Note: Descriptions are shown in the official language in which they were submitted.
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KEY OPERATED LATCH WITH COMBINED ROTATIONAL AND
TRANSLATIONAL LATCHING ACTION
TECHNICAL FIELD
The present invention relates generally to latching devices and more
particularly to
latching devices for securing a first member such as a door, panel or the like
in a closed
position relative to a second member such as a corresponding door, panel or
frame.
BACKGROUND ART
Various types of latching devices for use in securing a first closure member
such
as a door, panel or the like in a closed position relative to a corresponding
second closure
member such as a door, panel or frame are known. Some types incorporate a pawl
or
similar latching member that is actuated to engage a closure member for
latching. In
particular, latches have been proposed which operate to move the latching
member both
rotationally and translationally to engage a closure member for latching. For
example,
U.S. Patent Number 5,165,738, issued to Edward McCormack on November 24, 1992,
U.S. Patent Number 4,878,367, issued to Robert H. Bisbing on November 7, 1989,
U.S.
Patent Number 4,583,775, issued to Robert H. Bisbing on April 22, 1986, and
U.S.
Patent Number 4,556,244, issued to Robert H. Bisbing on December 3, 1985, all
show
latching mechanisms with a combined rotational and translational latching
action.
However, none of the references cited previously teach or suggest the unique
structural
features of the key operated latch of the present invention.
DISCLOSURE OF INVENTION
The present invention is generally directed to a key operated latch for use
with a
door, panel or the like. The latch includes a housing having a bore, a first
end, and a
3 0 second end. A lock plug, a lock plug sleeve, a motion control sleeve, and
a sleeve-like
cam are received within the bore of the housing. The lock plug sleeve and the
motion
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control sleeve are supported within the housing such that they are stationary
relative to the
housing. The lock plug is positioned coaxially with the lock plug sleeve and
is selectively
rotationally movable relative to the lock plug sleeve by using a key. The
sleeve-like cam is
coupled to the lock plug such that it rotates with the lock plug. The sleeve-
like cam has at
least one cam slot, and the motion control sleeve has at least one motion
control slot. The
latch further includes a shaft which is positioned at least in part within the
housing, with a
portion of the shaft extending outward from the second end of the housing. The
shaft has
at least one projection which is engaged with both the cam slot and the motion
control
slot. The cam slot and the motion control slot are configured such that
rotation of the
lock plug imparts movement to the shaft which is a sequence of movements
including a
rotational movement and an axial movement. A latching member is supported by
the shaft
outside the housing such that the latching member and the shaft move as a
unit. Thus, the
latching member moves between a latched position and an unlatched position in
a
sequence of axial and rotational motions in order to selectively, releasably
secure the door,
panel, or the like in the closed position.
Accordingly, it is an object of the present invention is to provide a novel
key
operated latch.
Another object of the present invention is to provide a novel latch of the
type
incorporating a pawl or similar member and which is actuated through operation
of a key.
2 0 Yet another object of the present invention is to provide a novel key
operated
latch where the pawl moves both rotationally and axially.
Still another object of the present invention is to provide a novel latch
which
applies a compressive force between first and second closure members.
These and other objects of the present invention will become more readily
2 5 apparent when taken into consideration with the following description and
the attached
drawings.
BRIEF DESCRIPTION OF DRAWINGS
3 0 Figs. 1-7 are views of a latch assembly in accordance with an embodiment
of the
present invention.
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Fig. 8 is an exploded view of the latch assembly of figs. 1-7.
Figs. 9-16 are views of a bushing, slightly enlarged, of the latch assembly of
fig. 8.
Figs. 17-24 are views of a lock plug sleeve, slightly enlarged, of the latch
assembly
of fig. 8.
Figs. 25-31 are views of a motion control sleeve, slightly enlarged, of the
latch
assembly of fig. 8.
Figs. 32 and 33 are views of a housing, slightly enlarged, of the latch
assembly of
fig. 8.
Fig. 34 is a side elevational view of a cam, slightly enlarged, of the latch
assembly
of fig. 8.
Fig. 35 is a top plan view of a retainer, slightly enlarged, of the latch
assembly of
fig. 8.
Fig. 36 is a cross sectional view of the latch assembly of figs. 1-7 taken
along the
line 36-36 of fig. 2.
