IMPROVEMENTS IN DOOR CHECKS OR GOVERNORS
Year: 1882

page_text: LETTERS PATENT to Alfred Julius Boult of the firm of W. P. Thompson
& Boult Agents for Foreign Patent Solicitors of 323 High Holborn in
the County of Middlesex and 6 Lord Street Liverpool in the County of
Lancaster Engineer. for an Invention of IMPROVEMENTS IN DOOR CHECKS
OR GOVERNORS." Communicated to him from abroad by The Elliott
Pneumatic Door Check Company" of Boston, Massachusetts, United States of
America
"
PROVISIONAL SPECIFICATION left by the said Alfred Julius Boult at the
Office of the Commissioners of Patents on the 27th October 1882.
ALFRED JULIUS BOULT, of the firm of W. P. Thompson & Boult, Agents for
Foreign Patent Solicitors, of 323 High Holborn in the County of Middlesex and
6 Lord Street Liverpool in the County of Lancaster, Engineer "IMPROVEMENTS
IN DOOR CHECKS OR GOVERNORS "
[A communication to him from abroad by
"The Elliott Pneumatic Door Check Company" of Boston, Massachusetts, United
States of America]
This invention relates to that class of inventions known as pneumatic door
checks.
The object of the invention is to shut or close a door and at the same time
prevent the slamming thereof and also to retain the door in an open position
when desired.
And it consists in combining in one cylinder a double cushioning force whereby
the impelling force of the spring is neutralized before the door reaches the contact
point of the sill or jamb and thereby slamming of the door is prevented.
It further consists in means for retaining the door in an open position against
the tension of the spring by arrangement of the links levers and piston rod in
combination with the cylinder
It furthermore consists in means for retaining the working cylinder and piston
rod in a true line notwithstanding the settling or sagging of the door or door
frames or buildings.

page_text: And it finally consists in the combination with the cylinder anl vent valve of a
muffling device whereby the disagreeable noise caused by the passage of air to and
from the cy in ler is obviated
The cylinder is fitted with a piston and rod round which is a coiled spring, the
rod passes through a stuffing box in one cover and its end is prolonged past the
fixed piston through a sliding piston provided with valves and passages for the air
and has a cotter, nut, or equivalent so that the sliding piston cannot pass over the
end and its travel may be regulated. The other cover of the cylinder is pierced
with holes, for the passage of air, the area of which may be regulated by a suitable
valve or equivalent and a perforated cover or muffler is provided and filled with
sponge or loose fibrous material to deaden the noise of the passing air.
Suitable levers or equivalent are provided to connect the piston rod with the
door and the whole is so arranged that the door can be fixed open and when
shutting, the force of the spring is counteracted by the cushioning of the air so that
the door shuts quietly

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alfred Julius Boult in the Great Seal Patent Office on the
27th April 1883.
Alfred Julius BOULT of the firm of W. P. Thompson & Boult, Agents for
Foreign Patent Solicitors of 323 High Holborn in the county of Middlesex, and
6 Lord Street Liverpool in the county of Lancaster, Engineer "IMPROVEMENTS
IN DOOR CHECKS OR GOVERNORS "
A communication to me from abroad by "The
Elliott Pneumatic Door Check Company," of Boston, Massachusetts, United States
of America
The object of the invention is to shut or close a door and at the same time
prevent the slamming thereof, and also to retain the door in an open position when
desired.
And it consists in combining in one cylinder a double cushioning force whereby
the impelling force of the spring is neutralized before the door reaches the contact
point of the sill or jamb and thereby the slamming of the door is prevented.
It further consists in means for retaining the door in an open position against
the tension of the spring by arrangement of the links, lovers, and piston rod, in
combination with the cylinder.
It furthermore consists in means for retaining the working cylinder and piston
rod in a true line notwithstanding the settling or sagging of the door or door
frames or buildings.
And it finally consists in the combination with the cylinder and vent valve of a
muffling device whereby the disagreeable noise caused by the passage of air to and
from the cylinder is obviated. In the accompanying Drawings :-
Figure 1 is a perspective view of an ordinary door partly open with this door
check in position.
Figure 2 is a longitudinal central section through the cylinder clearly illustrating
all the working parts.
Figure 3 shows a portion of a door to which is attached a detail of the
improvement and which forms one of the important features of the invention.
Figure 4 is a transverse sectional view of the cylinder a face view of the piston
head which shows small apertures around the piston rod for the escape of air from
one side of the piston head to the other.
Figure 5 is an end view of the cylinder showing the air controlling valves.
Figure 6 represents a plan of the door and door check, and also the various parts
showing the door open and the position of the links when closed the latter being
in dotted lines. The position now occupied by the door as shown in this figure will
be automatically retained when desired to have the door stand open, and the parts
will strike the segment shown by the dotted lines.
The same letters denote like parts in all the figures. A is the door and B the
jambs C is the cylinder, D the door fastening or pivot, E is the piston rod and F
the connecting link. G is a link pivoted to a bracket a located on the jamb of
the door and connects to a link H by a knuckle or other suitable joint b. This
link or arm H also connects to a swiveling socket L on the door. The arm [
having a pintle or pivot pin c which fits in said socket D. The socket D is
pivoted on the piece I see Figure 3 which is fastened to the door A and arranged to
adjust itself to any angle of the door either open closed or while swinging All
these parts co-operate with each other in combination with the cylinder and
mechanism therein to close the door and prevent it from slamming. Upon one

