U.S. patent number 3,736,779 [Application Number 05/137,176] was granted by the patent office on 1973-06-05 for lock.
Invention is credited to Eugene L. Pratt.
United States Patent |
3,736,779 |
Pratt |
June 5, 1973 |
LOCK
Abstract
A lock is disclosed comprising an upper locking unit and a lower
locking unit, said upper locking unit comprising an opening, a
plunger disposed within said opening, said opening being so
dimensioned as to permit said plunger to be slidably displaced
within said opening, said plunger being of such a material that
said plunger is caused to be slidably displaced within said opening
by a magnetic force being placed in close proximity thereto, said
lower locking unit comprising an opening so dimensioned as to
receive said plunger, means retaining the upper portion of said
plunger in said upper locking unit when the lower portion of said
plunger is disposed in said opening of said lower locking unit
whereby said upper locking unit is locked to said lower locking
unit when said plunger is disposed within said openings in said
upper and lower locking units and whereby said upper locking unit
is unlocked from said lower locking unit when a magnetic force is
brought into close proximity with said plunger causing said lower
portion of said plunger to be removed from within said opening in
said lower locking unit.
Inventors: |
Pratt; Eugene L. (Philadelphia,
PA) |
Family
ID: |
22476138 |
Appl.
No.: |
05/137,176 |
Filed: |
April 26, 1971 |
Current U.S.
Class: |
70/276; 292/184;
292/340; 292/DIG.65; 292/251.5 |
Current CPC
Class: |
E05B
47/0038 (20130101); E05B 47/004 (20130101); Y10T
70/7057 (20150401); Y10S 292/65 (20130101); Y10T
292/11 (20150401); Y10T 292/1007 (20150401); Y10T
292/68 (20150401) |
Current International
Class: |
E05B
47/00 (20060101); E05b 047/00 () |
Field of
Search: |
;70/7,9,11,91,95,97,101,129,276
;292/144,148,183,184,300,302,327,DIG.32,DIG.65 ;16/147,176 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Craig, Jr.; Albert G.
Claims
I claim:
1. A lock comprising an upper locking unit and a lower locking
unit, said upper locking unit having a passage, a plunger disposed
within said passage, said passage being so dimensioned as to permit
said plunger to be slidably displaced within said passage, said
plunger being of such a material that said plunger is caused to be
slidably displaced within said passage by a magnetic force being
placed in close proximity thereto, said lower locking unit having a
passage so dimensioned as to receive said plunger, means retaining
the upper portion of said plunger in said upper locking unit when
the lower portion of said plunger is disposed in said passage of
said lower locking unit, an opaque plate which permits magnetic
lines of force to be transmitted therethrough covering said passage
of said upper locking unit having at least two perpendicularly
disposed contoured surfaces to permit said plunger to ride up onto
the upper surface of said lower locking unit so that said plunger
may be aligned with and drop to 2 position partially within said
passage in said lower locking unit, whereby said upper locking unit
is locked to said lower locking unit when said plunger is disposed
within said passages in said upper and lower locking units and
whereby said upper locking unit is unlocked from said lower locking
unit when a magnetic force is brought into close proximity with
said plunger causing said lower portion of said plunger to be
removed from within said passage in said lower locking unit.
2. A lock is accordance with claim 1 wherein said upper locking
unit includes means to attach said upper locking unit to a cabinet
door and wherein said lower locking unit includes means to attach
said lower locking unit to a cabinet door.
3. A lock in accordance with claim 2 wherein said plunger is
comprised of a head of a first diameter and a shaft of a second
diameter, said passage of said upper locking unit comprising a
first opening having a diameter slightly greater than said first
diameter, and a second opening having a diameter slightly greater
than said second diameter, said first opening leading into said
second opening, said head of said plunger being slidably disposed
within said first opening and said shaft of said plunger being
slidably disposed within said first and said second openings and
within said passage of said lower locking unit.
