Note: Descriptions are shown in the official language in which they were submitted.
i~O4366
CAM-TYPE DOOR LOCK WITH RECESSED HANDLE
The present invention relates generally to door locks
of the type used on large doors of moving vans and the like, and,
more particularly, to a door lock including a lockable recessed
handle.
Door locks of the type including an elongate shaft
pivotally supported on a pivoted door and carrying cam members on
opposite end regions of the shaft for releasably engaging keeper
members carried on opposite sides of a door frame to retain the
door in a closed position, are well known. Locks of this type
are typically provided with a handle connected to the shaft for
rotating the shaft to bring the cam members into and out of
engagement with the keeper members. Such locks are commonly used
on semi-trailer truck doors and the like.
Locks of the type described having a pan-shaped housing
in which the handle is nested when the lock is locked, are also
well known. Such locks are frequently used on the side doors of
moving vans and the like where it is desired that the handle not
project beyond the outer surface of the door when the door is
locked. One such lock is sold by Eberhard Manufacturing Company,
Cleveland, Ohio 44136, under the model designation 5661.
It is known to provide the handles of locks such as
Eberhard model 5661 with a key-operated lock cylinder to retain
the operating handle in a locked position. A drawback of proposals
for providing a key-operated cylinder in such a lock is that
components of the resulting assembly can be bent, broken, or
otherwise damaged by the application of undue force, as during
tampering, whereby the locking action of the assembly is readily
overcome. MoreoYer, previous proposals in no way provide a back-
up or secondary locking system which will operate to maintain thelock locked even if the locking action of the primary locking
system has been oYerCome.
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It is also known to pro~ide the handles of locks such
as Eberhard model 5661 with a handle return spring interposed
between the pan-shaped housing and the handle itself. A drawback
of previous proposals has been that the spring rubs against the
handle and causes the protective, corrosion resistant finish
applied to the handle to be worn away ~uite rapidly.
The present invention overcomes the foregoing and other
drawbacks of prior art proposals by providing a novel and improved,
cam-type door lock having a recessed handle and an improved
locking system for retaining the handle in its nested position.
In the preferred practice of the present invention, a
door lock of the type used to lock a pivotall~ mounted door in a
closed position includes a pair of keeper members adapted to be
secured to a door frame near two opposite edges of the door
opening defined by the door frame. The edges selected to support
the keeper members are those which extend transversely to an axis
about which a door is mounted for pivotal movement relative to
the door frame. The door lock further includes an elongate shaft
structure which is adapted to be secured to the door with the
longitudinal axis of the shaft being spaced from and extending
substantially parallel to the pivot axis of the door. Two cam
members are each secured to opposite end regions of the shaft and
are rotatable with the shaft to selecti~ely releasably engage the
keeper members to hold the door in a closed position.
A housing is provided for mounting in an opening formed
in the door. The housing has sidewalls and a backwall which
cooperate to define a forwardly facing recess, and has a pair of
aligned openings formed in opposite sidewall portions. The shaft
structure has a central portion which extends through the openings
and through the recess. An elongate handle has one end portion
secured to the central portion oI the shaft structure. The
handle is rotatable with the shaft structure relati~e to the
housing between a nested position wherein the handle is nested
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within the recess, and a projecting position wherein the other
end portion of the handle projects forwardly from the recess.
A latch mechanism is carried by the housing and includes
a latch member mounted for pivotal movement between latched and
unlatched positions. The latch member is operable to engage and
releasably retain the handle in its nested position when the
latch member is in its latched position and the handle is in its
nested position. A key-operated lock cylinder is carried by the
handle. A lock member is movable by the lock cylinder between
locked and unlocked positions as a key is turned in the lock
cylinder. The lock member is operable to retain the latch member
in its latched position when the handle is in its nested position.
A lock member reinforcing structure is carried by the
housing and defines a formation which receives the lock member
when the handle is in its nested position and when the lock member
is in its locked position. The lock member reinforcing structure
not only operates to support and rigidify the lock member, thereby
preventing the lock member from being bent, broken, or otherwise
damaged by the application of undue force to the latch member,
but also cooperates with the lock member to define a back-up or
secondary lock which will retain the handle in its nested, locked
position even if the latch member is broken by an application of
undue force.
The latch member preferably has a projection which
pivots forwardly as the latch member is moved from its latched
position toward its unlatched position. ~he lock member preferably
has an end portion which overlies the projection to prevent
movement of the latch member toward its unlatched position when
the handle is in its nested position, when the latch member is in
its latched position, and when the lock member is in it~ locked
position. The receiving formation on the lock member reinforcing
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1104366
structure preferably takes the form of a slot which receives the
lock member end portion at a location adjacent to the latch
member projection to prevent the transfer of excessive moment
forces along the lock member in response to an application of
undue force on the latch member.