Figs. 37-39 are side elevational views of the latch assembly of figs. 1-7,
slightly
enlarged, with the housing and sleeve portions in section and the latch
assembly being
shown in a closed or latched position in fig. 37, in an open or unlatched
position in fig. 39
and in a transitional position between the closed and open positions in fig.
38.
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention is directed to a key operated latch that has broad
application
and may be used with a wide variety of closure members, such as a door or the
like, for
2 5 releasably securing a closure member in the closed position.
Illustrated in the figures is one embodiment of a latch in accordance with the
present invention. The particular latch illustrated in the present embodiment
is similar in
many aspects to a latch shown, described and claimed in U.S. Patent No.
4,583,775('755
Patent) entitled "Latch Assembly Having Pull-Up Action", which is incorporated
by
3 0 reference herein. For the sake of brevity, emphasis will be made in the
following
SUBSTITUTE SHEET (RULE 26)
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description to the features in the present embodiment which differ from that
set forth in
the '775 Patent.
As illustrated in the figures, the latch assembly 10 in accordance with the
present
embodiment includes, as portions thereof, a housing 30, a shaft 50 having an
end 54,
fastening means comprising in this embodiment a latching pawl 70 mounted on
the
threaded end of the shaft 50 as by mounting nuts 71, and actuating means
comprising in
this embodiment a sleeve-like cam 20, a motion control sleeve 40, a cross-pin
60, a lock
plug 11 l, a lock plug sleeve 113, a bushing 115, a retaining ring 117 and a
key 119, the
details of which will be described below.
In the present embodiment, the latching pawl 70 is movable rotationally by
shaft
50 and is also moveable by shaft' S0 axially in the longitudinal direction of
the shaft. In
operation, the latch assembly 10 is mounted in an opening through one member,
such as a
closure member, and the pawl is moved to engage a second member, such as a
corresponding frame. To latch the closure member to the frame, the latching
pawl 70 is
first rotated to a position such that it is in fine with the fi~ame member.
The latch pawl 70
is then moved longitudinally so that it engages the edge of the frame. The
shaft 50 is
moved rotationally and also longitudinally by means of the actuating means.
The lock plug I 11 is generally cylindrical and in the nature of a
conventional lock
plug including a key access opening and an array of wafers that retract upon
insertion of
2 0 the key 119. The lock plug sleeve 113 is also generally cylindrical and
includes a bore 18
generally cylindrical in configuration and which receives the lock plug 11 I.
The bushing
115 comprises a generally annular member in this embodiment including an
opening 130
therethrough and operates to retain the internal components, including the
lock plug 1 I 1,
lock plug sleeve I 13, sleeve-like cam 20, motion control sleeve 40 and cross-
pin 60. The
2 5 retaining ring 117 is also a generally annular member and operates to hold
the foregoing
components of the actuating means within the housing 30.
The housing 30 in the present embodiment is a generally elongate component
having a first end, a second end, a bore extending longitudinally through the
housing 30
and an outer surface. The second end 32 of housing 30 has a central opening,
contiguous
3 0 with the bore of the housing 30, through which the shaft 50 passes. As
used herein, the
distal end of a component part refers to that end of the component part which
is located
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farthest from the first end of the housing 30, when the latch 10 is fully
assembled, while
the proximal end of a component part is the end closest to the first end of
the housing 30,
again when the latch 10 is fully assembled. In the present embodiment, the
distal ends of
the motion-control sleeve 40 and sleeve-cam 20 abut against the end wall
surrounding the
5 central opening in the second end 32 of the housing 30. The lock plug 111
and lock plug
sleeve 113 are positioned within the bore of the housing 30 adjacent to the
first end 33 of
the housing 30. The outer surface of the housing 30 includes a flanged first
portion 35
adjacent to the first end 33. The outer surface of the housing 30 also
includes a second
portion 37. The second portion 37 of housing 30 is provided with intemrpted
screw
threads along a portion of the outer surface thereof. The screw threads on the
outer
surface of the second portion 37 of the housing 30 are interrupted by four
flats formed on
the outer surface of the housing 30. The flats formed on the outer surface of
the housing
30 prevent the rotation of the housing 30 when the key 119 is used to turn the
lock plug
111, once the latch 10 is installed in a closure member such as a door or the
door's fi-ame.
