Improvements in and relating to Door Checks.
Year: 1895

page_text: Date of Application, 16th July, 1895-Accepted, 17th Aug., 1895
COMPLETE SPECIFICATION.
Improvements in and relating to Door Checks.
I, EUGENE IRVING BLOUNT, of Gardner, in the County of Worcester and
State of Massachusetts, United States of America, Gentleman, do hereby declare
the nature of this invention, and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement :-
This invention has relation to contrivances employing liquid for automatically
closing doors without slamming, the liquid co-operating with a spring and a piston.
It is the chief object of the invention to insure the presence of an efficient body of
liquid at the rear of the piston when the door is opened, so that the force of the
door-closing spring will be exerted against a body of liquid. The invention also
has for its object to provide means whereby the pressure of the piston against the
liquid may be decreased or avoided during the opening of the door, thus obviating
liability of the liquid to be forced into the spring chamber through the packing
surrounding the spindle.
To these ends, the invention consists in the improvements which I will now
proceed to describe and claim.
Reference is to be had to the annexed drawings and 'to the letters and figures
marked thereon, forming a part of this Specification, the same letters designating
the same parts or features, as the case may be, wherever they occur.
Of the drawings—
Figure 1 is an end elevation of a door check and closer embodying my
invention.
Figure 2 is a top plan view, part being represented as broken away.
Figure 3 is a longitudinal sectional view taken on the line 3-3 of Figure 1, the
piston being shown as just arriving at the extremity of its rearward movement...
Figure 4 is a view similar to Figure 3, showing the piston at the other extremity
of its movement.
Figure 5 is a horizontal sectional view taken on the line 5-5 of Figure 1.
Figure 6 is a cross-sectional view taken on the line 6-6 of Figure 5.
Figure 7 is a sectional detail view taken on the line 7--7 of Figure 2, showing
the form of the valve-seat.
In the drawings-
a designates the enclosing casing which comprises the spring chamber 6, the
liquid space a¹ under said chamber, and the cylinder c extending outwardly from
said liquid space. d is the arm, connected with the spindle e and the spring by
usual or suitable means, and in like manner connected to the door. f is the piston,
which is arranged to be reciprocated in the cylinder between the end g and the
point or line h, the stroke of the piston being of such length relatively to the
length of the cylinder that the piston at all times constitutes a closely fitting
partition across the cylinder, preventing movement of the liquid into the outer end
of the cylinder excepting through the by-passes hereinafter described. The piston
may be reciprocated by means of a crank-and-pitman connection with the spindle e,
as herein shown, or in any other suitable or known way.
i designates a comparatively large or free passage-way or by-pass connecting the
liquid space a at the side of the piston with the other end of the cylinder c at the
opposite side of the piston, the said by-pass being provided with a suitable valve,
herein shown as a ball-valve j so constructed and arranged that when the piston f
is moved toward the liquid space a' by the opening of the door to which the device
:

page_text: may be attached the said valve will be automatically opened; and when the piston
is moved in the opposite direction by the door-closing spring, the said valve will be
closed. The by-pass i communicates with the liquid space a' at a point below the
top of the latter, so that in the event of leakage or evaporation of the liquid from
said space, causing an air space above the liquid, there will be no corresponding
air space in the cylinder, so long as the liquid in the space a¹ remains above the
end of the by-pass. I denominate the by-pass i the "flow by-pass," to distinguish
it from the return by-pass hereinafter described.