Another feature of the preferred practice of the present
invention lies in its provision of a handle return spring inter-
posed between the pan-shaped housing and the shaft structure.
Unlike prior proposals wherein a handle return spring has been
located within the recess defined by the pan-shaped housing, the
present invention provides a torsion coil handle return spring
located out of sight and at a protected position behind the front
face of the housing. ~oreover, unlike prior proposals, the
handle return spring does not operate directly on the handle
itself, and therefore does not cause the protective finish on the
handle to be worn away.
As will be apparent from the ~oregoing summary, a feature
of the present invention resides in its provision of a novel and
improved door lock. A further feature resides in the provision
of a door lock of the type described with a simple and inexpensive
means to render its elements more resistant to tampering.
These and other features and a fuller understanding
of the invention described in the present application may be had
by referring to the following description and cla~ms taken in
conjunction with the accompanying drawing.
FIGURE l is a foreshortened side eleYational view of a
door lock embodying the preferred practice of the present inven-
tion;
FIGURE 2 is a sectional view as seen from a plane
indicated by a line 2-2 in FIGURE l;
FIGURE 3 is a sectional view as seen from a plane
indicated by a line 3-3 in FIGURE 1, and showing in phantom a cam
member moved to its door unsecured position;
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66
FIGURE 4 is a sectional view similar to FIGU~E 2 showing
the handle of the door lock moved out of its nested position;
FIGURE S is a top plan view of portions of the door
lock as seen from a plane indicated by a line 5-5 in FIGURE 4;
FIGURE 6 iS a sectional view similar to FIGURE 2 showing
a portion of the door lock with the latch member moved to its
unlatched position;
FIGURE 7 is a sectional view similar to FIGURE 2 showing
a portion of the door lock with the latch member having a portion
broken off, as may occur if the lock is tampered with while
locked; and
FIGURE 8 is an enlarged side elevational view similar
to FIGURE 1 illustrating how a handle return spring is preferably
incorporated in the lock of FIGURE 1.
Referring to FIGURE 1, a door lock embodying the preferred
practice of the present invention is indicated generally by the
numeral 10. The door lock 10 includes a pair of keeper members
12, 14, which are secured to top and bottom parts of a door
frame, indicated by numerals 16, 18. The door lock 10 additionally
includes an assembly 20 which is mounted on a pivoted door.
Upper, lower and intermediate portions of the pivoted door are
indicated by the numerals 22, 24, 26.
The assembly 20 includes an elongate shaft 30. The
shaft 30 is preferably formed as an assembly of several inter-
25 fitting cylindrical and/or tubular parts, but may be formed inone piece, if desired. A pair of brackets 32, 34 journal the
shaft 30 for rotation about an axis indicated by the numeral 36.
The door on which the assembly 20 is mounted is pivoted about an
axis, not shown, which pivot axis is spaced from and extends
parallel to the axis 36. The pivot axis of the door would normally
be located to the right of the assembly 20 in the embodiment
shown in FIGURE 1.
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The assembly 20 additionally includes a pair of cam
members 40, 42 which are secured to opposite end regions of the
shaft 30. The cam members 40, 42 are mirror images of Pach other
and include transversely extending arm portions 44, 46. The
keeper members 12, 14 are mirror images of each other and include
projecting portions 48, 50 which project toward the door portions
22, 24. The cam members 40, 42 are rotatable with the shaft 30
between a door unsecured position, shown in phantom in FIGURE 3,
and a door secured position, shown in solid lines in FIGURES 1
and 3. When the cam members 40, 42 are in the door unsecured
position, their arm portions 44, 46 will move freely past the
projecting portions 48, 50 when the door i6 pivoted about its
pivot axis. When the cam members 40, 42 are in the door secured
position, and when the door is in its closed position, the arm
portions 44, 46 extend behind the projecting portions 48, 50 to
retain the door in its closed position.
The assembly 20 further includes a handle 60 which is
operable to rotate the shaft 30 to position the cam members 40,
42, and a housing assembly 62 within which the handle 60 may be
nested. A latch assembly 64 is provided to releasably retain the
handle 60 in its nested position, and a key-operated lock cylinder
66 is carried by the handle 60 for selectively locking the handle
60 in its nested position.
