U.S. patent number 3,744,282 [Application Number 05/198,908] was granted by the patent office on 1973-07-10 for office equipment locking device.
This patent grant is currently assigned to Sekur-It Products, Inc.. Invention is credited to Robert W. Hemphill.
United States Patent |
3,744,282 |
Hemphill |
July 10, 1973 |
OFFICE EQUIPMENT LOCKING DEVICE
Abstract
A locking device for portable equipment, such as typewriters,
adding machines, television sets, etc., comprises a rectangular
metal plate adapted to be fastened to the underside of said
equipment in substantially completely covering relation to said
underside e.g., adjacent the supporting legs thereof. At least one
elongated shaft extends at right angles to and below the plate for
insertion through a pre-drilled hole in a supporting surface for
the piece of equipment. A key-operated lock member engages the
shaft below the supporting surface to lock the piece of office
equipment to the supporting surface.
Inventors: |
Hemphill; Robert W. (Kendall
Park, NJ) |
Assignee: |
Sekur-It Products, Inc.
(Newark, NJ)
|
Family
ID: |
22735390 |
Appl.
No.: |
05/198,908 |
Filed: |
November 15, 1971 |
Current U.S.
Class: |
70/58;
70/232 |
Current CPC
Class: |
E05B
73/0082 (20130101); Y10T 70/5867 (20150401); Y10T
70/5009 (20150401) |
Current International
Class: |
E05B
73/00 (20060101); E05b 073/00 () |
Field of
Search: |
;70/57,58,62,232
;248/25,203,361 ;312/215 ;211/4 ;85/9R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wolfe; Robert L.
Claims
Having thus described my invention, I claim:
1. A locking device for use with office equipment of the type
having a substantially rectangular base provided with leg members
at the four corners of said base normally adapted to support said
equipment on a supporting surface, said locking device comprising a
rectangular metallic plate having a substantially uninterrupted
surface configuration dimensioned to substantially equal the
dimensions of the rectangular base of said office equipment, said
rectangular plate being provided with four countersunk round holes
at its four corners adapted to receive bolts for thread engagement
with said base at locations adjacent said leg members respectively
whereby said plate may be integrated with the base of said office
equipment in closely adjacent substantially completely covering
relation to said base, an elongated shaft attached to said plate
and extending in a direction transverse to the plane of said plate,
said shaft being adapted for insertion through a pre-drilled hole
in the supporting surface for the piece of office equipment, and a
removable key-operated lock member adapted to engage with and lock
to that portion of said shaft which extends through and beyond the
underside of said supporting surface to lock said piece of office
equipment to said supporting surface.
2. The device of claim 1 wherein said shaft includes a threaded
portion, said lock member comprising a nut threadengaging said
threaded portion of said shaft, and a shield structure covering
said nut to render it manually inaccessible.
3. The device of claim 1 wherein said plate includes a centrally
located round aperture, said shaft being removably insertable from
the upper side of said plate through said aperture and including a
head engaging a portion of said plate adjacent the upper surface of
said plate to limit downward movement of said shaft relative to
said plate.
4. The device of claim 3 wherein said aperture comprises a
countersunk hole having inclined sides, said head being of conical
configuration for engagement with said inclined sides.
5. The device of claim 1 wherein said four round holes in said
plate are dimensionally and positionally spaced from one another
precisely in accordance with the dimensional and positional spacing
between the supporting legs of said piece of office equipment,
whereby said plate can be attached to the underside of said piece
of office equipment by removing said supporting legs from said
piece of equipment and then reattaching said supporting legs to
said piece of equipment via said apertures.
Description
BACKGROUND OF THE INVENTION
In recent years, incidents of theft and burglary have risen at an
alarming rate. The problem has become especially serious in
business offices due to the fact that modern office equipment, e.g.
typewriters, adding machines, calculators, etc., have become
lighter in weight, smaller in size, and much more costly in price;
and since most business offices are unstaffed after business hours,
the unauthorized removal of office equipment has become quite
prevalent. This has necessarily resulted in major losses to
business establishments, and has also produced significant
increases in insurance rates.
Various suggestions have been made heretofore of devices adapted to
safeguard highly vulnerable office equipment from unauthorized
removal or theft. However, for the most part, the arrangements
which have been suggested thus far have not experienced any
significant commercial acceptance since they have tended to be
complex in construction, costly, unsightly, and difficult to
install and remove.