4. A lock in accordance with claim 1 wherein said upper locking
unit is attached to a first cabinet door, said lower locking unit
is attached to a second cabinet door, and said first and said
second cabinet doors open by pivoting about parallelly disposed
axes.
5. A lock in accordance with claim 1 wherein said upper locking
unit is attached to a first cabinet door, said lower locking unit
is attached to a second cabinet door, and said first and said
second cabinet doors open by sliding in parallelly disposed
paths.
6. A lock in accordance with claim 1 wherein said upper locking
unit is attached to a first cabinet door and said lower locking
unit is attached to the frame of the cabinet.
7. A lock in accordance with claim 1 further including a magnet
which when brought into close proximity with said plunger attracts
said plunder causing said plunger to be removed from within said
passage in said lower locking unit.
8. A locking in accordance with claim 7 further including a keeper
for said magnet, said keeper comprising a base to which said magnet
is attracted, a wall surrounding said base having a height less
than the height of said magnet, the inner periphery of said wall
having a length slightly greater than the outer periphery of said
magnet when disposed within said wall, the height and inner
periphery of said wall and the magnetic attraction between said
base and said magnet being such that the magnet may not be removed
from its keeper by twisting, sliding, or tilting of the magnet but
can only be removed by lifting said magnet in a direction
substantially perpendicular to said base.
9. A lock comprising an upper locking unit and a lower locking
unit, said upper locking unit having a passage, a plunger disposed
within said passage, said passage being so dimensioned as to permit
said plunger to be slidably displaced within said passage, said
plunger being of such a material that said plunger is caused to be
slidably displaced within said passage by a magnetic force being
placed in close proximity thereto, said lower locking unit having a
passage so dimensioned as to receive said plunger, means retaining
the upper portion of said plunger in said upper locking unit when
the lower portion of said plunger is disposed in said passage of
said lower locking unit, an opaque plate which permits magnetic
lines of force to be transmitted therethrough covering said passage
of said upper locking unit at the upper surface of said upper
locking unit, said lower locking unit having two oppositely
disposed contoured surfaces to permit said plunger to ride up onto
the upper surface of said lower locking unit during relative motion
between said upper and lower locking units so that said plunger may
be aligned with and drop to a position partially within said
passage in said lower locking unit, whereby said upper locking unit
is locked to said lower locking unit when said plunger is disposed
within said passages in said upper and lower locking units and
whereby said upper locking unit is unlocked from said lower locking
unit when a magnetic force is brought into close proximity with
said plunger causing said lower portion of said plunger to be
removed from within said passage in said lower locking unit.
10. A lock comprising an upper locking unit and a lower locking
unit, said upper locking unit having a passage, a plunger disposed
within said passage, said passage being so dimensioned as to permit
said plunger to be slidably displaced within said passage, said
plunger being of such a material that said plunger is caused to be
slidably displaced within said passage by a magnetic force being
placed in close proximity thereto, said lower locking unit having a
passage so dimensioned as to receive said plunger, means retaining
the upper portion of said plunger in said upper locking unit when
the lower portion of said plunger is disposed in said passage of
said lower locking unit, an opaque plate which permits magnetic
lines of force to be transmitted therethrough covering said passage
of said upper locking unit at the upper surface of said upper
locking unit, said lower locking unit having at least two contoured
surfaces disposed so as to permit said plunger to ride up onto the
upper surface of said lower locking unit irrespective of the
direction in which said upper locking unit is moved relative to
said lower locking unit so that said plunger may be aligned with
and drop to a position partially within said passage in said lower
locking unit, whereby said upper locking unit is locked to said
lower locking unit when said plunger is disposed within said
passages in said upper and lower locking units and whereby said
upper locking unit is unlocked from said lower locking unit when a
magnetic force is brought into close proximity with said plunger
causing said lower portion of said plunger to be removed from
within said passage in said lower locking unit.