Referring to EIGURES 1 and 2, the housing assembly 62
includes an elongate, pan-shaped housing 70 stamped from sheet
metal. The housing 70 has a backwall 72 and sidewalls 74 which
cooperate to define a forwardly facing recess 76. The housing 70
has a rim 78 which extends peripherally around its forward face.
The housing 70 is positioned within an opening 28 formed in the
door portion 26, and has its rim 78 overlying such parts of the
door portion 26 as define the opening 28. The housing 70 is
secured to the door portion 26 as by welding or by some other
suitable conventional fastening system.
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1~04366
The shaft 30 has a central portion 80 which extends
throu~h aligned openings 82 formed in opposlte portions of the
sidewalls 74, and through the forwardl~ facing recess 76. The
handle 60 has an end portion 84 which is secured to the central
portion 80, and an opposite end portion 86 of réduced cross-
section which is configured to be gripped conveniently by the
fingers of one's hand.
The handle 60 has an intermediate portion 90, through
which a slot 92 and a hole 94 are formed. The latch assembly 64
includes a latch member 96 which projects through the slot 92
when the handle is in its nested position. The lock cylinder 66
has a threaded shank 98 which extends through the hole 94. A nut
100, or other suitable fastener secures the lock cylinder 66 to
the handle 60.
Referring to FIGURES 2, 4, 5 and 6, the latch assembly
64 includes a mounting bracket 110 which is secured to the backwall
72 as by spot welding. The bracket 110 has a pair of forwardly
extending arms 112 which extend alongside a central portion 114
of the latch member 96. A pin 116 extends through aligned holes
formed in the arms and in the portion 112, 114 to pivotally mount
the latch member 96 on the bracket 110. A torsion coil spring
has coils 118 which wrap around the pin 116 at locations on
opposite sides of the central portion 114, and has end portions
122 which bear against the bracket 110 and the latch member 96 to
bias the latch member 96 counter-clockwise, as viewed in FIGURES
2, 4 and 6.
The latch member 96 has a notch 120 which is configured
to engage the central handle portion 90 adjacent one edge of the
slot 92 when the handle 60 is in its nested position. When the
latch member notch 120 is engaging the handle portion 90, as
shown in FIGURE 2, the latch member 96 is in its latched position
and operates to retain the handle 60 in its nested position. The
torsion spring coil 118 are operative to bias the latch member 96
toward, and to retain the latch member 96 in, its latched position.
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1104366
The latch member 96 may be pi~oted about the axis of
the pin 116 between its latched position and an unlatched position,
shown in FIGURE 6. When the latch member 96 is in its unlatched
position, the handle 60 may be pivoted about the shaft axis 36
between its nested position, as shown in FIGURE 2, and projecting
positions, one of which is illustrated in FIGURE 4.
The latch member 96 has a foot 124 which projects
leftwardly, as viewed in FIGURES 2, 4, 5 and 6, toward the lock
cylinder 66. When the latch member 96 is in its latched position,
10 the foot 124 abuts the bracket 110. When the latch member 96
pivots away from its latched position, the foot 124 pivots for-
wardly, as shown in FIGURE 6.
~ he lock cylinder 66 carries a lock member 130 which is
rotatable between locked and unlocked positions when a key is
turned in the lock cylinder 66. The locked position of the lock
member is shown in FIGURE 2, and the unlocked position in FIGURES
4 and 6. The lock member 130 has an end portion 132 which overlies
the foot 124 when in its locked position, and which is spaced to
the left of the foot 124, as viewed in FIGURE 6, when in its
unlocked position.
The locking engagement established between the locking
member 130 and the latch member foot 124, and between the latch
member notch 120 and the handle portion 90, provides a primary
locking system which will, in normal use, effectively retain the
handle 60 in a nested, locked position. Such a primary locking
system, howe~er, suffers the drawback that, if a person seeking
unauthorized entry tampers with the lock 10 by subjecting the
latch member portion 96 to excessive rearward pressure, tending
to pivot it clockwise about the pin 116, as viewed in FIGURES 2,
4 and 6, damage may result to the lock components causing them to
cease their locking function. One type of damage which may occur
is for the locking member 130 to be bent forwardly to a degree
which will permit the latch member 96 to pivot to a position
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1104366
where the notch 120 will no longer engage the handle portion 90.
Another type of damage which may occur is that the latch member
96 may be broken by the application of excessive force whereby
its notched portion no longer engages the handle 90 and permits
the handle 60 to be pivoted out of its nested position.
