floor, or
other supportive surface, 80 a projector horn surrounding the face
of the speaker enclosure is formed.
Thus, in its operative position, the extension provides a
substantially rigid, horn-type projector for improving the sound
output, projection, and tonal quality of the speaker. It also
improves loudspeaker loading to reduce distortion of tone and
prolong speaker life.
To fold the extension for storage or carrying, crank rods 74, 76
are unscrewed and removed, spacers 68 are removed, and thereafter
the extension may be folded as illustrated in the sequential steps
of FIGS. 3, 4 and 5. Explaining further, and referring to FIG. 4,
after removal of rods 74, 76 and spacers 68, panels 42, 60 are
folded back against the outer surfaces of panels 40, 58,
respectively. Panels 40, 42 then are swung together upwardly and
inwardly against the underside of panel 32 as seen in FIG. 5.
Panels 58, 60 are swung together upwardly and inwardly against the
underside of panel 42, as shown in FIG. 5.
While a preferred embodiment of the invention has been described
herein, it should be apparent to those skilled in the art that
variations and modifications are possible without departing from
the spirit of the invention.
* * * * *