11. A lock in accordance with claim 10, wherein said at least two
contoured surfaces includes a third contoured surface which permits
either of said upper and lower locking units to be moved to a
locking position followed by the other of said locking units into
said locking position without interference by the plunger.
Description
The present invention relates to a lock. More particularly, the
present invention relates to a lock that may be applied to cabinet
doors to prevent unauthorized entry, especially, unauthorized entry
by small children who may be damaged by the contents within the
cabinet.
The kitchen, the laundry room, the bathroom and other areas of the
home contain cabinets having house-hold items stored therein such
as detergents, pesticides, drugs, etc. Many of these items are
highly toxic, especially to small children. Since small children
are so curious and inquisitive, it is not uncommon for children to
obtain entry into these cabinets and to be harmed by the contents
therein.
This is not a small problem. For example, in the state of Illinois
in 1969, there were over 12,000 cases involving the accidental
poisoning of children. In fact, the Executive Director of the
Illinois Association for the Mentally Retarded has stated that
poisoning is one of the major causes of brain damage among children
under the age of 12.
To further illustrate, reports from the Philadelphia Department of
Public Health indicate that 5,000 children per year between the
crawling age and the age of 6 are hospitalized due to accidental
poisoning. The reports from the Philadelphia Department of Public
Health also indicate that the number of cases of accidental
poisoning is increasing.
Accordingly, it is the object of the present invention to provide a
lock to prohibit unauthorized entry into cabinets.
It is a further object of the present invention to provide a lock
which may be readily unlocked quickly and conveniently by
authorized personnel.
It is still another object of the present invention to provide a
lock whose external appearance gives no indication as to how the
lock may be opened.
It is yet a further object of the present invention to provide a
lock that may be internally mounted within a cabinet so that the
external appearance of the cabinet does not indicate that the
cabinet is locked, how it is locked, or how it may be opened.
It is another object of the present invention to provide a lock
with a self-locking feature so that the cabinet door or doors to be
locked may be locked by merely closing them.
Other objects will appear hereinafter.
In accordance with a first embodiment of the present invention,
upper and lower locking units are so disposed as to mate and lock
with each other. A slidable plunger is disposed within the upper
locking unit, and is completely hidden from view. Under the force
of gravity, the slidable plunger is displaced to enter an opening
in the lower locking unit thereby placing the locking units in
their locked position. The locking units may be unlocked by the
placement of a magnet in proximity with the plunger which is
magnetically attracted thereto causing the upward displacement of
the plunger thereby causing the lower portion of the plunger to be
lifted from within the opening in the lower locking unit.
In accordance with another embodiment of the present invention,
upper and lower locking units are mounted within a cabinet so that
the external appearance of the cabinet in its locked position
offers no indication as to whether it is locked, how it was locked,
or how it may be opened.
For the purpose of illustrating the invention, there are shown in
the drawings forms which are presently preferred, it being
understood, however, that the invention is not limited to the
precise arrangements and instrumentalities shown,
FIG. 1a illustrates the positional relationship between the upper
and lower locking units of a first embodiment of the present
invention.
FIG. 1b illustrates in greater detail the positional relationship
of FIG. 1a between the plunger of the upper locking unit and the
opening of the lower locking unit.
FIG. 2 is an exploded view of the upper and lower locking units of
a first embodiment of the present invention.
FIG. 3 illustrates how the locking units of FIG. 2 may be utilized
to lock a specific form of cabinet.
FIG. 4 illustrates how the locking units of FIG. 2 may be utilized
to lock another form of cabinet.
FIG. 5 illustrates a second embodiment of the present invention in
use with yet another form of cabinet.
FIG. 6 is a cross sectional view of a third embodiment of the
present invention as applied to still another form of cabinet.
FIG. 7 illustrates the third embodiment of the present invention as
applied to a further form of cabinet.
FIG. 8 is a cross sectional view taken along lines 8--8 of FIG.
7.