The intemrpted threads on the outer surface of the housing 30 are engaged by a
nut to
secure the catch 10 in place, once the latch 10 is installed in a closure
member such as a
door or the door's frame.
In the present embodiment, the lock plug 1 I 1 is rotatable within the housing
30
and is prevented from movement in the axial direction, i.e. along the
longitudinal axis of
2 0 the housing 30, by the retaining ring I 17. The retaining ring 117 is
received within
grooves 13 and 161, which are located in the bushing 115 and the housing 30,
respectively, and are in registry with one another. As a result, the bushing 1
I S and
retaining ring 117 rotate on rotation of lock plug 111. In addition, means are
provided
between the lock plug 111 and cam 20 for providing for the rotation of the cam
20 on
2 5 rotation of the lock plug 111. In the illustrated embodiment, the distal
end of the lock plug
111 is provided with a pair of notches 16 which receive ears 21 projecting
axially from the
proximal end of the cam 20. Thus, when lock plug 1 I 1 is rotated, as by the
key 119, the
sleeve-like cam 20 is also rotated. The sleeve-like cam 20 is provided with at
least one
and, in the present embodiment, a pair of cam slots 25 spaced 180°
apart
3 0 circumferencially. Each of the slots 25 run in a direction which has both
circumferencial
and axial components.
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The lock plug sleeve 113 in this embodiment is received in housing 30 in a
substantially fixed rotational position. As illustrated, the lock plug 111 is
substantially
surrounded by lock plug. sleeve 113, which operates to substantially center
the lock plug
I 13 within the opening in the housing 30. In addition, means are provided
between lock
plug sleeve 113 and lock plug I 1 I to provide locked and unlocked conditions
of the latch
assembly 10. In this embodiment, the lock plug sleeve 113 includes a groove
150 on its
inner surface that cooperates with the wafers of lock plug I 11 in order to
provide the
locked and unlocked conditions of the latch assembly 10. In particular, in
this
embodiment, the wafers of lock plug 111 are extended when key 119 is removed,
and in
this manner, rotation of lock plug 1 I 1 is prevented when the wafers are
received in the
groove 150 of sleeve 113. The wafers of lock plug 111 are retracted away from
the
groove 150 in lock plug sleeve 113 by insertion of key 119, which allows for
subsequent
rotation of lock plug 111 relative to lock plug sleeve 113.
Positioned coaxially between the hosing 30 and the sleeve-like cam 20 is a
motion
control sleeve 40 having a pair of motion control slots. Each motion control
slot has an
axial slot portion 41 and a circumferencial slot portion 42. Each of the axial
portions 41
extends in a direction parallel to the longitudinal axis of the housing 30,
and each of the
circumferencial slot portions 42 extends along a length of arc of a circle
formed in a plane
perpendicular to the longitudinal axis of the housing 30, with the latch
assembly 10 in the
2 0 fully assembled configuration. In the present embodiment, the motion
control slots are
spaced 180° from one another. The end of each axial slot portion 41,
located distally from
the first end of the housing 30, connects with one end of a respective one of
the
circumferencial slots 42. The latch assembly 10 firrther includes means for
substantially
preventing rotation of the motion control sleeve 40 relative to housing 30. In
this
2 5 embodiment, the sleeve 40 includes two notches 152 at its lower end and
which rest on
two tabs 160 on the bottom interior of housing 30. The latch assembly 10
further includes
means between the motion control sleeve 40 and lock plug sleeve 113 for
substantially
preventing rotation of lock plug sleeve 113 relative to housing 30. In this
embodiment, the
sleeve 40 includes a pair of notches 44 at its upper end and which receive
ears 140 which
3 0 project axially from the distal end of lock plug sleeve 113. The fixed
motion control
sleeve 40 may also be provided integral with the housing 30 being formed
directly within
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or extending from an inner surface of the housing 30. The slot portions 41 and
42 in the
motion-control sleeve 40 function respectively as rotational motion-control
slots and as
axial motion-control slots.
