Note: Descriptions are shown in the official language in which they were submitted.
DOOR CLOSER
In the general installation of door closers, there
is a panel which is rnovable with respect to its frame,
Sometimes this is a pure sliding movement, but normally
it is a hinged or pivoting movement. The closer is a
spring-actuated device connected to the panel and to
the frame for impelling the panel into its closed, and
usually latched, position. A spring alone produces too
erratic an action, and so there is also normally included
a hydraulic dashpot operating through bleed apertures
which are variable so that portions of the door panel
closure movement can be damped and thus produce a proper
and acceptable panel operation.
~hile under many circumstances such an arrangement
is in itself entirely satisEactory, it is desirable to
provide a door closer construction in which the closure
mechanism includes a way of permitting extra force on
the door panel to be effective in closing the door in
at least some portion of its closing movement.
The present invention accordingly provides a door
closer for use with a door frame and a door panel movable
through a defined path relative to said frame comprising
a cylinder body having a chamber and a cylinder, a head
closing one end of said cylinder, a piston reciprocable
in said cylinder, means interconnecting said piston and
said panel for moving said piston in said cylinder toward
and away from said head in accordance with the movemen~
of said panel relative to said door frame, a spring for
urging said piston toward said head, a duct for allowing
fluid to bypass said piston and flow from said cylinder
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into said chamber, a check valve in said duct, means in
said body defining a passage shunting said piston in all
positions thereof and extending between said cylinder and -
said chamber, a throttle valve in said passage near said
head, a bore in said body extending between and open to
said passage and open to a portion of said cylinder swept
by said piston, means in said body defining a bypass chan-
nel open to said passage and ~o said cylinder, a tube in
said bypass channel and open at one end to said cylinder,
means closing the other end of said tube, a stem disposed
concentrically within said tube, means defining an aper-
ture in a wall of said tube affording access between said
bypass channel and the interior of said tube, and a sleeve
in said tube and surrounding said stem and adapted when
unstressed to overlie said aperture and adapted under
pressure in said aperture to move radially and axially of
said stem to afford communication between said aperture
and said cylinder.
In the drawings:
Figure 1 is a diagrammatic or cahematic view from
above showing the interrelationship of a door frame, a
door panel, and the closer mechanism of the present in-
vention,
Figure 2 is a cross-section on an axial plane through
a door closer mechanism constructed in accordance with the
invention;
Figure 3 is a cross-section to an enlarged scale of
a latch speed valve, the section being taken on the line
3-3 of Figure 2 and certain parts being rotated for
clarity of illustration; and
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Figure 4 is a cross-sectional view of a bypass valve,
the plane oE section being indicated by the line 4-4 of
Figure 2, with certain parts beinq rotated for clarity of
disclosure.
While the door closer of the invention is capable of
installation under widely different circumstances and on
widely different door constructions, it has successfully
been incorporated in a standard installation as shown
herein. In such an installation there is a frame 6.
This most often is a wall having an opening 7 therein
serving as a door opening and in connection with which
there is provided a door panel 8 connection to the wall
by hinges 9 or the like, so that the door panel can be
swung through a relatively large arc for opening and
closing purposes. Pursuant to the present invention,
that arc is subdivided into two portions, one of which, a
portion 11 near closure, is relatively small in angular
extent, and the remaining portion 12, away from closure
and toward full opening, is relatively greatD A latching
lock 10 is usually provided in the standard way.
While the door closer mechanism can be variously
installed, it is currently illustrated as shown with a
cylinder body 16 mounted on a door panel 8 and a toggle
linkage 17 connecting the mechanism within the body with
the door frame 6, so that a shaft 18 carried in the body
15 is rotated in accordance with the relative angular
movement between the frame 6 and the panel 8. The shaft
18 is appropriately journalled in the body 16 and between
its ends carries a gear 19 disposed in a chamber 21 in
the body and through which the shaft 18 passes. The gear
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19 meshes with a rack 22 on a rack bar 23 jointing a pis-
ton 24 having a passage 25 therethrough and a piston 26.
The pistons are spaced apart, but both engage the interior
surface of a cylinder 27 formed within the body 16 and
S extending therethrough. The piston 24 is in contact with
a compression spring 28 held in position by an end plug
29 screwed into one end of the body and closing that end
of the cylinder. The other piston 26 is utilized in the
control of the structure and reciprocates in the cylinder
27, which is closed at the other end by a head 31.
As part of the means for controlling the motion of
the closer and of the door panel, the interior o~ the
closer is filled with an appropriate hydraulic fluid,
such as a lubricating oil. Movement of the piston 26
causes displacement of the oil, and for that reason and
for one direction of motion the piston 26 is particularly
provided with a duct 34 in which is seated a check valve
36. During motion of the piston 26 from right to left
in Figure 2, the check valve is closed, but piston motion
from left to right in Figure 2 is accompanied by unseat-
ing of the valve ball 36, and there is flow of oil from
the chamber 21 into the closer volume 37. This is a
variable volume defined by the cylinder wall itself and
by the piston 26 and the head 31. Thus both the chamber
21 and the cylinder 37 are variable in volume, depending
in large part upon the movement of the piston 2~.
In accordance with the invention, not only is there
a provision for liquid passage through the piston 26 via
the duct 34, but there is also a comparable or paralllel
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flow path. Formed in the body 16 is a passage 38 extend-
ing parallel to the cylinder and at its head end merging
with a cross bore 39 in the body and opening into the
cy]inder 37 near the head end t~ereof. In the bore 39
there is a throttle or regulating or latch speed valve
~1. This is a body sealed in the cross bore by an 0-ring
44 and engaging the body by means of threads ~6, so that
the axial position of the mechanism can be set. The
lower end of the regulator 41 is tapered in at l~ast
one portion as at 47 and allows hydraulic flow between
the cylinder volume 37 and the cross passage 38 in a
regulated amount, depending upon the area of the portion
47. Thus, liquid can flow between the cylinder and the
passage 38 in both directions as regulated by the area
of the opening provided by the tapered portion 47.