FIG. 9 illustrates a keeper in accordance with the present
invention for securing from children the magnet used for opening
the cabinet.
Referring to the drawings in particular, FIG. 1a illustrates the
disposition of upper locking unit 12 and lower lower locking unit
14 in their locked position. Lower locking unit 14 contains screws
16 and 18 which extend therethrough and allow lower locking unit 14
to be attached to a movable cabinet door or the like. Similarly,
upper locking unit 12 contains screws 20 and 22 which permit upper
locking unit 12 to be rigidly mounted to a movable cabinet door or
the like. Although screws have been disclosed as a means for
attachment, it is well within the realm of the present invention to
utilize other attachment means such as nails, adhesives, etc.
The topmost portion of upper locking unit 12 is covered by plate
36. Plate 36 may be any material that will readily permit magnetic
lines of force to pass therethrough. Immediately below plate 36 in
the left hand sector of upper locking unit 12 is a relatively large
diameter passage or opening 32 which, as shown in the drawing,
becomes a relatively smaller diameter passage or opening 34 in the
lower left sector of upper locking unit 12. Disposed within
openings 32 and 34 is a plunger 26 which is comprised of a head 30
and a shaft 28. Head 30 is constructed of a material that is
attracted by a magnet. Therefore, as shown in FIG. 1b, the placing
of a magnet over the top left sector of upper locking unit 12
causes head 30 and shaft 28 to be upwardly displaced in opening 32.
This also causes the upward displacement of shaft 28 within opening
34.
Lower locking unit 14 is so disposed with respect to upper locking
unit 12 that passage or opening 24 is disposed immediately below
opening 34. Therefore, it is clear that the downward displacement
of plunger 26 causes the entrance of shaft 28 into opening 24 of
lower locking unit 14. When plunger 26 is downwardly displaced by
the force of gravity, shaft 28 enters opening 24 thereby locking
upper locking unit 12 with respect to lower locking unit 14. The
upward displacement of plunger 26 by the placement of a magnet
thereabove causes shaft 28 to be removed from within opening 24
thereby unlocking lower locking unit 14 from upper locking unit
12.
It should be noted that the appearance of upper locking unit 12 and
lower locking unit 14 in their locked position does not indicate
how or in what manner the unlocking may be accomplished. Since
upper locking unit 12 and lower locking unit 14 are preferably of
opaque material and since plate 36 which covers head 30 is also
preferably of opaque material, the external appearance of the
locked units does not indicate if they are locked, how they were
locked, or how they might be unlocked.
FIG. 1b illustrates in greater detail the disposition of shaft 28
within opening 24. As shown in FIG. 1b, opening 32 is of such a
height that the upward displacement of head 30 and shaft 28 through
the action of magnet 44 causes shaft 28 to be entirely withdrawn
from opening 24. It is also noted that opening 32 is of a depth to
permit the entrance of shaft 28 into opening 24 when magnet 44 is
removed permitting head 30 and shaft 28 to be downwardly displaced
by the force of gravity.
FIG. 2 illustrates upper locking unit 12 and lower locking unit 14
in exploded view. FIG. 2 shows quite clearly how plate 36 covers
upper locking unit 12 and conceals from view head 30. Plate 36 may
be affixed to upper locking unit 12 by means of adhesive 42 as
shown in FIG. 2. However, it is well within the realm of the
present invention to utilize other attachment means such as nails,
screws, etc.
