U.S. patent number 3,850,392 [Application Number 05/320,553] was granted by the patent office on 1974-11-26 for equipment security device.
Invention is credited to James Scott Gassaway.
United States Patent |
3,850,392 |
Gassaway |
November 26, 1974 |
**Please see images for:
( Certificate of Correction ) ** |
EQUIPMENT SECURITY DEVICE
Abstract
A security device for protecting equipment such as typewriters,
calculators and the like comprises a flexible pad bondable by
adhesive to a mounting surface such as a table or desk, and a cover
having depending lugs having holes adapted to register with
corresponding loop devices protruding upward from the pad so that
lock pins may be passed through the lugs and loops, from openings
through the cover, to attach the cover to the pad. Locks are
provided to be inserted into the openings after the lock pins have
thus been introduced so that the pins cannot be retracted until the
locks are unlocked by a key. Means is provided for bolting the
equipment to the top of the cover from inside the cover before the
cover is attached to the pad. Thus there is no access to the bolts
holding the equipment until the locks are removed. The bonding
adhesive is so strong in tension that a person cannot lift it off
the mounting base. The pad can be removed from the mounting base
however after the cover is unlocked and removed, by peeling the pad
off the the base.
Inventors: |
Gassaway; James Scott (Los
Angeles, CA) |
Family
ID: |
23246934 |
Appl.
No.: |
05/320,553 |
Filed: |
January 2, 1973 |
Current U.S.
Class: |
248/553; 70/232;
400/691; 248/678 |
Current CPC
Class: |
E05B
73/0082 (20130101); Y10T 70/5867 (20150401) |
Current International
Class: |
E05B
73/00 (20060101); F16b 041/00 (); E05b
073/00 () |
Field of
Search: |
;248/203,19,25,23
;70/58,181,232,371 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Foss; J. Franklin
Attorney, Agent or Firm: Mon; Donald D. Angus; D. Gordon
Claims
What is claimed is:
1. An equipment mounting security device comprising an adhesive pad
adapted to be adhered to a mounting surface, a cover assembly
adapted to cover the adhesive pad so that said pad is essentially
exposed only to said mounting surface and the underside of said
cover, means within the cover lockably attaching the cover assembly
to the pad, means for attaching an equipment to the outside of said
cover from a position within the cover between the cover and the
pad and accessible only when said cover assembly is unlocked and
separated from the pad, said adhesive pad when adhered to a
mounting surface requiring many times the amount of force in
tension or shear to separate the pad from the surface than the
amount of force required to separate the pad from the surface by
peeling the pad from the surface.
2. An equipment security device comprising: a pad having a top
surface and a bottom surface; an adhesive layer attached to said
bottom surface for adhering said pad to a mounting base; first
fastening means secured to said top surface; a cover plate having
an upper surface and a lower surface, adapted to cover said pad;
equipment attaching means for attaching to said upper surface an
equipment to be protected, said equipment attaching means being
detachable from the equipment only from said lower surface; second
fastening means secured to said lower surface; engaging means
holding said first fastening means and said second fastening means
together so that the cover cannot be removed from the pad; and lock
means positioned at the cover plate to prevent disengagement of the
engaging means when the lock means is locked, said adhesive layer
being characterized by requiring, when adhered to such mounting
base, many times the amount of force in tension and in shear to
separate the pad from the base than the amount of force required to
separate the pad from the base by peeling the pad from the
base.
3. A device according to claim 2 in which the first fastening means
comprises a loop means and the attaching means comprises a passage
means which registers with the loop means when the cover plate
covers said pad and the engaging means is a device which engages
said loop means and said passage means.
4. A device according to claim 3 in which the engaging means
comprises a pin means and the loop means comprises a first
passageway means and the passage means comprises a second
passageway means which registers with the first passageway means
when the cover plate covers the pad, the pin being dimensioned to
fit through said first and second passageway means.
5. A device according to claim 4 in which each passageway means
comprises a plurality of passageways spaced apart and the pin means
comprises as many pins as the number of passageways of the pad.
6. A device according to claim 2 in which the adhesive is heat
sensitive.
7. A device according to claim 2 in which the adhesive is heat
sensitive and pressure sensitive.
8. A device according to claim 2 in which said first fastening
means comprises a plate secured to said top surface by adhesive
having characteristics similar to the adhesive layer attached at
said bottom surface of the pad and the loop means comprises loops
rising from said plate means.