By way of example, prior suggestions for safeguarding office
equipment are described in Buchman U.S. Pat. nos. 2,434,312 and
3,514,172. The Buchman arrangements are adapted to lock a
typewriter, or the like, to a table or desk; and the arrangements
suggested include a housing which is designed to be disposed below
the table, and which cooperates with a pair of bolts extending from
said housing through the table. One of the bolts is fastened
directly to the table on its upper side, and the other bolt is
threaded into a bolt hole in the bottom of the typewriter. A lock
extends through the housing on the underside of the table, and the
lock is so positioned that it inhibits access to the heads of the
aforementioned bolts. While this structure is capable of
safeguarding the equipment in question, it typifies the
difficulties discussed earlier, i.e. it is a comparatively large,
costly, and complex piece of equipment, is difficult to install or
remove requiring substantial time for either operation, and is
clearly visible when installed thereby making for an unsightly
installation.
A similar arrangement is disclosed in Bennett U. S. Pat. No.
3,564,879. The Bennett device again provides a housing below the
table with the housing being adapted to conceal the heads of a pair
of screws which extend from the housing through the table into
thread engagement with the underside of a business machine. A lock
is inserted into the housing to prevent access to the screw heads.
The Bennett device suffers from the various disadvantages already
described in reference to the Buchman devices.
The present invention, recongizing the disadvantages of the prior
art, is concerned with a highly improved, completely reliable,
locking device of extremely simple and inexpensive construction,
adapted to lock a piece of office equipment to a supporting
surface. As will be apparent, the device is capable of use on
various different types of portable equipment, including those used
in offices (e.g., typewriters) and in the home (e.g. television
sets); and the term "office equipment" used herein, and in the
appended claims, is intended to be generic to all such portable
equipment.
The device of the present invention is capable of rapid
installation on a piece of office equipment to be protected, and
provides substantially fool-proof protection when installed. The
device, moreover, lends itself to ready removal from a piece of old
equipment when it is desired to transfer the locking device to a
piece of replacement equipment. When installed, the device is, for
all practical purposes, invisible; and this feature not only
enhances the decor of a home or office employing the locking
device, but also makes the device far less vulnerable to tampering
or attempts at unauthorized removal.
SUMMARY OF THE INVENTION
In accordance with the present invention a locking device is
provided which comprises a rectangular, substantially
uninterrupted, planar steel plate having an array of apertures
therein for attaching said plate to the underside or base of a
piece of office equipment, e.g., through the agency of bolt or
screw holes pre-existing in said underside or in the superstructure
of the machine or equipment to be locked in place. In accordance
with an alternative embodiment of the invention, for use in those
cases where the equipment is not provided with pre-existing bolt
holes in its underside, the apertures in said plate can be
dimensionally and positionally spaced from one another in
accordance with the dimensional and positional spacing between the
supporting legs of the piece of equipment to be protected; and in
this embodiment of the invention, the plate is attached to said
piece of equipment by unscrewing the legs screws provided by the
machine manufacturer (e.g., to hold leg cushions or rubber scratch
guards in place) whereafter the plate is placed substantially flush
with the bottom of the equipment and fixedly attached thereto by
inserting the leg screws back in place via the apertures in said
plate.
When the plate is installed in either of these fashions, i.e.,
directly to the base of the equipment or, alternatively, via the
leg screws of the equipment, the plate is integrated with the base,
substantially completely covers the base, and is substantially
invisible to the eye; and, in addition, when the equipment is then
placed on a supporting surface the screws or bolts holding the
plate in place become totally inaccessible.
The steel plate is provided with an elongated shaft which extends
in a transverse direction, preferably at substantially right
angles, to and below the plate. This shaft is adapted to be
inserted through a pre-drilled hole in the equipment supporting
surface so that, when the plate and its associated shaft is
attached to the underside of the piece of equipment and said
equipment is then placed on a supporting surface with the shaft
inserted through said pre-drilled hole, a portion of said shaft
extends below the supporting surface. This latter portion of the
shaft is associated with a key-operated locking member adapted to
engage said shaft and the underside of said supporting surface to
hold the shaft, plate, and equipment in fixed position on said
supporting surface.
More than one such shaft can be employed, e.g. two shafts extending
in parallel relation to one another, and at right angles to and
below the plate, can be provided for insertion through a pair of
predrilled holes in the equipment supporting surface, with the
lowermost ends of that pair of shafts being associated in turn with
a lock member having a pair of bores extending therethrough for
slidable insertion onto the shafts. Locks of this type are
available from various manufacturers under generic designations
such as "through-shackle", "barrel", or "bicycle" locks. A parallel
shaft arrangement of this type requires, however, the pre-drilling
of a pair of accurately spaced holes in the supporting surface;
and, accordingly, the preferred embodiment of the present invention
utilizes a single shaft associated with a locking member. A
plurality of such single shafts, extending at right angles to the
aforementioned plate, could, of course, be provided; but again,
this requires the drilling of a plurality of accurately spaced
holes in the supporting surface. Since it has been found in
practice that reliable locking is achieved by use of only one
shaft, this represents the preferred embodiment of the present
invention.
