Note: Descriptions are shown in the official language in which they were submitted.
LIFT-OFF TYPE HINGE
TECHNICAL FIELD
This invention relates generally to door hinges, and more particularly to
hinges used for
commercial refrigerator and freezer doors.
BACKGROUND OF INVENTION
Walk-in cold rooms, such as walk-in coolers, freezers, or other refrigerated
environments,
are common in various industries, including supermarkets and grocery stores,
commercial kitchens,
and other food service facilities. They typically have one or more access
doors for entry and exit.
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These doors are heavy and thus a common problem that may occur over time is
door
sag, which may cause the door not to open freely as it drags against the
underlying floor or
be properly locked or sealed as it does not fully close. The sag is caused by
hinge wear,
structural shifting due to temnerature cycling, impacts, abuse, poor design of
the door and
frame, or the hinges shifting on the mounting screws. Sag is difficult to
overcome without
extensive repair work, such as the removal and remounting of the hinges or the
replacement
of the door and frame. For the replacement, adjustment or cleaning of the
hinge the NSF
prefers that the hinge be a "lift-off' type to allow the door and the
enclosure to be cleaned
by lifting it off the hinges and hosing down the door assembly.
to A problem associated with these "lift-oft" type hinges is that the
hinge spring is
designed to move the cam past the point of door closure to ensure a complete
closing of the
door, this may be referred to as an over-closure angle between the hinge strap
and hinge
flange. As a result of the over-closure of the earn when the door is taken off
the hinge, the
subsequent replacement of the door upon the hinge flange does not always
result in the
15 proper alignment of the hinge strap upon the hinge flange. This
problem can result in the
poor closure function of the hinge, the misalignment of the hinge components,
ancUor
damage to the hinge.
Accordingly, there is a need in the art for a hinge that will allow for the
door to be
lifted off easily, which does not promote door sag, which allows small
adjustments to the
20 hinge, and which properly aligns the hinge components when
disassembled and subsequently
reassembled. It is to the provision of such therefore that the present
invention is primarily
directed.
SUMMARY OF THE INVENTION
In a preferred form of the invention a hinge comprises a mounting flange
assembly having
a cam and a rotating cam follower configured to mate with the cam. The cam
follower has an
exterior surface and a longitudinally extending alignment groove extending
inwardly from the
exterior surface. The hinge also has a strap assembly pivotally coupled to the
mounting flange
assembly. The strap assembly includes a strap having at least one strap
mounting hole and a
coupling end having a longitudinally extending channel therein configured to
receive at least a
portion of the mounting flange cam follower. The channel includes a
longitudinally and inwardly
extending alignment groove of the cam follower. With this construction, the
proper alignment
between the cam follower and the strap assembly may only occur when the
alignment tongue aligns
with and is received within the alignment groove.
In a broad aspect, the present invention pertains to a hinge for use with a
refrigerator door,
designed to rise relative to a surrounding door jamb when moved from a closed
position to an open
position. The hinge comprises a mounting flange assembly adapted to be mounted
to the jamb of
a refrigerator door, the mounting flange assembly having a cam and a rotating
cam follower
configured to mate with the cam, and be moved longitudinally by relative
rotational movement
between the cam and the cam follower. The cam follower has an exterior surface
and a
longitudinally extending vertical, alignment groove extending inwardly from
the exterior surface.
A strap assembly is adapted to be mounted to a refrigerator door, the strap
assembly being pivotally
coupled to the mounting flange assembly and vertically movable, relative to
the mounting flange
assembly, through relative rotation between the cam of the mounting flange and
the cam follower
coupled to the strap assembly. The strap assembly includes a strap having at
least one strap
mounting hole and a coupling end having a longitudinally extending vertical
channel therein,
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configured to receive at least a portion of the mounting flange cam follower.
The vertical channel
includes a longitudinal, vertical aligmnent tongue extending into the channel
and configured to be
received within the longitudinally extending vertical alignment groove of the
cam follower. The
proper alignment between the cam follower and the strap assembly only occurs
when the vertical
alignment tongue aligns with and is received within the vertical alignment
groove.