9. An equipment security device comprising a pad having a top
surface and a bottom surface; a layer of adhesive material attached
to said bottom surface for adhering said pad to a mounting base; a
second layer of adhesive material attached to said top surface;
plate means adhered to said second adhesive layer, said plate means
being provided with a plurality of members raised above the surface
of the plate means, providing a plurality of aligned openings; a
cover plate having an upper surface and a lower surface adapted to
cover said pad and plate means; equipment-attaching means for
attaching to said upper surface an equipment to be protected, said
equipment-attaching means being detachable from the equipment only
from said lower surface; lug means depending from said lower
surface, said lug means containing a plurality of aligned holes
adapted to align with said openings of the plate means; pin means
adapted to pass through said aligned openings and aligned holes to
prevent removal of said cover from the pad; and lock means
positioned at a part of the cover plate to prevent disengagement of
the pin means from the openings and holes when the lock means is
locked; said adhesive layers being characterized by requiring, when
adhered to said mounting base and to said plate means, many times
the amount of force in tension and in shear to separate the pad
from the base and the plate means from the pad, than the amount of
force required to make the separation by peeling the pad from the
base.
10. A device according to claim 9 in which the plate means
comprises a first pair of plates spaced from each other with
openings in alignment and a second pair of plates spaced from each
other with openings in alignment, the axes through the openings of
said second pair being parallel to the axes of the openings through
said first pair, and said lug means comprises a first pair of
spaced lugs positioned to locate their holes adjacent the
respective openings of the first pair of plates and a second pair
of spaced lugs positioned to locate their holes adjacent the
respective openings of said second pair of plates; and the pin
means comprises a first pin adapted to pass through the openings
and holes of the first pair of plates and first pair of lugs and a
second pin adapted to pass through the openings and holes of the
second pair of plates and second pair of lugs; and the lock means
comprises an individual lock for each pin, whereby each lock can
maintain its respective pin in position through the openings and
holes of its respective plates and lugs.
Description
SPECIFICATION
This invention relates to security devices for fastening equipment
such as office equipment, for example typewriters, adding machines
and computers and other more or less similar equipment such as
microscopes, televisions, projectors, safes and the like, to their
mounting surfaces; and more particularly to such security devices
which are lockably attached to the mounting surface.
It has long been a problem within business and other organizations
and buildings to avoid loss or misplacement of relatively small
costly items of equipment such as typewriters and other business
machines and the like due to unauthorized moving of such equipmnet
from place to place, and to thievery and burglaries. Various
expedients have been used to reduce such unauthorized movement or
loss of such equipment. One such expedient has been that of bolting
and bolt-locking or cable or chain locking of the equipment to the
surface to which it is mounted. A common method of doing this has
been to drill holes through the mounting surface and bolt through
the surface into the equipment to be secured thereto. One of the
more sophisticated bolting methods has been to place a locked cover
over the bolt or stud and nut so that they cannot be easily
removed. But bolting typewriters and desk calculators and the like
to desk tops has frequently made the drawers and writing leaves
directly beneath the piece of equipment thus bolted, unuseable due
to interference of the bolting device and the drawer or sliding
writing leaf. Furthermore, damage to clothes and persons have
sometimes resulted from such a bolting device on a typewriter or
the like snagging stockings and causing abrasions and cuts on the
person. Cabling and chaining also requires bolting the chain or
cable to a mounting surface and to the equipment.
Other disadvantages of the use of bolts, chains and cables are
obvious. Furniture, tables, desks or counters which have had holes
drilled in them for use with one model or type of equipment must
have additional holes in different locations drilled to accommodate
a new or different model or type of equipment. Furthermore, when
bolted-down equipment is permanently removed there remain holes in
the desk, counter, table or bench, all of which has been a
deterrent to the use of bolts for security purposes.
It is also apparent that to achieve successful bolting down of
equipment to a piece of furniture, the frame or case of the
equipment must be thick and strong enough to be threaded so that a
bolt or stud may be threaded into it, and the frame or plastic of
the equipment must be capable of taking a concentration load at the
bolt-down positions so that the equipment and bolts can
successfully resist attempts to move the equipment. Most plastic
cased equipment does not have plastic covers or frames thick enough
to distribute the concentrated loads presented by a bolting device
during an unauthorized attempt to move the equipment, as for
example during a burglary.
Bolting devices also have other drawbacks. One of these is that
they frequently make installation difficult and time consuming
under such circumstances as when the underside of the mounting
surface is not easily accessible because of drawers or frame
members in a desk, cabinet, bench or table or the like. Also,
inaccessible bolts and nuts make removal of the equipment for
periodic maintenance and repair, a time consuming job, frequently
interrupting the normal work of persons who would use the
equipment.