As shown in FIG. 2, lower locking unit 14 has contoured edges 38,
40 and 41. Contoured edge 41 (designated in the drawing but not
visible due to the angle of the illustration) is similar in shape
to contoured edge 40 and is disposed directly opposite thereto. The
purpose of these contoured surfaces is to permit lower locking unit
14 to be locked to upper locking unit 12 without the use of a
magnet by merely closing the cabinet doors to which locking units
12 and 14 are affixed. When upper locking unit 12 is separated from
lower locking unit 14, and head 30 is not upwardly displaced under
the force of a magnet, shaft 28 protrudes beyond the lower surface
of upper locking unit 12. However, by sliding upper locking unit 12
over either contoured surface 38, 40 or 41, shaft 28 is forced to
ride up onto the top surface of lower locking unit 14 and into
opening 24. Whether or not contoured surface 38, 40 or 41 is
utilized depends upon the manner in which the cabinet doors to
which the locking units are attached are hinged. However, it should
be noted that there is no necessity that lower locking unit 14
contain contoured surfaces 38, 40 and 41 as it is possible to lock
the units by merely using a magnet to cause the upward displacement
of head 30 until shaft 28 is disposed on the top surface of lower
locking unit 14 at which time the magnet may be removed. This may
be desirable if there is a requirement that the units not be locked
unless there is some assurance that the magnet is readily locatable
to unlock the units. Alternatively, it is possible to use one's
finger to raise shaft 28 until it is disposed on the top surface of
lower locking unit 14.
FIG. 3 illustrates a cabinet 46 that has affixed thereto the
locking units shown in FIG. 2. Access to the interior of cabinet 46
is provided by doors 48 and 50 which are separated by center post
49 of cabinet 46. Door 48 opens by pivoting about hinges 52 and 54.
In similar fashion, door 50 opens by pivoting about hinges 56 and
58. When upper locking unit 12 and lower locking unit 14 are in
their locked position, it is clear that neither door 48 nor door 50
is permitted to open. After doors 48 and 50 have been opened, they
may be returned to their locked position by merely closing doors 48
and 50. This causes shaft 28 of plunger 26 to ride up on either
contoured surface 40 or 41 (depending upon which door is closed
first) with the result that shaft 28 drops into opening 24 causing
the locking of doors 48 and 50.
FIG. 4 shows the locking units of FIG. 2 utilized to lock cabinet
doors 62 and 64 of cabinet 60. Cabinet door 62 is opened by
movement to the right as shown by the arrow. Cabinet door 64 is
opened by movement to the left as shown by the other arrow. As
shown in FIG. 4, it is clear that the downward displacement of
shaft 28 within opening 24 prohibits the opening of either cabinet
door 62 or cabinet door 64. Once opened, cabinet doors 62 and 64
may be locked by merely sliding cabinet doors 62 and 64 to their
closed position. This causes shaft 28 to ride up on contoured
surface 38 (FIG. 2) causing shaft 28 to drop into opening 24 of
lower locking unit 14.
FIG. 5 illustrates a second embodiment of the present invention.
Cabinet 66 having frame 80 includes door 68 which is slidable
therein in the direction shown by the arrow. Lower locking unit 72
is attached to frame 80 by screws 86 and 88. In a similar manner,
upper locking unit 70 is rigidly secured to door 68 by screws 82
and 84. Plate 74 covers the upper portion of upper locking unit 70
and is similar to plate 36 of the first embodiment. Upper locking
unit 70 is similar to upper locking unit 12 and includes plunger 76
which is similar to plunger 26 of the first embodiment. Similarly,
lower locking unit 72 is similar to lower locking unit 14 with the
exception that opening 78 is positioned to permit vertical mounting
of lower locking unit 72 to frame 80. Although screws are shown as
the means of attachment, other conventional means such as nails,
adhesives, etc., may also be utilized. As is evident from FIG. 5,
the downward displacement of plunger 76 into opening 78 prohibits
the opening of door 68. The upper surface of lower locking unit 72
may be contoured if the self-locking feature shown in the first
embodiment is desired. Alternatively, the self-locking feature may
be omitted by eliminating the contoured surface.