The aforementioned shaft can be fixedly attached to the plate, at
right angles thereto, by techniques such as welding. When the shaft
is permanently attached to the plate by such a technique, however,
the weld joint represents a point of possible vulnerability since
the joint can sometimes be broken by a screw driver or crowbar.
Moreover, when the shaft is permanently attached to the plate, the
overall locking device becomes rather bulky making it difficult to
package the locking device for transportation and sale. For these
reasons, therefore, the shaft structure, in the preferred
embodiment of the present invention, comprises an elongated shaft
removably insertable through a complementary aperture in said
plate, and provide with an enlarged head adapted to engage the
upper side of said plate when the shaft is inserted in place. With
this arrangement, the shaft can be shipped in separated relation to
the plate for attachment to said plate when the overall locking
device is later installed; and, when installed in place, the shaft
then becomes completely invulnerable to tampering by a screw driver
or crowbar.
If the equipment being protected is motor driven, the
aforementioned plate can be provided with one or more vent holes
disposed adjacent the driving motor of the equipment to facilitate
ventilation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a locking device constructed in accordance with
the present invention, as installed on a piece of portable
equipment;
FIG. 2 is a perspective view of the locking device;
FIG. 3 is a plan view of the structure shown in FIG. 2;
FIG. 4 is a view taken on line 4--4 of FIG. 3 illustrating the
details of the shaft and associated lock member; and
FIG. 5 is a detail view illustrating one technique for attaching
the locking device to a piece of equipment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the several figures, like numerals of which refer to
like parts throughout, it will be seen that a locking device
constructed in accordance with the present invention comprises a
plate 10 preferably constructed of metal, e.g. steel, and having a
thickness in the order of one-eighth inch. The plate 10 is
preferably rectangular and is provided with an array of countersunk
apertures 11 which, in the particular embodiment illustrated,
comprises four such apertures 11 disposed adjacent the corners
respectively of the rectangularly shaped plate 10.
The actual positions and numbers of apertures 11 may vary from one
installation to another in dependence upon the office equipment
which is to be locked in place, and the nature of the bolt or screw
holes which are present in the underside of said equipment. More
particularly, the office equipment 12 customarily includes a
superstructure 13 which, in some cases, is provided with a
plurality of pretapped bolt or screw holes which are intended, by
the equipment manufacturer, to be utilized either to secure the
equipment to a supporting surface, or to receive auxiliary members
for leveling or steadying the equipment. When such pretapped bolt
or screw holes already exist in the equipment, the plate 10 is
dimensioned to fit between the supporting legs of the equipment;
and the apertures 11 are positioned and spaced in accordance with
the existing pretapped bolt holes in the equipment so that said
plate can be attached to the underside or superstructure 13 of the
equipment by means of appropriate bolts or screws inserted through
apertures 11.
In those cases where the superstructure 13 of the equipment 12 is
not provided with pretapped holes, and it is not convenient or
desirable to add such holes to the equipment for use in stalling
the locking device of the present invention, the various apertures
11 are dimensioned and positionally spaced from one another in
accordance with the dimensional and positional spacing between the
supporting legs of the equipment. More particularly, as best
illustrated in FIG. 5, the equipment 12 may be provided with leg
structures comprising leg members 16 having leg cushions 17
attached thereto by means of a bolt or screw member 18 (the term
"legs" used herein being intended to refer to the supporting legs
themselves, or to the supporting cushions for said legs, or to
other supports or steadying structures provided, as the case may
be, for supporting and/or steadying the piece of equipment 12 on
the supporting surface 19 such as a table, desk or the like). The
plate 10 may, in such case, be installed on the equipment 12 by
first unscrewing the leg screws 18 provided by the machine
manufacturer, then placing the plate 10 against the underside of
the equipment with its several apertures 11 positioned adjacent the
legs 16, and finally reinserting the leg screws 18 in place. By
this procedure, the plate is again firmly attached to the underside
of the equipment through the agency of the pre-existing leg screws
of that equipment; and when the equipment is thereafter placed on
the supporting surface 19, the leg screws become totally
inaccessible and invulnerable to tampering.
While it is contemplated that the plate 10 and its associated
apertures 11 are preferably shaped and dimensioned to permit
installation of the locking device on a predetermined specific type
(manufacturer and/or model) of office equipment, some universality
may be achieved, permitting a given plate to be installed on
various different types of office equipment (having various
different spacings between its underside bolt holes, or between its
supporting legs, within a predetermined range of spacings) by using
"universal" apertures. One possible such universal aperture is
designated, in broken line, at 11a in FIG. 3, and comprises an
aperture of slotted configuration in place of a round aperture.
Such a slotted configuration, or other configurations serving
similar purposes, could be employed at selected one or all of the
aperture 11 positions.