It is accordingly an object of the present invention to overcome or
avoid the foregoing disadvantages of prior known expedients for
securing equipment to their mountings.
A related object is to provide a security device which does not
mark or deface commonly used surfaces upon which such equipment is
mounted, for example, formica, hardwoods, metal and other hard
surfaces.
Another object is to provide such a security device which can be
installed and removed by working at only one side of the mounting
surface.
Another object is to provide a device which does not require the
making of holes in the mounting surface.
Another object is to provide such a security device having a
portion which is temporarily but securely adhered to the mounting
surface and which need not be removed from the mounting surface
when the equipment is unlocked and removed for service or
replacement.
Another object is to provide such a security device having a
portion temporarily but securely adhered to the mounting surface
which can be removed without damage to most mounting surfaces.
A further object is to provide such a device having means
preventing access to the member adhered to the mounting
surface.
A further object is to provide for fastening the equipment by bolts
or the like in such a manner that when the security device is
locked the bolts fastening the equipment are not accessible.
Another object is to provide such a security device which can be
unlocked from the mounting surface for service or for transfer
elsewhere without requiring the removal of mounting bolts to the
mounting surface.
A further object is to provide such a security device which is
capable of securing relatively weak framed or cased equipment and
the like.
The foregoing objects are carried out according to the present
invention by use of an adhesive pad bondably adherable to a
mounting surface and lockably attached to a cover assembly which
covers the adhesive pad so that the pad is essentially exposed only
to the mounting surface and the inside of the cover, and is
inaccessible from outside the cover. Provision is made for
fastening the cover to the pad, inside the cover and locking means
is provided for preventing access to the fastening means until the
locking means is unlocked.
A feature of the invention resides in the use of an adhesive pad
which is relatively easily peelable from the mounting surface when
access is had to the pad by removal of the cover. A further feature
resides in the use of an adhesive which though permitting
relatively easy peeling requires much more force to separate the
pad from the mounting surface by applying tension or shear than the
force required for peeling.
A preferred type of adhesive is one which is pressure or both
pressure and heat sensitive, that is, the application of pressure
even though fairly moderate, causes a bonding to the mounting
surface which requires very great force in tension or shear to
cause a separation from the mounting surface, but which when heated
after adherence to the mounting surface, permits peeling off the
mounting surface with relative ease. When the cover is locked in
position over the pad however, access is not had to the pad to
permit either heating or peeling of the pad.
The foregoing and other features of the invention will be better
understood from the following detailed description and the
accompanying drawings, describing and illustrating a specific
embodiment of the invention. In the drawings:
FIG. 1 is an isometric view, from the top, of a cover of a security
device according to this invention, shown mounted on a mounting
surface;
FIG. 2 is an isometric view of a pad assembly mounted on the
mounting base and attached beneath the cover of FIG. 1 according to
this invention, and therefore concealed from view in FIG. 1;
FIG. 3 is an isometric view looking upward at the bottom of the
cover shown in FIG. 1;
FIG. 4 illustrates one of two lock pins shown in FIGS. 6 and 7
which hold the cover to the pad assembly;
FIG. 5 illustrates one of two locks shown in FIG. 1, which prevent
removal of the lock pins shown in FIG. 3;
FIG. 6 is a cross-section view taken at line 6--6 of FIG. 1 showing
in phantom the outline of an equipment such as a typewriter
fastened to the cover shown in FIG. 1;
FIG. 7 is a cross-section view at line 7--7 of FIG. 1 illustrating
the relationship of a lock according to FIG. 5 to a lock pin
according to FIG. 4 and showing the lock key in phantom;
FIG. 8 is a cross-section view taken at line 8--8 of FIG. 7;
FIG. 9 is a detail view in cross-section showing an arrangement by
which an equipment like that shown in phantom in FIG. 6 can be
attached to the cover; and
FIG. 10 is a detail view in cross-section of an alternate form of
attachment of an equipment which may be used instead of that in
FIG. 9.
Referring to the drawings there is shown a security device 10
(shown in FIGS. 1, 6 and 7) according to this invention, comprising
a rectangular shaped cover 11 placed over a retangular shaped pad
12 (best shown in FIG. 2) mounted on a mounting support 13 which
may be, for example, the top of a table or desk or the like. The
pad 12 contains a suitable material 14, preferably one which is
pliable, a foam material for example a plastic foam. Where foam
material is used an open cell foam is preferred to a closed cell
foam. The top and bottom surfaces of material 14 are coated with
layers 15 and 16 of permanent adhesive material.