page_text: end of the cylinder is located a muffler J. This muffler is perforated on its exterior
surface, and also communicates with the interior of the cylinder by means of a
valve d. This mutter is filled with sponge or some loose fibrous material and its
object is to break the noise of the induction and eduction of the air from the
cylinder by breaking its volume into infinitisimal jets thus destroying its velocity
and consequently its noise. It is obvious that air passes into the cylinder through
the muffler as well as out.
On the other end of the cylinder C is located a stuffing box ƒ and having a
gland g through which the piston rod works. The spring in the cylinder fits over
the stuffing box it is not therefore in the way. The stuffing box is made longer
than common for the purpose of making it act as a guide for the piston rod and
thus prevent it from shunting.
I will now proceed to describe the internal parts of the cylinder and their
operations K represents the piston head which is formed of the disc follower L and
packing M. This piston head (usually rigidly fixed) loosely fits the piston rod and
has around its bore surrounding the piston rod, small apertures for permitting air
to pass through between the rod and the bore of the piston head. Upon the face
of the piston head is a disc i of leather or other flexible material which forms a
valve seat. Rigidly fixed to the piston rod is another piston head N against which
the spring works and on its opposite side is formed a valve or annular projection j
beveled to a knife edge. This valvojis designed to fit up against the flexible
disc i on the piston head K. On the end of the piston rod is an adjusting device
in this instance a pin Z which is tapering in form, but a set screw or lock nut or
other equivalent device may be used. The piston head K is adapted to have
sliding motion between the piston N and più l for the purpose of allowing the
Bexible disc i on its face to close against the valve; the object being as follows.
When the spring is drawn up the air is expelled from that portion of the cylinder
which contains the spring so that when the door is being shut to and the spring
expanding with great force, a partial vacuum is formed in the spring portion of
the cylinder and thereby retards the motion of the piston in displacing the air from
the piston end of the cylinder and thus assists the air to cushion the door against
the rapid action of the spring.
Heretofore when the spring has been drawn up the air from the outside was
drawn in by the piston, which rendered the opening of the door very difficult
because the air also had to be expelled from behind the piston through small vents.
With this device when the spring is drawn up, the air displaced passes through
the apertures between the bore of the piston head, and its rod, as well as through
the end valve K. To prevent a perfect vacuum and entirely prevent the door
from closing I adjust the small valve k to admit any desired quantity of air.
The openings or apertures of the valvo i may be readily adjusted by
lessening the space between the two piston heads by driving in the tapering pin
or if a nut be used by screwing it up. This is done according to the size of the
door and the power of resistance.
The valves & and are eccentric in their action, so that the valve openings may
be regulated and controlled as occasion may require.
The leverage of the apparatus may be varied by changing the pivoted points of
levers F and G.
The apparatus may be secured to the door and door frame by any approved
means, but brackets such as described and shown are preferred. In the pre-ent
instance the cylinder is secured to the door frame just over the door and the duplex
pivotal bracket to the door proper so that very little of the apparatus is exposed to
view. Heretofore the cylinder has been placed at right angles to the doors standing
out prominently, which looked very cumbersome and very unsightly. The
appearance of this is neat, the parts are simple in construction readily put together
and effective in operation.
Having thus described the said invention as communicated to me by my foreign

page_text: correspondents and the best means at present known to me for carrying the same
into effect What I Claim and desire to secure by Letters Patent is:-
First: The combination in a pneumatic door check of a cylinder provided with
a double piston head said heads having valves on their faces, whereby the vacuum on
one side of the heads is utilized with the air on the other side of piston heads for
forming a combined cushining and retarding medium substantially as described.
Second-The combination, in pneumatic door checks of a cylinder enclosing
operating mechanism with a muling device secured thereto to prevent the noise
either from induction or eduction of the air to or from the cylinder substantially as
shown and described.
Third: The combination in a pneumatic door check of the cylinder double piston
heads provided with valves as described and the operating spring with a muffling
device adapted to muffle the noise caused by the induction or eduction of the air
sub-tantially as described.
Fourth-The combination in a pneumatic door check of the cylinder, a piston
and spring and the air controlling valves whereby the pressure of air within the
cylinder is regulated by its admission and escape and with the noiseless muffling
device substantially as shown and set forth.
Fifth The combination in a pneumatic door check consisting of a piston rod
and tight and loose piston heads or discs one of said piston heads having a valve
and the other a valve scat the loose piston being adapted to approach to and
recede from the tight piston head and adjustable thereto, whereby when the piston
heads are moving in one direction two forces are made to retard the motion of the
piston heads, and while moving in the opposite direction the pressure in the
cylinder is equalized substantially as set forth.
Sixth The combination in a door check of the cylinder, the piston rod E link F
and links G and H the latter having a pintle or pivot-pin adapted to revolve in a
pivoted socket and said socket, also being adapted to adjust itself to any
irregularities of the settling of the door frame or sagging of the door in the manner
shown and set forth.
Seventh-In a pneumatic door check the combination with the cylinder thereof
of a duplex piston head provided with valves between them, and with a door closing
device, the valves being arranged to permit the air to pass from one side of the
pistons to the other while the piston heads are travelling substantially as described.
Eighth The combination in a pneumatic door check of the two piston heads in
one cylinder and having air valves between them said pistons being adapted for
adjustment close to each other, for the passage of more or less air between them
for the purpose set forth and shewn.
In witness whereof I the said Alfred Julius Boult have hereunto set my
hand and seal this twenty sixth day of April in the year of our Lord One
thousand eight hundred and eighty three: