Note: Descriptions are shown in the official language in which they were submitted.
CA 02243340 1998-07-15
SWING DOOR LOCK FOR REFRIGERATED CABINET
FIELD OF THE INVENTION
This invention relates to a lock suitable for securing a swing door to a
refrigerated cabinet and is intended to dissuade pilfering.
BACKGROUND OF THE INVENTION
Refrigerated cabinets are generally provided for the convenience of customers
who require ready access to cold beverages for immediate consumption. Outside
of
regular business hours, it is sometimes desirable to restrict access to such
cabinets in
order to dissuade pilfering and yet it is problematic to find suitable locking
means
which are not awkward to use, which may readily be installed in the field, and
which are aesthetically pleasing.
An object of this invention is to provide a lock mechanism which may readily
be installed on a refrigerated cabinet without any structural modifications to
the
door and cabinet assembly and which is intended to dissuade pilfering.
SUMMARY OF THE INVENTION
In accordance with the invention, there is provided a lock assembly for a
swing door hinged to a cabinet, the lock assembly comprising a strike plate
having
a mounting plate adapted to be mounted to the cabinet, and a locking plate
spaced
from the mounting plate; a door bracket having an outer door plate adapted to
locate on an outer surface of the swing door, and a locking member mounted to
the
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being adapted to be disposed between the mounting plate and locking plate of
the strike
plate and to locate against the locking plate to lock the swing door to the
cabinet in a first
angular position of the locking shaft, and the locking member being adapted to
be released
Erom the locking plate to unlock the swing door in a second angular position
of the locking
shaft.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention is now described belo~~ with reference
to
t:he accompanying drawings in which,
Fig. 1 is an assembly drawing showing a strike plate for mounting to a
cabinet;
I?ig. 2 is an assembly drawing showing a barrel lock in association with a
door bracket in
accordance with the invention;
Fig. 3 is a side elevation view of the door lock in accordance with the
invention associated
with a swing door and cabinet assembly;
Fig. 4 is a similar view to Fig. 2 from the opposite side and showing the door
lock assembly
in association with a swing door and cabinet assembly;
Fig. 5 is a similar view to Fig. 3 showing a first alternative embodiment of
the invention;
Fig. 6 is a similar view to Fig. 2 showing a second alternative embodiment of
the invention;
Fig. 7 is a similax view to Fig. 3 showing second alternative embodiment of
Fig. 6; and
Fig. 8 is a perspective view of alternative embodiment.
DESCRIPTION OF PREFERRED EMBODIMENT
As indicated above, the invention relates to a door lock which is used to
secure a
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swing door which is hinged to a cabinet and finds particular application to
refrigerated
c:abinets which are used for self serve access to cold beverages or other
refrigerated items.
(Jnly portions of a refrigerated cabinet are shown in the accompanying
drawings as their
basic structure is already well-known to those skilled in the art.
In Fig.1, there is illustrated the top left corner of a cabinet generally
indicated by the
numeral 20 and having an upper wall 22 disposed horizontally adjacent to a
vertically
extending side wall 24. Together, the upper wall and side wall define a front
opening 26 for
accessing the cabinet interior. A door 28 (Fig. 3) is hinged to the right of
the cabinet
opening 26 (as drawn), in a manner which is well known in the art and which is
not shown
in the drawings.
It will be appreciated that the swing door 28 may alternatively be hung on the
left
side of the cabinet which conveniently is pre-drilled with suitable threaded
openings 30
adapted to receive mounting bolts 32.
Conveniently, a strike plate 34 forming part of the lock assembly of the
invention is
mounted to the cabinet 20 using the pre-drilled threaded openings 30 and
mounting bolts
32, thereby greatly facilitating field installation of the lock assembly. The
strike plate 34
comprises a sheet metal plate bent into a U-shaped configuration and defining
a mounting
plate 36 which is apertured to receive the mounting bolts 32 and, in use, is
disposed adjacent
to the cabinet 20. A locking plate 38 is forwardly spaced from the mounting
plate 36 by a
transversely-extending connecting web 40 and is somewhat shorter in height
than the
mounting plate so as to permit ready access to the mounting bolts 32 and
associated washers
33. A rectangular opening 42 is formed in the locking plate 38 and is adapted
to receive a
locking member 90 as will be described in more detail further belo~~.