In a further aspect, the present invention provides a hinge for use with a
refrigerator door,
designed to rise relative to a surrounding door jamb when moved from a closed
position to an open
position. The hinge comprises a mounting flange assembly mountable to a
refrigerator doorjamb,
having a cam and a generally vertically oriented cam follower configured to
engage the cam and
be moved vertically by relative rotational movement between the cam and the
cam follower. The
cam follower has at least a first portion having a select regular polygon
exterior configuration
having a generally vertically extending exterior alignment groove. There is a
strap assembly
mountable to a refrigerator door and pivotally coupled to the mounting flange
assembly and vertical
movement, relative to the mounting flange assembly, through relative rotation
between the cam of
the mounting flange and the cam follower coupled to the strap assembly. The
strap assembly
includes a strap having a vertical channel therein configured to receive at
least a portion of the cam
follower first portion, and the vertical channel includes a longitudinally
extending vertical
alignment tongue configured to be received within the vertical alignment
groove of the cam
follower. The proper alignment between the cam follower and the strap only
occurs when the
vertical alignment tongue aligns with and is received within the vertical
alignment groove.
In a still further aspect, the present invention provides a hinge for use with
a refrigerator
door, designed to rise relative to a surrounding door jamb when moved from a
closed position to
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an open position. The hinge comprises amounting flange assembly mountable to a
refrigerator
door jamb, and a cam assembly mountable to a refrigerator door and coupled to
the mounting
flange. The cam assembly has an exterior surface and generally vertical
alignment groove
extending inwardly from the exterior surface, and has a cam and a cam follower
configured to rotate
relative to the cam for cammed vertical movement of the cam follower. A cam
assembly is
mountable to a refrigerator door and is pivotally coupled to the mounting
flange assembly, for
vertical movement relative to the mounting flange assembly through relative
rotation of the cam
coupled to the mounting flange and the cam follower coupled to the strap
assembly. The strap
assembly includes a strap having a vertical channel therein configured to
receive at least a portion
of the cam assembly. The vertical channel includes a longitudinally extending
vertical alignment
tongue configured to be received within the vertical alignment groove of the
cam follower. The
proper alignment between the mounting flange and the strap assembly only
occurs through the
orientation of the vertical alignment tongue within the vertical alignment
groove.
BRIEF DESCRIPTION OF DRAWINGS
Fig. 1 is a front view of an anti-sag hinge embodying principles of the
invention in a
preferred form.
Fig. 2 is atop view of the anti-sag hinge of Fig. 1, shown in partial cross-
section.
Fig. 3 is a perspective view of a portion of the anti-sag hinge of Fig. 1.
Fig. 4 is an exploded view of the anti-sag hinge of Fig. I.
Fig. 5 is a cross-sectional view of a bushing of the anti-sag hinge of Fig. I.
Fig. 6 is a perspective view of the cam follower of the anti-sag hinge of Fig.
1.
Fig. 7 is a perspective view of the spacer of the anti-sag hinge of Fig. 1.
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=
DETAILED DESCRIPTION
With reference next to the drawings, there is shown a lift-off type anti-sag
hinge 10
according to the present invention. The hinge 10 includes a mounting flange
assembly 12
pivotally coupled to a strap assembly 15. It is to be appreciated that the
hinge 10 shown in
the drawings is configured for use with a walk-in refrigerator or freezer
door. The jamb and
doors are well-known in the art and need not be disclosed further herein. It
is to be further
appreciated that the hinge 10, either alone or in combination with another
hinge in
accordance with the present invention, support a door (not shown) in the usual
manner.
The mounting flange assembly 12 includes a metal mounting plate 16 having four
mounting holes 17 therethrough adapted to receiving unshown mounting bolts or
screws, and
a metal lower hinge flange 18 extending from the mounting plate 16. As used
throughout
the entire disclosure herein, the terms screw and bolt are used
interchangeably. The lower
hinge flange 18 includes a cam recess 19 configured to receive a cam assembly
which has
an internally mounted cam 20 and cam follower 40 which enables the hinge to be
a riser type
hinge, although this is merely an option of the present invention. The cam 20
includes a dual
sloped camming surface 21. The cam 20 and later described cam follower 40 are
preferably
made of a smooth, low-frictional plastic material such as nylon. The lower
hinge flange 18
also includes a shoulder bolt hole 22 therethrough in which is mounted a
shoulder bolt or rod
25.
The strap assembly 15 includes a metal elongated strap 31 extending from a
cylinder
portion 32. The term cylinder portion 32 is meant to describe the enlarged
casing located at
the end of the strap and the encased bearings, spring, and cam described in
more detail
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hereinafter. The term cylinder portion is not intended to be limited to a
cylinder shape, as
this portion or parts of this portion may be of many known shapes and are not
necessarily
cylindrical in shape.