k designates a second and restricted passage-way or by-pass also connecting the
liquid space with the outer end of the cylinder. The said by-pass k is controlled
as to the extent to which fluid may pass therethrough, by a valve of suitable
character, herein shown as a screw-valve, and need not necessarily be automatic in
its operation: The function of the by-pass k being to return the liquid at a
relatively slow rate from the cylinder to the liquid space, I denominate it the
"return by-pass:"
Both of the by-passes are shown as formed in the sides of the casing outside of
the piston, but the form and arrangement of the said by-passes is not of the
essence of my present improvement, being necessary only that they should
connect the outer end of the cylinder at one end of the piston with the liquid
space a¹ at the opposite side of the piston, and that they be located a sufficient
distance below the top of the cylinder to keep their outer ends in constant com-
munication with the liquid in the chamber and prevent such loss of liquid as will
be likely to occur from uncovering the said by-passes, the object. being to prevent
air from being sucked through said by-passes to the outer end of the cylinder when
the door is being opened. *
'
With this construction and arrangement of parts it will be seen that when the
door is opened and the piston is drawn toward the liquid space a¹, as represented in
Figures 3 and 5, the liquid in advance of the piston will be freely drawn or sucked
through the by-pass i to the outer end of the cylinder, the valve j moving back
from its seat m (see Figures 2, 3, and 5). A limited quantity of the liquid may
also flow through the restricted by-pass k, as shown by the arrows in Figure 3.
By these means, the door may be opened without material resistance.
When the door is released, the action of the spring will tend to close the same,
and the tendency of the liquid to flow back through the by-passes to the liquid
space a¹ will force the valve ; to its seat m (see Figures 4 and 8), and the only
course for the liquid will be by way of the restricted by-pass k, checking the
force of the spring in the usual way and allowing the door to be closed without
slamming.
It will be seen that by this construction I avoid a valve or valves and corre-
sponding ports in the piston, the piston being solid or valveless, so that it prevents
any movement of liquid through it, the only transfer of liquid from one side of
the piston being through the by-passes. Hence, when the piston is moving
outwardly, during the operation of opening the door, liquid is drawn or sucked
by the piston through the by-pass i into the outer end of the cylinder, and said
outer end is therefore kept full of liquid.
The chief advantage of the described improvement is that the height of the
liquid forced into the outer end of the cylinder by the piston during the opening
movement of the door is not limited by the height of the liquid in the liquid
space a', so long as the accumulation of liquid in said space is sufficient to cover
the ends of the by-passes. In other words, the suction or vacuum caused in the
outer end of the cylinder will cause the latter to be filled with liquid, without
regard to the height of the liquid in the space a', so long as the by-passes are
below the liquid in the said space. The level of the liquid in the space a¹ is
liable to be reduced by evaporation or leakage after long continued use. If the
liquid were transferred to the outer end of the cylinder through a valved orifice in
the piston, its level in the outer end of the cylinder would necessarily be the same
as that in the liquid space a¹; hence there would necessarily be a quantity of air

page_text: in the outer end of the cylinder when the door is opened, corresponding to the
height of the liquid in the space a¹. It will be seen, however, that there can be a
considerable loss of liquid from the casing without permitting the entrance of air
into the outer end of the cylinder when the door is being opened. This is an
important advantage, since it greatly prolongs the period of usefulness of a charge.
of liquid, and renders it unnecessary to re-charge excepting at long intervals."
Another advantage is the absence of any considerable force or pressure on the
liquid in the space a¹ by the piston when the door is being opened. When the
displaced liquid is compelled to pass through a valved port in the piston while
the latter is moving forward, there is more or less pressure exerted by the piston
on the liquid in the liquid space a', tending to cause leakage of the liquid through
the packing of the spindle e into the spring chamber, particularly when there is a
full charge of liquid. This tendency I avoid, because the liquid displaced by the
piston is drawn away from the packing of the spindle e to the outer end of the
cylinder, there being no pressure of the liquid toward said packing, the piston
acting to exhaust the liquid from the liquid space.
The spindle e passes through a packing-nut p, which is formed in a single piece
and comprises the lower portion 2 closely fitting the spindle, the annular chamber 3
located above said lower portion and communicating with the interior of the nut,
said chamber receiving the liquid that may find its way. upwardly between the
spindle and the portion 2 of the nut, the back-flow ports 4 for the return of the
liquid to the main liquid space, the inwardly projecting flange 5 above the liquid
chamber 3, and the packing chamber 6 above the said flange. The nut also has an
external screw-thread 8, whereby it is screwed into the partition separating the
spring chamber from the liquid chamber of the casing.
The chamber 6 is formed to hold packing material p¹, preferably in the form of
rings of leather, around the piston. An annular adjusting follower p³ is screwed
into the upper end of the nut, the latter being internally screw-threaded to engage
the nut p³. A metal washer pt bears on the packing, and between said washer, and
the follower is interposed a helical spring p³, which exerts a downward pressure
on the packing through the washer p* and keeps the packing compressed around the
spindle. The follower p³ may be adjusted from time to time, to increase the
pressure of the spring on the packing, as may be required, said follower being
provided with slots in its upper side to engage a suitably formed wrench or spanner.
The follower p³ is removable from the nut, so that the packing can be readily
removed and renewed.
I do not confine myself to the described improvement in connection with a com-
bined door check and closer, or in other words, to an apparatus which includes as a
part of its structure a door-closing spring, as said improvement may be used in a
door-check which is not provided with a spring chamber and spring, and is used to
retard the closing movement of a door when said movement is caused by an
independent spring applied at some other point.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, 1 declare that what I
claim is :
1. An apparatus of the character specified, comprising a casing having a liquid
space, a cylinder extending outwardly from said space, and a by-pass connecting
the liquid space with the outer portion of the cylinder and provided with a valve
which permits free movement of the liquid from said space to the outer end of the
cylinder and prevents a return movement of said liquid, a solid or valveless piston
closely fitting said cylinder, and a spindle operatively connected with the piston to
reciprocate the latter, said cylinder being longer than the stroke of the piston, so
that the piston at all times constitutes a partition preventing movement of liquid to
the outer end of the cylinder excepting through the by-pass, whereby the liquid is
exhausted or sucked from the liquid space into the outer portion of the cylinder
when the piston is moving toward said space.

page_text: 2. An apparatus of the character specified, comprising a casing having a liquid
space, a cylinder extending outwardly from said space, a flow by-pass, and a return
by-pass, said by-passes connecting the liquid space with the outer portion of the
cylinder, the flow by-pass having a valve which permits free movement of liquid
from said space to the outer end of the cylinder and prevents a return movement of
said liquid, while the return by-pass permits a restricted flow of liquid from the
outer end of the cylinder to the liquid space, a solid or valveless piston closely
fitting said cylinder, and a spindle operatively connected with the piston to
reciprocate the latter, said piston constituting a closely fitting partition, whereby
transfer of liquid is prevented excepting through said by-passes.
3. An apparatus of the character specified, comprising a casing having a spring
chamber, a liquid space below said chamber separated from the spring chamber by
a partition, a spindle extending from the spring chamber into the liquid space, the
spindle packing nut screwed into said partition and provided at its lower portion
with an annular liquid chamber communicating with the interior of the nut,, back-
flow ports extending downwardly from the bottom of said chamber, an inwardly
projecting flange above said chamber, and the packing chamber above said flange,
the annular packing supported by said flange, the screw-threaded annular adjusting
follower engaged with the internally threaded upper portion of the nut, and the
spring interposed between said follower and the packing.
4. A door check and closer comprising a casing having a spring chamber, a liquid
space below said chamber, a cylinder extending outwardly from said space, and a
by-pass connecting the liquid space at a point below its top with the outer end of
the cylinder, said by-pass being provided with a valve which permits free movement
of the liquid from said space to the outer end of the cylinder and prevents a return
movement of said liquid, a solid or valveless piston closely fitting said cylinder, and
a spring-controlled spindle extending through a suitable packing from the spring
chamber into the liquid space and operatively connected with the piston to
reciprocate the latter, the said cylinder being longer than the stroke of the piston,
so that the valveless piston at all times constitutes a closely fitting partition
preventing movement of the liquid to the outer end of the cylinder excepting
through the by-pass, whereby the liquid is exhausted or sucked from the liquid
space when the piston is moving toward said space and is therefore not only
deprived of any pressure tending to force it through the packing into the spring
chamber but is also caused to fill the cylinder above the height of the liquid in the
liquid space when the charge of liquid 'has been reduced by leakage.
Dated this 28th day of June 1895.
EUGENE IRVING BLOUNT..
Haseltine, Lake & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.