There are adhered to the upper surface of pad 12 by means of the
adhesive layer 16, four plates 17a, 17b, 17c and 17d, herein
referred to collectively as plates 17. The plates 17 are preferably
of a rigid material such as metal. Over the respective four plates
17 there are attached plates collectively referred to as 18 and
numbered 18a, 18b, 18c and 18d respectively which are attached to
their respective plates 17 by suitable means such as spot welding.
Each of the four plates 18 is formed with a pair of spaced
collinear loops 19 and the loops of plate 18b are collinear with
the loops of plate 18a. Likewise the loops of plates 18c and 18d
are all aligned in a collinear arrangement parallel with, but
spaced from, the loops of loop plates 18a and 18b. Each pair of
plates 17 and 18 is provided with aligned central openings 20 and
21 which expose the surface of pad 12. These openings are for the
purpose of permitting the application of the cover to the pad as
will appear hereinafter.
After completing this assembly of the plates on pad 12 the entire
upper surface of pad 12 is preferably covered with a coating of
paint or the like which will cover the adhesive layer 16 so that it
will not be sticky or tacky, and this paint coating is preferably
made to cover the exposed portions of plates 17 and 18. Until the
device 10 is put to use the bottom of adhesive layer 15 of pad 12
will be covered with a non-sticky protective layer of a fabric or
material (not shown) of a type commonly used to keep an adhesive
layer covered until used. When the device is ready to be used this
protective layer will be peeled off from the adhesive layer 15 so
that the pad may be made to adhere to its mounting base 13 by
laying the pad on the base and applying pressure.
The cover 11 (best seen in FIGS. 1, 3 and 6) has four sides 22a,
22b, 22c and 22d which closely fit down over the periphery of pad
12 and substantially meet the mounting base 13. One of the end
walls 22a is provided with a pair of holes or openings 23a and 23b.
The dimensions of the holes are such as to accommodate a
cylindrical type lock 24 (FIG. 5) as well as to permit the passage
of a lock pin 25 (FIGS. 4 and 7). The holes or opening 23a is
aligned with holes 26 and 27 through respective ones of a pair of
lugs 28 and 29 attached to and depending from the bottom surface of
cover 11, as shown in FIG. 3. The holes 26 and 27 are of a diameter
which accommodates one of the lock pins 25. The lugs 28 and 29 are
conveniently formed by depressing portions of the cover 11 as shown
at 28a and 29a in FIG. 1 so that part of each hole 26 and 27 is
formed from the depressed portion while the remaining part of the
hole is formed by a groove 30 formed at the bottom surface of cover
11 and aligned with holes 26 and 27 and with opening 23a. A similar
arrangement of depressed lugs and a groove are related to the notch
or opening 23b so that another lock rod 25 may be inserted through
opening 23b and through the holes of the lugs. Since the two
grooves are parallel, the two rods to be inserted will likewise be
parallel.
Before fitting the cover over the pad the equipment to be protected
by the device will be attached at the top of the cover. For this
purpose the cover is provided with four holes 31, preferably near
the corners through which attaching screws or bolts may pass. The
screw or bolt heads 33 will be placed at the under surface of the
cover and the threaded portions of such screws or bolts will pass
upwardly to thread into suitable tapped holes at a bottom surface
of the equipment, usually through suitable resilient washers or the
like 32 which may be of neoprene or the like.
With the equipment thus attached to the cover, the cover is brought
down over the pad as shown in FIGS. 1 and 6 with the four depressed
lugs 28 protruding into respective holes 20, 21 at the pad, such
that holes 26 at the cover are aligned with the openings through
respective loops 19 at the pad, and also with respective notches
23a or 23b of the cover. The pins 25 are then inserted through the
respective holes 23a or 23b and through the related openings 19, 26
and 27 so that the cover is now fastened to the pad by the two pins
25. The length of the pins 25 are such that when their forward ends
meet the wall 22c of the cover the rear of each pin is at a
sufficient distance inside wall 22a of the cover to accommodate
lock 24.
For the purpose of accommodating locks 24 there are provided
cylindrical lock housings 34 which form the respective openings 23a
and 23b. The housings 34 (FIGS. 7 and 8) are part of the casting
integral with wall 22a of the cover 11 and are at the under surface
of the cover. Also integral with the under surface of the cover is
a depending lug 35 having two horizontal bottom edges 36 and 36a
separated by a partially cylindrical surface 37 immediately inside
of the inner end of lock housing 34, which is concave as seen from
below. The partial cylindrical surface 37 is eccentric and of
smaller radius of curvature as compared with cylindrical housing
34.
The purpose of the cylindrical housing 34 and the lug 37 is to
accommodate the lock 24 and enable it to become locked and
unlocked, so that the corresponding lock pin 25 can be locked
within the cover or unlocked to permit extraction of the pin. To
lock the pin 25 in its lock-in position it is inserted through the
respective opening 23a or 23b and through the holes 26 and 27 and
loop 19 until the forward end of the pin substantially meets the
far side of the cover 22c. The lock 24 is then inserted through the
respective opening 23a or 23b formed by the cylindrical housing 34
which is dimensioned to fit the outer cylindrical barrel 39 of the
lock, with the key hole 40 of the lock toward the outside of the
cover. The lock is of the type having a rotary spindle 41 which is
cylindrical and concentric with the outer barrel 39 so that it can
rotate within the outer barrel. The spindle 41 is of substantially
the same length as the barrel 39 and its inner end terminates where
the inner end of the outer barrel terminates. At the inner end of
the spindle there is attached a cam 42 which is also cylindrical
but eccentric with the respect to the spindle 41. The diameter of
the cam cylinder 42 is such that it fits within the part-cylinder
37 of the lock housing. Thus when the lock 39 is fully inserted
within the housing the eccentric cylinder 42 engages part-cylinder
37, while the rear of the lock is flush with the outside of the
cover side 22a. Under this condition the lock barrel 39 cannot
rotate due to the eccentricity of member 42 so that the lock key 55
may rotate the lock spindle 41 without rotating the lock barrel 39.
There is attached at the inner side of eccentric cylinder 42
another cylinder 43 which is eccentric with respect to cylinder 42.
When the lock 24 is in its locked position as shown in FIGS. 7 and
8, the locking cylinder or disc 43 takes its position in which it
is partly in front of lug 37 so that the lock cannot be withdrawn
from its housing. When however the key is turned 180.degree. from
its position shown in FIG. 7 the part of the locking disc 43 which
is in front of lug 37 in FIG. 7 is now positioned downward so that
its lower portion is substantially even with the lower part of lock
spindle 41, in which position the lock may now be withdrawn from
its housing. This is the same position in which the lock must be
inserted into the housing. Upon removal of the lock, lock rods 25
may be removed from their position beneath the cover.
FIG. 9 shows an alternative manner of fastening an equipment to the
cover plate 11. This is useful where the equipment to be protected
has a strong or thick section 44. Here, the screw having screw head
33 passes through a rigid washer 45 and a resilient grommet 46 such
as neoprene attached to the cover 11 as shown, and then threads
into the thick section 44 of the equipment.
Where the equipment to be protected has a thin or weak section 47
for attachment, the arrangement of FIG. 10 may be used instead. In
this case, the screw having head 33 is passed through the cover 11
and threaded into a rigid plate 48 thereby holding the plate to the
cover. A resilient or rubbery ring 49 such as neoprene is adhered
as by layers 49a, 49b of cement or adhesive to the upper side of
the plate and the upper side of the ring 49 is similarly adhered by
adhesive to the section 47 of the equipment. The sandwich of ring
49 and its layers 49a and 49b of adhesive shown, have a tensile
strength at least as great as that of the attaching means 33 so it
is not the weakest link in the system. Hence, if there is a failure
in tension it is likely to be due to the stripping of threads of
fastener 33 in the member 11.
The adhesive used for layers 15 and 16 should be one that has a
long life and is slow to deteriorate and does not lose its ability
to bond tightly in pure tension or shear, but nevertheless always
remains peelable with the aid of heat and mild solvents and oil
combinations. Latex base adhesives are satifactory, and they may be
applied by spraying. Such adhesives are available from the Fasson
Division of Avery Adhesives, San Marino, Cal. under the trademark
"Fasmount" 2100; and from Minnesota Mining and Manufacturing
Company of Minneapolis, Minn. under the trademarks Scotch Brand
Tapes K-4408YEC4CDM3 as well as other companies under various
trademarks. All such adhesives are classified in the category of
pressure or thermal sensitive or both pressure and thermal
sensitive. Pressure sensitive as used herein means that by use of a
relatively small pressure it develops a bond which requires a great
deal more force in tension to break. Thermal sensitive means that
the application of heat loosens the bond. The adhesive 16 which
joins the loop 17 to the pad 12 may be the same as the adhesive 15
or alternatively it may be a permanent bonding adhesive so long as
its strength is of the same order or magnitude as adhesive 15,
although it need not necessarily be peelable.
