Improvements in Door Checks.
Year: 1892

page_text: Date of Application, 6th Aug., 1892-Accepted, 24th Sept., 1892
COMPLETE SPECIFICATION.
Improvements in Door Checks.
I, JOSEPH KEENE, of 275 S. Clark Street, Chicago, in the County of Cook, and
State of Illinois, United States of America, Manufacturer, do hereby declare the
nature of this invention for IMPROVEMENT IN DOOR CHECKS, and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
The invention relates to that type of pneumatic door-check wherein the two
companion parts, viz. cylinder and clearance piston are affixed in confronting
position upon the door and lintel respectively. When the door is wide open the
piston stands wholly tree from the cylinder but as the door swings to, the piston
enters the open mouth of the cylinder and by compressing the air before it retards
the movement of the door and causes it to close gently against the jamb.
Since one part of the pneumatic check (i.e. piston, or cylinder) as carried by the
door describes a circular arc it is necessary that some provision be made whereby
the piston and the cylinder after meeting snugly together may mutually adapt
themselves to the enforced radial path which the door fixture must pursue; and
can be so made to conform irrespective of the radial distance of the check from
the hinge-centre.
The present invention relates to an improvement in the means for effecting this
desired mutual adaptation between the clearance piston and its companion open-
ended cylinder constituting the pneumatic door-check. The exact nature of the
improvements will appear from the description following and be thereafter pointed
out by claims at the conclusion thereof.
Referring to the accompanying drawings in which like parts are designated in
like fashion throughout:
Figure 1 is a plan view of an open door and lintel having the improved pneumatic
check applied thereto.
Fig. 2 is a like view with the door closed; the cylinder being shown in section.
Fig. 3 a longitudinal sectional view of the door, lintel and piston; the cylinder
being shown in dotted lines.
Fig. 4 a detail plan view (inverted) of the wire spring to actuate the piston
packing.
Fig. 5 a transverse section view of the ball and socket sustaining joint for the
piston.
Fig. 6 a plan view of the lower socket plate.
Fig. 7 a detail view of the cylinder and piston showing modified arrangement
of the air-ports.
Fig. 8 a plan view of the internal face of the cylinder cap (Fig. 7), with a
fragment of the valve.
The cylinder A for the pneumatic check, has a bell-like mouth to readily admit
the piston head, and at its opposite end the cylinder may be completely closed or
be provided with an air vent if desired.
In the arrangement shown (Figs. 1-3) the cylinder A is conveniently attached
to the door by means of suitable brackets B; the piston in such case being secured
to the lintel or door casing. It is plain that the position of the parts of the fixture
can be reversed if desired.
The body C of the improved piston consists preferably of a coiled spring, one
end of which is furnished with a plug D having a ball-like terminal or extension d'
fitting between the socket plates E E' which are clamped snugly against the ball
by means of the screws e (Fig. 5). The lower socket-plate E is preferably
furnished with bracket arms et or other convenient device whereby the plate may