Plate 10 is provided with a countersunk hole 14 located at a
generally central position in said plate. Hole 14 is adapted to
receive an elongated shaft comprising, in a preferred embodiment of
the invention, a one-half inch diameter flathead cap screw 20
having a conical head 20a and a threaded shaft 20b (see FIG. 4).
The sides of head 20a are complementary to hole 14 so that when the
bolt comprising shaft 20 is inserted through hole 14 from its upper
side, the shaft extends below plate 10 at substantially right
angles thereto and is limited in downward movement, and retained in
place, by the abutment between the sides of head 20a and hole
14.
It will be appreciated, of course, that other arrangements serving
a similar purpose could be provided, e.g., the hole 14 could be
cylindrical, and the head 20a could be of enlarged configuration
adapted to engage the upper side of plate 10. In either event, the
bolt or shaft 20 is separable from plate 10 to facilitate packaging
and shipping of the locking device. When bolt 20 is inserted
through the upperside of plate 10, and the locking device
thereafter is installed in place, the head which retains the shaft
in place becomes completely concealed and inaccessible.
In practice, supporting surface 19 is provided with a predrilled
hole 21 adapted to receive shaft 20. The shaft 20 is first inserted
through hole 14 in plate 10 from its upper side, whereafter plate
10 is attached to the underside of equipment 12 in one of the
fashions already described. The assembly is then placed on
supporting surface 19 with shaft 20 extending through the
aforementioned predrilled hole 21; and the length of shaft 20 is so
chosen that, at this time, approximately three-fourths inch of the
threaded portion 20b extends below the lower side of supporting
surface 19. This lowermost portion of the shaft 20 receives a key
operated locking member, generally designated 22 in FIG. 1.
The details of the key-operated lock member 22 are best shown in
FIG. 4. The lock structure is commercially available from On Guard
Corp. of America, of Carlstadt, N.J., and is presently sold by that
company as a "wheel lock" for automobiles. The particular structure
shown in FIG. 4 corresponds to Model No. 3-18 of said "wheel lock",
and comprises a combination nut and lock housing 23, a lock housing
shield 24, and a lock cylinder 25 operated under the control of a
key 26. These various parts are separable from one another, but can
be assembled to provide the desired locking structure.
More particularly, after the assembly is placed on supporting
surface 19 with a portion of shaft 20 extending therethrough, a
steel washer 27 is first placed over shaft 20 adjacent the
underside of surface 19. The upper end (as shown in FIG. 4) of
structure 23 comprises a lock nut and is provided with a plurality
of interior threads 23a which mate with the threads on portion 20b
of shaft 20. Structure 23 is threaded onto shaft portion 20b and
turned down to a position in engagement with washer 27 closely
adjacent the underside of surface 19. At this time, the lower (lock
housing) end of structure 23 extends below the lowermost end of
shaft 20; and this lower end is provided with a plurality of
interior grooves 23b which are adapted to selectively receive
outwardly extending locking bars 25a forming a portion of the
locking cylinder 25.
When element 23 has been turned down completely, the lock housing
shield 24 is placed over element 23, in freely spaced relation
thereto, with its upper end in engagement with washer 27. Lock
cylinder 25 is then inserted through the lowermost end of shield 24
with collar 25b of said cylinder 25 in abutment with an interior
shoulder 24a of shield 24; and cylinder 25 is inserted into the
lower, lock housing, end of structure 23 so that its locking bars
25a engage the grooves 23b to retain the structure in assembled
configuration. At this time, shield 24 is freely rotatable relative
to both structure 23 and cylinder 25, and completely encloses
element 23 to prevent its removal from the threaded portion 20b of
shaft 20.
Lock cylinder 25 is so constructed that insertion of the key 26
causes locking bars 25a to retract, while removal of key 26 causes
said locking bars 25a to automatically extend in an outward
direction. The lock can accordingly be removed simply by inserting
key 26 to retract locking bars 25a thereby permitting the entire
lock cylinder 25 to be removed. This in turn permits the rotatable
shield 24 also to be removed so as to provide access to lock nut
23.
In those cases where the office equipment to be protected is motor
driven, (e.g., if the piece of office equipment 12 comprises a
typewriter of the electric type) the plate 10 can be provided with
an edge recess or with one or more interior vent apertures 28,
located at that portion of plate 10 which is disposed adjacent the
equipment motor when the plate is installed in place, to facilitate
motor venilation.
While I have thus described preferred embodiments of the present
invention, many variations will be suggested to those skilled in
the art. For example, while the particular lock structure shown in
the drawings is actuated by a key member 26, other locks could be
employed which are of the combination lock type; and the term "key"
used herein, and in the appended claims, is intended to be generic
to this latter type of lock as well. Still other variations have
already been described. It must therefore be understood that the
foregoing description is intended to be illustrative only and not
limitative of the invention; and all such variations and
modifications as are in accord with the principles described are
meant to fall within the scope of the appended claims.
* * * * *