The use and operation of the security device should be apparent
from the foregoing description. The pad 12 with the plate
combinations 17, 18 mounted on it as heretofore described, is
pressed down on the mounting surface 13 causing adhesive layer 15
to bond to the mounting surface. The equipment such as a
typewriter, calculator or the like, to be protected, is bolted to
the top of the cover 11 as described, and the cover is then set
down over the pad 12 and the locking pins 25 set in their
respective positions lying within grooves 30 of the cover, thereby
fastening the cover down so that its lower rim covers and surrounds
the pad and is in substantial contact with the mounting surface 13.
The locks 24 are then set in their respective positions within
openings 23a and 23b and locked so that the locking pins 25 cannot
be removed. Under this condition the equipment, such as the
typewriter or the like cannot be lifted by a person within a short
time, for it would require a lifting force of about 4,000 to 6,000
pounds to separate the bonds due to adhesive layers 15 and 16, at
least for a considerable period of time. While it may be true that
a long continued tensional lift might finally result in a
separation with less than 4,000 pounds tension the time required
for this to happen could easily lead to the apprehension of the
miscreant attempting the unauthorized transfer or taking of the
equipment.
When it is desired to remove the equipment for authorized transfer
or servicing the locks 24 are unlocked and withdrawn which uncovers
the rear ends of locking pins 25 permitting their withdrawal. To
facilitate the withdrawal of the locking pins the rear end of each
is provided with a tapped hole 50. Assuming the tapped hold has has
an unusual left hand thread it can be used for the withdrawal by
use of a pencil-like tool only having its forward end threaded with
an unusual left hand thread to enter hole 50 and thread to its
threads. Standard right handed threaded tools will not work in this
case. The term "unusual" as used herein means that a left hand and
a non-standard pitch is now difficult to find on the open market.
Such a non-standard pitch may be a left hand 10-18 or 10-26 thread.
The pencil-like tool is long enough to extend out through openings
23a or 23b while threaded to the lock pin. The locking pin is then
readily pulled out by pulling on the tool. The cover 11 can then be
readily lifted and the bolts or screws fastening the equipment can
be removed to permit transfer or servicing of the equipment.
If it be desired to transfer the entire security device as well as
the equipment this can readily be done after the cover is removed,
by peeling off the pad 12 from the mounting base 13. To perform
this peeling operation the plates 17a through 17d are first removed
from the top of the pad. To facilitate this removal, heat is
applied over the plates 17 and 18 by suitable heat lamps or the
like such as infra red heaters, thereby heating the material to a
temperature of about 150.degree. Fahrenheit at which temperature
the bonding force of the adhesive is greatly reduced so that these
plates can be removed from the pad. After removal of these plates
the heating unit is again applied over the pad to heat up the pad
material to 150.degree. Fahrenheit at which termperature the pad
can readily be peeled off the mounting base. The peeling is most
easily accomplished by starting the peeling operation at a corner
of the pad.
The use of rubbery or a foam-like material for the pad and in the
mountings, as described, promotes quietness of operation of
machines such as typewriters and calculators and the like which may
be mounted on the cover plate. It is furthermore desirable to fit a
rubber-like strip 56 to the lower rim of sides 22a, 22b, 22c and
22d of the cover 11. Although such strip is not illustrated in FIG.
3, it is shown in FIG. 6 as a strip containing a groove into which
the rim of the cover is fitted so that sides of the strip extend
upward for a short distance at the inside and outside of the rim
leaving a thickness of the rubbery material between the rim and the
mounting base 13. There are discontinuities in this strip at the
locations of the lock housings 34, the lower parts of which are
positioned slightly above the mounting base 13 when the cover with
the strip 56 is brought down against the mounting base.
Although only one specific embodiment of the invention has been
described and illustrated in the drawings it will be understood
that variations within the scope of the invention may readily
suggest themselves to those skilled in the art. For example, the
security device may be made in any of a number of different sizes
and shapes to suit particular items of equipment with which it is
to be used. Furthermore, modifications within the scope of the
invention may be made even in the embodiment which is herein
illustrated without departing from the scope of the invention which
is limited only by the scope of the appended claims.
* * * * *