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A door bracket in the form of a "saddle" cooperates with a free edge of the
swing
door 28 and is generally indicated in Figs. 2 to 4 by reference numeral 44.
The door bracket
comprises an outer door plate 46 having a first vertically extending portion
48 (as drawn)
which, in use, locates against the outer surface 51 of the swing door 28, a
first horizontally
extending portion 50 which is orthogonal to the first vertically extending
portion and locates
against the top free edge 52 of the swing door, a second vertically extending
lock receiving
portion 54 having a square opening 56 (Fig. 2) formed therein and adapted to
receive a
barrel lock 58. A second horizontal portion 60 extends further inwardly toward
the cabinet
2.0 and is spaced by the second vertically-extending portion 54 so as to
overhang the
connecting web 40 of the strike plate 34.
The door bracket further comprises an inner door plate 62 which, likewise, has
a first
vertically extending portion 64 (as drawn) which, in use, is adapted to locate
against an inner
surface G6 of the swing door 28. The inner door plate 62 also has a first
horizontal portion
68 which is adapted to locate against the top free edge 52 of the door and a
second vertically
extending portion 70 comprising spaced apart flanges and dimensioned to be
accommodated under the second horizontal portion 60 of the outer door plate
46.
The outer door plate 46 and inner door plate G2 each have transversely spaced
apemires 74, 72 respectively in their second vertically extending portions 54,
70 which
receive a pair of fasteners 76.
The barrel lock 58 comprises a spring-biased key-operated barrel plunger 78
which
is. rotatably received in a barrel housing 80 mounted to a base plate 82 which
defines a pair
of outwardly extending flanges on opposite sides of the barrel lock and each
having a
threaded aperture 84 adapted to cooperate with the fasteners 76. In the
embodiment
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illustrated, the barrel lock 58 is permanently mounted to the saddle bracket
such that the
barrel housing 80 is received in the square opening 56 of the outer door plate
4G and the
base plate 82 is sandwiched between the inner and outer door plates 62, 46, as
can be seen
most clearly in Fig. 3.
The internal construction of the barrel lock is not shown in the drawings but
will be
apparent to those skilled in the art. A locking shaft 86 (Fig. 4) is coupled
to the barrel
plunger 78 for rotation with the barrel upon operation of a key 88 (not
shown). The locking
shaft 8G has a locking member in the form of a T-bolt 90 which is dimensioned
to be
received between the flanges of the second vertical portion 70 and through the
rectangular
opening 42 in the locking plate 38 of the strike plate 34. It will be
understood that the T-
bolt 90 can slide in and out of the opening 42 in an unlocked angular
orientation of the
barrel plunger 78 and that the T-bolt 90 is adapted to locate against the
locking plate 38 in
other angular positions of the barrel plunger and the associated locking shaft
86.
In use, the door bracket and barrel lock assembly can be removed from the
cabinet
2;0 by releasing the T-bolt 9U from the strike plate 34. In this way, there
are no unsightly
devices which are exposed to view during normal operating hours, the only
permanently
attached portion of the lock assembly being the strike plate 34. Also, since
the strike plate
34 is mounted using the existing pre-drilled holes for alternative location of
the swing door
28 on the cabinet 20, there is no permanent deformation of the cabinet and the
door is left
unmarred.
It will be appreciated that the lock assembly is intended to be used as a
deterrent only
itz order to discourage pilfering. To some extent, the second horizontal
portion GO of the
outer door plate 46 obstructs access to the locking shaft 86 in order to
minimize tampering
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with the device. However, the lock assembly is not intended to be used to
protect any
valuables in the associated cabinet.
In a first alternative embodiment of the invention, the lock assembly
indicated by
reference numeral 92 in Fig. 5 comprises a strike plate 34 which is similar to
that in Figs. 1
to 4 and has like parts identified by like numerals. However, the door bracket
94 does not
include an inner door plate 62. The remaining components of the door bracket
94 are
identified by like numerals to those used in Figs. 1 to 4. It will be seen
that the barrel lock
~i8 is therefore fixed directly to the door bracket 94 and is stabilized when
the T-bolt 90
Engages the locking plate 38.
In a second alternative embodiment of the invention drawn in Figs. 6 and 7,
the door
bracket is identified by reference numeral 96 and comprises inner and outer
door plates 98,
100, each having a respective first vertical portion 102, 104 adapted to lie
against the inner
a.nd outer surfaces of a door 28, oppositely directed horizontal portions 106,
108 adapted
to lie on the top free edge of the door 28, and respective second vertical
portions 110, 112
extending upwardly above the associated door, the second vertical portions
having
respective openings 114, 116 formed therein to receive a cam lock assembly
118.
The cam lock assembly 118 has a key-operated locking shaft 120 having a
squared
end and rotatable inside a housing 122 having flat sides on opposite sides
thereof for
location in the openings 114, 116 which likewise have flat sides. The
remainder of the
housing 122 is threaded for cooperation with a thxeaded washer 124 whereby the
cam lock
assembly 118 is secured to the door bracket 96.
A locking member in the form of a pawl 126 pivoted to the locking shaft 120 is
adapted to pivot with angular movement of the locking shaft 120 actuated by a
key (not
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shown) and received in key slot 128. The pawl 126 has a square opening 130 to
fit on the
squared end of the locking shaft 120 and is secured in position by a washer
132 and a bolt
7.34 received in a threaded opening (not shown) formed in the end of the
locking shaft 120.
A strike plate generally indicated by numeral 136, in Fig. 7, has a mounting
plate 138
attached to a cabinet 20 by fasteners 140 and a locking plate 142 is spaced
from the
mounting plate 138 to receive the pawl 126 therebetween. It will be understood
that the
pawl 126 may be pivoted to a horizontal orientation where the cam lock
assembly 118 is in
a, release position and it may be pivoted to a vertical orientation, as drawn,
where the pawl
126 locates against the locking plate 142 to lock the swing door 28 to the
cabinet 20.
In this embodiment, the locking plate is nat apertured to receive the locking
member, unlike the embodiment of Figs. 1 to 4. Several other variations may be
made to
the embodiments described above, within the scope of the appended claims.
It will be appreciated that many cabinets are constructed so that the upper
wall 22
aloes project upwardly above the maximum height of the associated door 28, as
drawn in
t:he accompanying figures. Conveniently, the lock assembly of the invention
will occupy the
space between the upper free edge of the door and the cabinet and only
protrude a small
height above the cabinet. However, it will be appreciated that the lock
assembly may also
h~e modified so that it will be suitable for cabinets in which the door is
mounted so that its
free edge is of commensurate height as the cabinet upper wall and,
alternatively, could be
adapted for mounting to the side wall of the cabinet as the case may be.
For example, in an alternative embodiment shown in Figure 8, the lock assembly
indicated by reference numeral 150 comprises a strike plate 152 attached to a
side of the
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c:abinet. The strike plate 152 comprises a metal plate bent to define a
locking plate 154 (38).
A door bracket generally indicated by reference numeral 156 (44) cooperates
with a free side
edge of the door 28. The door bracket 156 has an outer door plate 158 (48)
which locates
against the outer surface 160 of the door and a transverse portion orthogonal
162 (50) to
the first portion and adapted with and locate against the side free edge 164
of the door. A
lock receiving portion 166 is orthogonal to the transverse portion 162 and has
an opening
7.68 adapted to receive a lock 170. An extending portion 172 extends inwardly
towards the
c;abinet over the strike plate 154. The door bracket further comprises an
inner door plate
7.74 which has corresponding plates adapted to fit onto the inner surface of
the door. The
inner door plate and the outer door plate both have apertures in their lock
receiving
portions which receive a pair of fasteners 178. Other variations may be made
to the
invention, as will be apparent to those skilled in the art.
20
_g_