The cylindrical portion 32 includes a coupling end 34 with a vertically
extending
octagonal channel 35 therethrough. The octagonal channel 35 includes a
generally vertically
extending alignment ridge or tongue 36 extending longitudinally along the
channel 35 and
a centrally positioned, horizontally oriented, annular ridge 37 which
generally bisects the
channel 35. A cap 38 is pressed into and seals the top opening of the channel
35. The
cylindrical portion 32 also houses the elongated cam follower 40 having a
lower cam
follower portion 41 and an upper cam follower portion 42. The lower cam
follower portion
41 has an octagonal exterior surface 43 terminating at a circumferential ledge
or shoulder 44
positioned to abut and bear against the centrally positioned annular ridge 37
of the coupling
end 34. It should be noted that the coupling end octagonal channel 35 is
longitudinally
symmetric about the centrally positioned annular ridge 37 so that the cam
follower 40 may
be positioned in either end, thereby making it reversible (either left hand or
right hand door
configurable) so that the cam follower may fit in the octagonal channel 35
from either open
end. The lower cam follower portion 41 also has an interior surface 46 with a
cam following
surface 47 configured to mesh or mate with the cam camming surface 21. The cam
following surface 47 includes a low point or low point area 48 flanked on
either side by
symmetrical incline surfaces which terminate at a common dwell surface. The
symmetry
allows the cam follower to rise with rotation in either direction so that the
hinge may be
mounted to both right hand and left hand opening doors. The lower cam follower
portion
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41 also has a longitudinally extending slot or groove 53 configured to receive
the coupling
end alignment tongue 36. The groove 53 has a camber 54 in the ledge 44
(cambered
entrance) at its top end which aids in initially guiding the tongue 36 into
the groove as the
strap assembly is coupled with the mounting flange assembly 12 with the cam
follower being
inserted into the mounting end octagonal channel 35. The groove 53 is aligned
along the
exterior surface directly opposite the low point 48, so that the groove 53
extends into or
corresponds to the longest portion of the carnming surface to allow for the
greatest degree
of strength or minimizing the weakening of component due to the absence of
material created
by the groove 53.
The upper cam follower portion 42 is generally cylindrical with a round
exterior
surface 55 and a round interior surface 56 defining an interior channel 57
commencing at an
interior floor 58. A bolt or rod hole 59 passes through the center of the cam
follower in
which resides the shoulder rod 25 so that the cam follower 40 may rotate or
pivot about the
shoulder rod and relative to the underlying cam 20.
The strap assembly 15 also includes a compression spring 62 positioned
concentrically about the shoulder rod 25 and within cam follower interior
channel 56. A
bushing 63 and washer 64, positioned on top of the bushing 63, are also
positioned
concentrically about the shoulder rod 25 and within the cam follower interior
channel 56.
The bushing 63 has a peripheral flange 65 with an annular bottom recess 66
configured to
receive a topmost portion of the compression spring 62, which enables the
spring 62 to be
maintained tightly in position while still allowing lateral room for the
spring to expand
during spring compression under load, i.e., with the spring under no load
there is room
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between the spring and the interior surface 56 which allows the spring to
laterally expand
when it is vertically compressed and therefore laterally expanded under a
load. The top of
the shoulder rod 25 is blunted or deformed to prevent the removal of the
washer 64 and
thereby the bushing 63 and spring 62. The compression of the spring 62 biases
the cam
follower 40 to its lowermost position, which will correlate with the closed
position of the
refrigerator door or an over-closure position past the closed position of the
refrigerator door,
and a such the hinge shown in the drawings is a self-closing type hinge.
The strap 31 includes a large interior well or recess 68 having four elongated
mounting holes 69, an adjustment screw flange, holder or boss 70 having a
screw hole or
passageway 71 therein, an upper guide 72 and a lower guide 73. The recess 68
is defined by
the sidewalls 74 of the strap 31 which extend to the most outboard portion of
the hinge, i.e.,
a peripheral sidewall 74 which extends outwardly from the underlying door so
as to make
initial contact with any structure colliding with or impacting upon the hinge.
The adjustment
screw boss passageway 71 preferably is U-shaped so as to have an open top
configuration.
The strap 31 also includes a moveable adjustment bracket 77 mounted for
lateral
movement relative to the underlying strap 31. The vertical movement of the
adjustment
bracket 77 is limited by the upper guide 72 and lower guide 73. The adjustment
bracket 77
also includes an adjustment screw mounting flange 78 having a threaded screw
hole 79
therein in which is threadably mounted an adjustment screw 80. The adjustment
screw 80
has a head 81, a bearing flange 82, a neck 83 extending between the head 81
and bearing
flange 82, and an externally threaded shaft 84 which is threaded into mounting
flange screw
hole 79. A removable spacer 86 is removably mounted to the adjustment screw
80. The
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spacer 86 has a U-shaped gripping portion 87 which is snap fitted onto a neck
portion of the
threaded shaft 84 between the bearing flange 82 and the adjustment bracket
screw flange 78.
Lastly, the adjustment bracket 77 includes four mounting holes 88 extending
therethrough
and generally in alignment with strap elongated mounting holes 69. A flexible
bumper or
cover 90 is configured to fit snugly into the top end of the strap recess 68
to protect and seal
the interior of the strap assembly, the bumper may include tabs which fit
within
corresponding tab holes or grooves in the strap.
In use, the hinge 10 is mounted to the refrigerator or freezer door in the
conventional
manner as is well known in the art. The mounting plate 16 is secured to the
jamb by the use
of screws (not shown) that extend through the mounting plate mounting holes 17
and into
the jamb. A conventional walk-in refrigerator or freezer door is similarly
secured to the
hinge 10 by four screws (not shown) that extend through the four mounting
holes 88 of the
strap assembly adjustment bracket 77 and through the four elongated mounting
holes 69 of
the strap 31. The removable spacer 86 is initially positioned so that the
adjustment bracket
mounting holes 88 are aligned with the strap mounting holes 69. Once the
flange assembly
mounting screws are secured and the strap assembly mounting screws are
partially secured
but not finally tightened, final adjustment of the adjustment bracket may
occur to level the
door.
To adjust the bracket, the removable spacer 86 is removed and the adjustment
screw
/c) 80 is rotatably threaded into the threaded hole 79 of the screw
adjustment flange 78 to cause
relative movement between the adjustment bracket 77 and the underlying strap
31. This
relative movement causes the movement of the door relative to the stationary
jamb, as the
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elongated holes 69 allow relative movement of mounting screws and adjustment
bracket.
The movement of the door enables the door to be properly aligned. The mounting
screws
are then fully tightened into the door to prevent further movement of the
strap 31. Moreover,
should the door sag over time, the mounting screws are slightly loosened and
the adjustment
screw is merely threaded to once again cause movement of the door to a
properly aligned
position, as previously described.
The rotation of the adjustment screw 80 in one direction (clockwise) causes
the
threaded screw 80 to be threaded further into the screw flange 78 of the
adjustment bracket
77, thereby causing the adjustment bracket 77 to move towards the boss 70. The
rotation
of the threaded screw 80 in this direction causes the screw head 81 to bear
against the boss
70 to force the lateral movement. The rotation of the adjustment screw 80 in
the other
direction (counter-clockwise) causes the threaded screw 80 to be threaded
further out of the
adjustment bracket flange 78, thereby causing the adjustment bracket 77 to
move in a
direction away from the boss 70. The rotation of the threaded screw 80 in this
direction
causes the screw bearing flange 82 to bear against the boss 70 to force the
lateral movement
in a direction away from the boss 70. As such, the bolt is allowed to rotate
yet is prevented
from moving laterally along the longitudinal axis of the bolt by the contact
between the bolt
and the boss due to the bolt head and bearing flange bearing upon the boss.
It should be understood that the present invention is an improvement over the
prior
art shown in U.S. Patent No. 7,870,642 as the threaded portion in which the
adjustment
screw is threaded into resides in the removable adjustment plate. This allows
the
manufacturing of the threads in the mounting hole to occur in a simple manner,
as oppose
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to the prior art which required the threading process to occur on the large,
heavy flange of
the strap itself, thus complicating the manufacturing process of the hinge and
causing a great
deal of problems if the threads were not properly formed. Furthermore, if the
threads become
stripped or damaged only the adjustment bracket needs to be replaced rather
than the entire
hinge strap.
It should also be understood that the open channel or passageway 71 of the
boss
allows for the ease of positioning the adjustment bracket by simply dropping
the adjustment
screw neck 83 into the boss wherein the spacer is utilized to maintain the
position of the
adjustment screw.
It should be understood that the lower portion 41 of the cam follower is not
required
to be hexagonal in shape and may be of any shaped which aids in preventing
relative rotation
between the cam follower and its corresponding channel, i.e., it may be oval,
any polygonal
shape, or any other non-round shape. Preferably, the cam follower has regular
polygon
exterior configuration wherein all sides and angles are equal, such as the
octagonal shape
shown in the preferred embodiment.
It should be understood that the terms cam and cam follower may be used
interchangeably, as each simply includes a sloping surface configured to ride
upon the other's
sloping surface.
While this invention has been described in detail with particular reference to
the
preferred embodiments thereof and the best mode of practicing same, it will be
understood
that variations and modifications can be effected within the spirit and scope
of the invention
as described herein above and as set forth in the appended claims.
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