FIG. 6 illustrates a third embodiment of the present invention. As
shown in FIG. 6, cabinet 90 includes door 92 which is hinged to
frame 94 at hinge 108. The top portion of cabinet 90 is covered by
plate 96 which is similar in function to plate 36 of the first
embodiment. Lower locking unit 98 is rigidly secured to door 92 as
shown in the figure. Lower locking unit 98 includes an opening 100
and a contoured end portion 106. Slidably disposed within frame 94
is plunger 102 containing shaft 104. Plunger 102 is so positioned
as to cause shaft 104 to enter and pass through opening 100 in
lower locking unit 98 upon the downward displacement of plunger 102
within the relatively large diameter opening in frame 94. As shown
in FIG. 6, plunger 102, plate 96 and frame 94 perform the function
of upper locking unit 12 in the first embodiment. Similarly, lower
locking unit 98 performs the function of lower locking unit 14 in
the first embodiment. Contoured end portion 106 provides the
self-locking feature explained with respect to the first
embodiment. Thus, door 92 may be closed and locked by merely
closing it within frame 94 thereby causing plunger 102 to ride up
onto end portion 106 resulting in the entrance of shaft 104 through
opening 100. Door 92 includes knob 110 which may be utilized to
open the door after it has been unlocked. A significant feature of
the locking unit of the present invention utilized with cabinet 90
is that the external appearance of cabinet 90 when closed does not
give any indication that the cabinet is locked or if it is locked
or how it is locked. Further, there is no indication as to how
cabinet 90 may be opened.
FIG. 7 shows the third embodiment of the present invention as
utilized in a cabinet 112 having a frame 114, a door 116, and a
covering plate 122. Door 116 is opened by pulling knob 124 thereby
causing door 116 to pivot about hinges 118 and 120. As was also
explained with respect to FIG. 6, it is clear from FIG. 7 that the
external appearance of cabinet 112 gives no indication if it is
locked, how it is locked, or how it may be opened.
FIG. 8 illustrates a cross sectional view taken along lines 8--8 of
FIG. 7. As shown in FIG. 8, the locking of door 116 is accomplished
by the gravity caused downward displacement of plunger 102 and
shaft 104 through opening 100 in lower locking unit 98. To unlock
cabinet 112, it is only necessary to place a magnet above plunger
102 to cause the upward displacement of shaft 104 thereby
permitting a pulling upon knob 124 to cause door 116 to pivot about
hinges 118 and 120. As explained with reference to FIG. 6,
contoured portion 106 provides a self-locking feature for plunger
102. If this self-locking feature is to be omitted, contoured
portion 106 may be simply straightened so as to project
perpendicularly from the plane of door 116.
In order to prevent unauthorized openings of locked cabinets by
children, it is important that the magnet used to unlock the
cabinet be kept hidden or in a place where children will not be
able to remove it therefrom. In accordance with this requirement,
there is provided in accordance with the present invention a keeper
for securing the magnet. The keeper is horizontally mounted and is
comprised of a base 128 which is comprised of such a material so as
to attract magnet 44 thereto. Disposed adjacent to base 128 is wall
126 which has an inner periphery which is slightly larger than the
outer periphery of magnet 44. Wall 126 is of sufficient height so
that the only way magnet 44 can be withdrawn from plate 128 is by
removing magnet 44 in a direction almost perpendicular to the plane
of base 128. Therefore, if base 28 is horizontally mounted, magnet
44 may only be removed from its keeper by lifting it in a
substantially upward direction, which is difficult for children to
do since the substantial forces of magnetic attraction must be
overcome. Thus, as shown in FIG. 9, the magnet is "boxed-in" to
prevent unauthorized removal by children by twisting, sliding or
tilting of the magnet which is relatively easy for children to
do.
The present invention may be embodied in other specific forms
without departing from the spirit or essential attributes thereof.
For example, by way of illustration and not by way of limitation,
it is feasible to utilize two parallelly disposed plungers in the
upper locking unit and two openings in the lower locking unit and
have one magnet effect the simultaneous upward displacement of both
plungers. Accordingly, reference should be made to the appended
claims, rather than to the foregoing specification as indicating
the scope of the invention.
* * * * *