page_text: The
be attached to the door-lintel. The front edges of plate E' are usually cut away
to form a lip d² over which the stem d extends, and which can be adjusted and held
thereon in desired position as will presently appear. At its opposite end the piston
spring C conveniently carries the piston head of improved construction.
outer portion of the spring C supports a cap F perforated as at f, to allow for the
ready admission of air into the cylinder as the piston is withdrawn. The cap F is
screw threaded at its inner ledge to receive the threaded retainer ring G. A
cup-shaped washer or packing H preferably of leather or rubber, is clamped
between the flange g of the ring G and the seat 1 of the terminal cap F, the free
edge of the packing being forced outward normally by the bent metal spring I
(Fig. 4). Said spring is made by shaping a continuous wire in return bends as
shown, and then uniting the inner loops in cup-like fashion to a base ring I. The
plate I is clamped between the flange g of the retaining ring, and the inturned
portion of the washer. Ordinarily, the cap F is supplied with a vent-hole f³
controlled by a pivot flap F¹ so as to cover more or less of the opening. The
opening permits a slight escape of the air from the cylinder upon the entry of
the piston, and by adjustment of flap F the extent of vent can be varied to
modify the escape of air and thus to determine the force with which the free
swing of the door is arrested. Within the recessed part of the cap F is mounted
a valve F held normally in place to cover the opening by means of a spring F.
The spring generally bears against the lugs which project inwardly from the
ring G. The valve F closes the opening when the piston enters the cylinder,
but freely admits air to the cylinder as the piston is withdrawn.
When the cylinder A. has been mounted in place and the socket plates have
been attached in approximately opposite position, the clearance piston carried
thereby can be readily adjusted to accurately enter the mouth of the cylinder as
the door is closed. The correct position for the piston is easily determined by
loosening the socket plates E E' and swinging the door open until the piston head
clears the cylinder; by clamping the socket-plates tightly together, the piston
stem is held at proper point to insure the accurate entrance of the head within the
cylinder. As soon as the piston head enters the cylinder the spring body C of
the piston is deffected so that the piston head and cylinder are mutually adapted
to each other during the progressive swing of the door in coming to closed position.
When the parts of the door-check are separated, the spring causes the piston head
to return to normal position in readiness to confront the open mouth of the cylinder
as the door swings to. As the piston head enters the cylinder, the air is compressed
before it in cushion like fashion to prevent the slamming of the door.
gradually escapes through the opening in the piston head, the door comes to
completely closed position. Obviously, by adjusting the pivot flap f' the rapidity
of the ventage can be varied. As the piston head is withdrawn, the valve F, lifts
from its seat against the tension of spring f, and thus permits the free entry of
air through the perforations of piston head F.
As the air
al
In the modified structure (Figs. 7-8) the flexible body C of the piston or
carrier is furnished at its outer or free end with an imperforate plug having
threaded stem to receive the nut R. Between the face of the plug Q and the
nut R are clamped the washer H and its expansion spring I. The enclosing
cylinder A. has a terminal cap S threaded thereto, said cap being perforated, as at t,
to afford air-vents. The radial channels u upon the internal face of the cap S lead
from the holes t outward toward the periphery. A disc v of rubber or leather
seats internally upon the cap S and has its edge extended nearly to the interna!
rim thereof. The disc v serves as a valve for the door-check; the play of the
valve being determined by adjustment of the cap S upon the cylinder A. As the
piston head advances within the cylinder, the confined air is compressed, thus
forcing the valve v tightly against the ports t. But the radial channels » permit a
limited ventage of the air past the edge of the valve and through the openings t.
By which expedient the swinging door comes gradually to a standstill in closed
position. When the piston is withdrawn the valve is lifted from its seat upon
じ

page_text: the cap S.
the cap S and the air passes freely by port t and central hole w in disc to the
interior of the cylinder. Upon the return or inward stroke of the piston the
hole is closed by contact with the raised boss 4 extending centrally from
Manifestly the details of structure can be varied according to the skill of the
mechanic without departing from the spirit of the invention, the distinguishing
feature of which is the provision of a flexible connection or support for the
piston head, as distinguished from a stiff piston rod hinge-mounted upon a supporting
bracket, as heretofore commonly employed.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. In pneumatic door checks, the combination with an open-ended cylinder and
means for adjusting the same to the door or lintel, of a piston head, a flexible
stem for the same and means whereby said stem can be attached to the door or
lintel, substantially as described.
2. In a door-check, the combination with an open-ended cylinder or casing, of a
piston head, said parts being constructed the one for attachment to the door, and
the other for stationary attachment, and so that the two may entirely separate by
the withdrawal of the piston head from the cylinder, and a flexible body or carrier
for sustaining the piston head in manner permitting it to be entirely withdrawn
from and to re-enter the open ended cylinder, said flexible body or carrier having
one end fixed to the piston head and having its opposite end rigidly fixed to a
bracket for attachment to the door or casing, substantially as described.
3.In a door-check, the combination with an open-ended cylinder or casing, of a
piston head, said parts being constructed the one for attachment to the door and
the other for stationary attachment, and so that the two may entirely separate by
the withdrawal of the piston head from the cylinder, and a flexible connection or
support for sustaining the piston head in manner permitting it to be entirely with-
drawn from and to re-enter the open-ended cylinder, said connection consisting of a
coiled spring, substantially as described.
4. In a door-check, the combination with the open-ended cylinder or casing, of a
piston head, said parts being constructed the one for attachment to the door and
the other for stationary attachment, and so that the two may entirely separate by
the withdrawal of the piston head from the cylinder, and an elastic flexible
connection or support for sustaining the piston head in manner permitting it to be
entirely withdrawn from and to re-enter the open-ended cylinder, and means for
attaching said support to the door or lintel and for adjusting it in different
positions, substantially as described.
5.-A door-check comprising the combination with a suitable cylinder and casing,
of a piston head. a suitable flexible support for said piston head, comprising a
coiled spring, a suitable plug or attachment D for the inner end of said coiled
spring, said plug having a stem or extension, and suitable clamp plates for engaging
with the head or end of said stem or extension, and within which plates the position
of said plug can be adjusted, substantially as described.
JOSEPH KEENE.
In presence of
JAMES HARVEY ORINE.
FRED. GERLACH.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.