There is an additional flow passage. In the body
16 there is a bore 48 extending between the cylinder 37
and the passage 38. The bore pierces the cylinder wall
in an axial location that is well within the path of
travel of the piston. Thus, for part of the piston travel
the cylinder 37 is open through the bore 48 to the pas-
sage 38, whereas in the final movement of the piston in
the vicinity of and .oward the head 31, the piston is
beyond the bore 48 and the bore cannot be effective to
afford communication at that time between th2 cylinder
and the passage 38. The piston preferably is contoured
to afford the desired flow characteristics.
Flow through the passage 38 is controlled by a by
pass valve 49 as shown in Figures 2 and 4. The bypass
valve is disposed in a passage 51 in the body 16. This
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passage extends from the exterior of the body into the
chamber 21 and is parallel to the bore in which the
valve 41 is disposed. Included in the valve 49 is not
only an o~ltside tube 53 threaded into the closer body,
but within such tube there is provided an elastomeric
sleeve 54 having a flange 56. The sleeve in turn
surrounds a central stem 57 of cylindrical form having
a disc end 58. This is contacted and held in position
by a plug 59 pressed into and so held in position in
the body 16. An O-ring 61 prevents leakage between the
body 53 and the outside. The passage 33 opens into a
volume 62 surrounding the inward portion of the member
49. Not only is the sleeve 53 provided with an axial
opening 64 communicating with the chamber 21, but like-
wise the wall is pierced by an aperture 66 open to thechamber 62 and so communicating with the passage 38.
In the operation of this device, the parts can be
considered to start out in the relationship shown in
Figure 2, corresponding to the door panel 8 being in an
open location. The force of the then-compressed spring
28 urges the rack bar 23 toward the left in Figure 2 or
toward "closed" position. Such movement causes the rack
22 to exert a corresponding rotary force on the gear 19
and thus through the linkage 17 tends to move the panel
8 toward closed position. This movement of the rack bar
23 likewise correspondingly translates the piston 26 to
$he left in Figure 2. The piston motion tends to dis-
lodge liquid from the cylinder volume 37, but there is
no longer a passageway through the duct 34 since this
direction of motion i5 accompanied by a seated position
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of the check valve 36. The trapped cylinder liquid can-
not flow through the throttle valve 41 or throuyh the
passage 47 into the passage 38, as the pressure in the
chamber 3g and the chamber 37 is the same. Thus there
is no imbalance which would cause the fluid to move.
That means that the speed of movement of the closer
toward the left is not affected by the throttle valve
41 when the piston 26 is in the initial portion of the
closing movement.
But while the piston 26 is only in the initial
portion of its closing movement, there is liquid flow
through the bore ~8 into the passage 38, and this passage
38 is substantially unrestricted and is generally made
somewhat larger than the passageway 47. That means that
a large part of the flow out of the cylinder 37 during
initial closing movement is through the bore 48 into the
passage 38. Hence, during this portion of the piston
movement there is no restriction on the rate of movement
of the piston, at least by the passage 47 and the passage
48. Regulation by the throttle valve 41 is therefore of
no consequence during the initial closing movement of the
piston 26, but in the final closing movement, the piston
26 overrides the bore 48 and the flow is throttled by
the portion 47, a substantial restriction.
Flow from the passage 38 back to the chamber 21 is
particularly regulated by the bypass valve 49 as shown
in Figure 4. Flow is into the valve chamber 62 from the
passage 38 and under ordinary circumstances is merely
through a tube slot 71 into the chamber 37. This is a
relatively limited amount. However~ special means are
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provided for operation at an increased pressure to bypass
more Çluid. For that reason, the aperture 66 through one
wall of the tube 53 allows fluid pressure to act against
the elastomeric sleeve 54. Thus, when the flow tends
to be sufficient to cause a pressure increase, that in-
creased pressure displaces or deforms the elastomeric
sleeve away from the aperture 66 and toward the stem 57
and allows liquid to flow parallel to the opening 71 and
through a channel 74 into the chamber 21. When the pres-
sure in the passageway 3~ drops, then the opening 66 andthe channel 74 are closed and there is a resumption of
its normal shape by the elastomeric sleeve 54. Flow is
then confined to the passage 71.
It occurs in some installations that the panel 8 is
urged toward closed position by a potentially excessive
manual force. When that occurs within the range 12, the
piston 26 has not quite reached a position to overlie
and block the bore 48. The extra force simply puts
extra pressure on the liquid, which then causes the
elastomeric sleeve 54 to deform, as shown in Figure 4, to
allow faster closing of the panel than the usual closer
mechanism itself would permit. However, as soon as the
panel moves in the range 11 near the latching position,
the piston 26 by that time has overridden the bore 48.
No longer can the liquid pass through that bore 48 and
be governed solely by the setting of the bypass valve 49.
Rather, the bore 48, having been traversed or overridden,
leaves the throttle valve 41 as the only means of escape
of liquid from the then-diminished volume cylinder.
Under those conditions, the throttle valve 41, having
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a set adjustment or minimum open position, definitely
limits the amount of flow area for the discharging
]iquid and governs to a set rate the final closing move-
ment of the panel despite a large exterior, manual force
imposed thereon. In this way the latching mechanism is
well protected against a slam or undue overloading.
Thus, there is provided within the normal compass
or frame of a door closer a mechanism which permits rela-
tively free use of additional force during a large part
of the closing path of the door panel but always ensures
that the final closing and latching movement of the door
panel is limited to a definite maximum amount~