In accordance with a particularly advantageous feature
of the present invention, a lock member reinforcing structure 140
is mounted on the backwall 72 as by spot welding or by some other
suitable conventional fastening system. The reinforcing structure
140 preferably takes the form of an L-shaped bracket having an
upstanding leg 142. The reinforcing structure 140 has a lock
member receiving formation, preferably taking the form of a slot
144 provided in the upstanding leg 142. The slot 144 is positioned
so that, when the lock member 130 is rotated to move its end
; 15 portion 132 into overlying engagement with the foot 124, the end
portion 132 will project through the slot 144. When the end
portion 132 is projecting through the slot 144, as shown in
FIGUR~ 2, the reinforcing structure 140 operates to support and
rigidify the lock member 130 so that, in the event that excessive
inward force is applied to the latch member 64, the lock member
- 130 will not be bent out of shape to a degree which will permit
the latch member notch 120 to disengage the handle portion 90.
In this way, the reinforcing structure 140 operates to reduce the
possibility of lock damage due to the application o~ undue force,
and substantially reduces the likelihood that the primary locking
system may fail during tampering.
A significant additional feature of the reinforcing
structure 140 is that it cooperates with the lock member 130 to
establish a back-up or secondary locking system which will be
operable to maintain the handle 60 in its nested, locked position
even in the event of failure of the latch member 96 to perform its
primary locking function. As is illustrated in FIGURE 7, if an
excessive amount of inward force has been applied to the latch
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1104366
member 96, sufficient to break off the upper portion of the latch
member 96, the interfitting engagement which is still established
between the lock member 130 and the reinforcing structure 140
will be operable to maintain the handle 90 in its nested, locked
position. It will still be necessary to utilize a key inserted
in the lock cylinder 66 to rotate the lock member 130 to its
unlocked position before the handle 60 can be moved out of its
nested, locked position.
The latch member 96 is preferably formed using powder
metallurgy techniques to provide a relatively rigid, smooth-
finished component at relatiYely low cost. A hole 150 is provided
through the upper portion of the latch member 96 to permit the
hasp of a padlock to be inserted therethrough to pro~ide an
additional, third, locking action which will further enhance the
secure locking of the handle 60 in its nested position.
Referring to FIGURE 8, in preferred practice, a handle
return spring 160 is interposed between the shaft 30 and the pan-
shaped housing 70 to bias the handle 60 toward its nested position.
The spring 160 has torsion coils 162 which wrap around a portion
of the shaft 30, and an elongate lower end 164 portion which
engages the back face of the housing rim 78. A collar 166 drivingly
engages an upper end portion 168 of the spring 160. A pair of
set screws 170 drivingly connect the collar 168 to the shaft 30.
A feature of the biasing action of the handle return
spring 160 is that it pre~ents the handle 60 from being acci-
dentally left in a position where it can do damage to the side-
wall of a truck on which the door is mounted. If, for example,
the handle 60 were left in a fully open position wherein the
handle end 96 extends in a plane perpendicular to the plane of
the door, when the door is opened, the handle end 86 may impact
the sidewall of the truck, and may eYen puncture the sidewall.
The biasing action of the spring 160 will prevent the handle 60
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11043~;6
from remaining in its fully open position once it has been re-
leased by an operator. The biasing action of the handle return
spring 160 need not be so strong as to cause the handle 60 to
assume its nested position when released, although a biasing
strength of this magnitude may be desired.
By interposing the handle return spring 160 between the
housing 70 and the shaft 30, rather than between a housing and a
handle, as has been done in accordance with prior proposals,
several advantages obtain. The spring 160 is concealed from view
and is protected from exposure to road salts and the like which
- may splash on exposed parts of the lock 10. The spring 160 may
be easily installed on the shaft 30, thereby minimizing assembly
problems. Moreover, the spring 160 does not act directly against
surface portions of the handle and therefore does not cause the
protective corrosion-resistant finish on the handle to be worn
away.
As will be apparent from the foregoing description, the
present invention provides a novel and improved door lock assembly
having latch and locking components for retaining a recessed
handle in its nested, locked position, with primary and back-up
locking systems which are well adapted to withstand an application
of undue force. The simplicity of the system is enhanced by the
use of a single reinforcing structure of elemental configuration
which not only supports and rigidifies the lock components but
also enhances their operation by providing a back-up locking
action which will retain the handle in a locked position in the
event the primary locking system is disabled.
Although the invention has been described in its preferred
form with a certain degree of particularity, it is understood
that the present disclosure of the preferred form has been made
only by way of example and numerous changes in the details of
construction and the combination and arrangement of parts may be
resorted to without departing from the spirit and scope of the
1104366
invention as hereinafter claimed. It is intended that the patent
shall cover, by suitable expression in the appended claims,
whatever features of patentable novelty exist in the invention
disclosed.
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