Shaft SO is elongated and projects outward from the second end of the housing
30
by passing through the central hole at the second end 32 of housing 30. The
shaft SO is
supported such that the longitudinal axis of the shaft SO coincides with the
longitudinal
axes of the housing 30, the motion-control sleeve 40, and the cam 20. At least
the
majority of the portion of the shaft SO which lies outside the housing 30, is
provided with
interrupted screw threads. The screw threads of the shaft SO are interrupted
by a pair of
flats machined on either side of at least the threaded portion of the shaft
S0. The threaded
portion of the shaft SO fits through a hole in one end of the pawl 70. The
hole in the end
of the pawl 70 has flat sides which match the flats on either side of the
shaft S0. Thus,
relative rotation between the pawl 70 and the shaft SO is prevented, and the
pawl 70 and
the shaft SO rotate about the longitudinal axis of the shaft SO as a unit. The
interrupted
screw threads on the shaft SO are engaged by the mounting nuts 71 in order to
secure the
pawl 70 in place at a desired location along the length of the threaded
portion of the shaft
S0.
The relative positions of the motion-control sleeve 40 and cam 20 could be
reversed. That is, motion-control sleeve 40 could be inside of cam 20 rather
than outside
2 0 as shown. Mounted on the shaft SO is the cross-pin 60 which projects
laterally from
opposite sides of the shaft SO and functions as both a cam follower and as a
motion-
control pin. Cross-pin 60 cooperates with the cam 20 and the motion control
sleeve 40 to
control whether, in response to rotation of the lock plug I 11, the shaft SO
and pawl 70
will move only axially or only rotationally. This is determined by whether the
opposite
2 5 ends of pin 60 are positioned through the axial slot portions 41 or
through the
circumferencial slot portions 42.
The housing 30 is mounted on the closure member by retaining means which, in
the present embodiment, is comprised of a washer and a mounting nut engaging
the
threads on the outer surface of housing 30. In the present embodiment, the
housing 30 is
3 0 installed in a closure member by positioning the latch assembly 10 such
that the housing
30 extends through an aperture passing through the closure member. The latch
assembly
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is installed such that the first end of the housing 30 is accessible by a user
for insertion
of the key 119. The installation of the latch assembly I 0 is most easily
accomplished when
the pawl 70 is not mounted on the shaft 50, so that the shaft 50 can be
inserted first
through the aperture in the closure member. The pawl 70 can then be mounted to
the
5 shaft 50 after the housing 30 is positioned to extend through the aperture
formed in the
closure member, however, this sequence of steps for the installation of the
latch assembly
10 is not a requirement. The housing 30 is then secured within the aperture of
the closure
member by the mounting nut and, if desired, also the washer.
In the present embodiment, the components of the latch assembly 10 are
10 preferably comprised of metal and metal alloy materials, however, other
suitable materials
can also be used where desired. In addition, in the present embodiment, the
closure
member can be comprised of any suitable materials, such as wood or metal, and
can be of
varying thickness.
The operation of the latch when installed as part of an assembly including a
closure member, will now be described. When lock plug 111 is rotated, as by
the key
119, the sleeve-like cam 20 will be driven to rotate in the same direction as
the lock plug
1 I 1. When cam 20 is rotated, cross pin 60 is moved, but whether the movement
is axial or
rotational is dependent upon whether the ends of pin 60 are in the axial slot
portions or in
the circumferencial slot portions of the motion-control sleeve 40.
2 0 When in the latched position, lock plug 111 is at its fully clockwise
position, and
the two opposite ends of cross pin 60 are positioned through the axial slot
portions 41 of
the motion-control sleeve 40, near the ends of the axial slot portions 41
which are closest
to the first end of the housing 30. In addition, the portions of the cross pin
60 projecting
from either side of the shaft 50, simultaneously engage the cam slots 25 of
the cam 20. At
2 S the extreme of the clockwise rotation of the lock plug 111, the projecting
portions of the
cross pin 60 are positioned nearest to the ends of the cam slots 25 which are
closest to the
proximal end of the cam 20. The pitch of each of the cam slots 25 is such that
the axial
distance, i.e. the distance measured in a direction parallel to the
longitudinal axis of the
cam 20, between a location along the cam slot 25 and the proximal end of the
cam 20
3 0 increases in the clockwise direction, beginning at the end of the cam slot
nearest the
proximal end of the cam 20.
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To unlatch the closure member from, for example, the cabinet frame, lock plug
111 is turned in a counterclockwise direction. When this is done, lock plug
111 and cam
20 rotate as a unit. The cross pin 60 cannot move rotationally because its
opposite ends
are within the axial slot portions 41 of the stationary motion-control sleeve
40. As a
result, when cam 20 is rotated counterclockwise, the opposite ends of pin 60
follow the
opposed cam slots 25, and as a result, pin 60, and hence also shaft 50 and
latch pawl 70,
will move away from the first end of the housing 30 in a direction parallel to
the
longitudinal axis of the shaft 50. The axial movement of the shaft 50 and the
pawl 70,
away from the first end of the housing 30 and away from the frame of the
closure
member, continues until the ends of the pin 60 reach the circumferencial slot
portions 42.
After lock plug 111 and cam 20 have been rotated as a unit through
approximately 120 degrees, cross pin 60 has moved axially away from the
proximal end of
the motion control sleeve 40, and is now aligned with the opposed
circumferencial slot
portions 42. Further rotation of lock plug 111 and cam 20 now causes
rotational
movement of cross pin 60, shaft 50 and pawl 70, as the ends of pin 60 move
along the
opposed circuferencial slot portions 42. In this manner, pawl 70 is moved out
of
alignment with the fi-ame member, and after approximately 60 degrees of
rotation, the
closure member or door is firlly unlatched. Lock plug 111 has now been rotated
approximately 180° relative to its fially latched position.
2 0 The latching action is simply the reverse of the unlatching action just
described.
On latching, as lock plug 111 is funned clockwise, the opposite ends of cross
pin 60 move
in the clockwise direction along the circumferencial slot portions 42 and the
shaft 50
rotates in the clockwise direction about its longitudinal axis. Then the cross
pin 60
translates axially toward the proximal end of the motion control sleeve 40,
when the cross
2 5 pin 60 reaches the axial slot portions 41. These sequential motions are
caused by the walls
22 of the cam slots 25, which urge the ends of the cross pin 60 along the
circumferential
slot portions 42 in the clockwise direction, until the ends of the cross pin
60 abut against
the edge of the axial slot portions 41. Thereafter, walls 22 of the cam slots
25 urge the
ends of the cross pin 60 axially toward the proximal end of the motion control
sleeve 40
3 0 along the axial slot portions 41. Thus, cam 20 and the motion-control
sleeve 40
cooperatively cause the rotational and axial motions of the shaft 50 to take
place in
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sequence, in response to the rotational motion of the lock plug 1 I I in the
latching or
clockwise direction, in one continuous motion.
The new latch assembly has been described as mounted on a movable door. This
is the preferred location. However, a latch embodying the basic concept of the
present
5 invention could be mounted on the fixed cabinet rather than on the door. In
such case, the
shaft and latch pawl would be moved rotationally to engage a keeper mounted on
the
inside of the door and then axially away from the first end of the housing 30
to push the
door to the tightly closed position. This is the reverse of the axial motion
used to pull the
door tightly shut when the latch is mounted on the door. When the latch I O is
used in this
10 mode, the closure member. will be latched in the counter clockwise
direction and unlatched
in the clockwise direction. The latching and unlatching directions of the
latch 10 can be
reversed by simply reversing the pitch of the cam slots 25 and the direction
in which the
axial slot portions 4I extend relative to the circumferencial slot portions
42. Clockwise
and counter clockwise directions as used herein refer to the direction of
rotation as
perceived by a viewer facing the key hole of the lock plug 11 I .
It will be recognized by those skilled in the art that changes may be made by
the
above-described embodiments of the invention without departing from the broad
inventive
concept thereof. It is understood, therefore, that this invention is not
limited to the
particular embodiments disclosed, but it is intended to cover all
modifications which are
2 0 within the scope and spirit of the invention as defined by the appended
claims.
INDUSTRIAL APPLICABILITY
The present invention is directed to a latch mechanism having wide ranging
2 5 industrial applicability where ever there is a need to releasably secure a
first closure
member, such as a door, panel, or the like, relative to a second closure
member such as a
door, a panel, a compartment, a cabinet, a container, a frame, or the like.
