Year: 1888

page_text: We JOHN GEORGE WITTE and WILLIAM LEWIS WITTE of No. 75 Chambers Street
in the City of New York in the County and State of New York, United States of
America, Merchants, 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 :-
These improvements relate principally to a door spring so arranged with relation
to a door and jamb, by means of a system of links and levers, that but a comparatively
small range of movement suffices to charge it with the force required to enable it to
close the door, however widely the door may be open, and in so doing to overcome
the resistance of a door check to the concluding portion of the closing movement of
the door. It is herein shown as combined with a door check of the type described in
Letters Patent of Great Britain, No. 16796, dated December 6th 1887.
The characteristic feature of said door check is that the latter portion of the closing
movement of the door is controlled by the frictional action of a brake upon the
periphery of a pivotted buffer in the form of an excentric or scroll cam, which, by
means of a spring or its equivalent, is made to present its longer radius for initial
engagement with the brake, and by thereafter rocking upon its pivot, affords for the
brake a bearing of gradually diminishing radius.
The door spring, and the appurtenances of the system of links and, lovers with
which it is immediately connected, may be mounted upon the jamb band, be connected
by means of a link with the door, or may be mounted upon the door, and connected
by a link with the jamb; the latter form is that which has been selected for illustration
in the accompanying drawing, which are as follows:-
Fig. 1, is a partial front elevation of a door and jamb to which the improvement
is applied, showing the parts in the positions which they occupy when the door
open at an angle of about 35°.
Fig. 2 is a top view showing the door open at an angle of 35°.
Fig. 3 is a top view showing the door open at 140°.
TA
1

page_text: Fig. 5 is a top view showing the door nearly closed, but with the brake block and
buffer removed to afford a better view of the other parts of the structure.
Fig. 6 is a front elevation of the face plate D.
The drawings show a door, A, which is hung to a jamb or door frame, B, by the
usual hinges (). Affixed to the upper part of the door is a face plate, D, to which is
pivotally connected an arm E, swinging upon a vertical axis. The vertical cross-bar e,
which connects the upper horizontal member e¹, with the lower horizontal member e²,
of the arm E, is transversely perforated to admit the screw bolt f, which, at its inner
extremity, is connected with one end of the strong contracting spiral spring F, the
opposite end of which is connected to the link F', pivotted to a lug d, affixed to, or
formed in one piece with the face plate D. Laterally projecting lugs D1 and D², also
affixed to, or formed in one piece with the face plate D, afford the seats, respectively,
for the upper and lower ends of the vertical pivot E¹, which constitutes the axis of
the arm E.
the
The pivotted connection of the link F¹, to the lug d, is a little to one side of the
pivot E, and hence the contracting force of the spiral spring F tends to pull the free
end of the arm E sidewise towards the side of the face plate D, with which the inner
end of the spring F is connected. The outer end of the arm E has pivotally connected
to it one extremity of the shouldered link G, the other extremity of which is pivotally
connected to the outer end of the link or chain H, the inner end of which is pivotally
connected with a suitably perforated lug i, affixed to, or formed in one piece with the
small face plate I, secured to the jamb of the door. When the door is opened,
pull of the link or chain H upon the outer end of the arm E, compels the arm to
rock upon its axis toward the hinges of the door, and to thus distend the spiral
spring F. In case it be desired to increase the extent of such distension, there is
provided an adjustable screw stop J, which is inserted transversely through the face
plate D into the door, and the head of which projects into the path of movement of
the link F¹, so that at a prescribed stage in the outward movement of the door, the
side of the link F1, by being brought into collision with the screw stop J, is prevented
from further rocking upon its axis. The effect of such collision is to hold back the
end of the spring F, which is connected to the link F1, and to thereby compel a
further distension of the spring F, when the door is further opened, as illustrated in
Fig. 3. By this device, the apparatus is adapted for employment in connection with
doors differing in weight. When the door is very heavy, the adjustable screw stop J
is turned outward, so that the link F¹ acquires collision with it soon after the door
commences to open. If a less heavy door is used, the adjustable screw stop J is
not turned out so far, and the collision of the link Fi with the head of the screw stop
being thereby delayed until a later stage of the opening movement of the door, there
is a less extent of distension of the spring F.
It will be seen that the pull of the spring F upon the outer end of the arm Ę is
transmitted, by means of the links G and H, to the jamb to which the inner end of
the link H is connected, and that in the act of opening the door, the arm E is
necessarily compelled to swing toward the hinges of the door, because the link H
is fastened to a part of the jamb which is nearer the axis of the door than is the pivot
upon which the arm E swings. Thus the force required to open the door must be
sufficient to overcome the force with which the spring F resists distension. Similarly,
when the door is released after being opened, the contracting force of the spring
tending to rock the outer end of the arm E away from the hinges of the door, exerts
upon the door, in a direction tending to close it, an amount of force equal to that
expended in opening the door. The adjusting screw bolt extends through the
crossbare of the arm E, and is provided upon its outwardly projecting portion with
the adjusting nut f. It will be seen that by appropriately turning the adjusting
nut, the tension of the spring F may be increased or diminished to the extent
which may be desired for the particular door to which the apparatus is applied. If
the apparatus should be used for a door incapable of being opened more than 90°,
the link G might be rigidly affixed to the outer end of the arm E, but when the
door is to be opened more than 90°, for illustration, as shown in Fig. 3, to, 130° or

page_text: more, the link G comes into play as a means of affording the required radial
elongation of the connection between the face plate affixed to the jamb, and the
outer end of the arm E.
In the course of the closing movement of the door, the shoulder g of the link G
is carried into collision with the side of the arm E, or, preferably, with the end of
the adjustable stop g¹ inserted transversely through the arm E, in which position it
remains until the door is again opened widely. The adjustable stop g₁ serves to
regulate the position which the arm E assumes when the door is closed. Turning
the stop gl in or out against the shoulder g, changes the angle of the link G with
the link H, and thus changes the distance between the outer end of the arm E
and the face-plate I affixed to the jamb. There is thus afforded a means of adjusting
the apparatus with reference to its application, without any cutting away of the
jamb, in cases where there is a greater or less projection of the jamb moulding
beyond the vertical plane of the closed door. The adjustable stop g¹ also affords a
means for effecting a delicate adjustment of the amount of tension which the spring F
exerts when the door is in its closed position. In practice, the parts will usually be
so proportioned that when the door is closed, the arm E will be brought to rest in a
position substantially a right angle with the face of the door, while the shoulder g will
be in contact with the arm E. When so proportioned, the apparatus is well adapted
for application to a door and jamb the faces of which are in the same vertical
plane.
the arm E
It will be seen that by screwing in the stop g¹ against the shoulder 9,
will be rocked toward the hinged edge of the door, and to the extent to which it is
so rocked, the spring F will be distended, and the force which it exerts upon the
closed door will be thereby increased. This means of delicately adjusting the spring F
is of a special use when the apparatus is to be employed upon a door provided with
the well-known electrical unlatching device; in which case it is desired that when
unlatched, the door shall spring outwardly a short distance from the jamb. To
accomplish this purpose, there is provided the arm-stop K, which may be simply a
screw inserted in a hole tapped in the face-plate D, as shown, and projecting
outwardly therefrom a sufficient distance to afford a bearing at its outer end k for
the shoulder E formed upon the side of the arm E, as shown. By suitably adjusting
the position of the arın stop K, the door may be relieved from the force of the
spring Fat any desired stage in the latter part of its closing movement, for example,
at such a stage that the momentum of the door, after it has been relieved from the
force of the spring F, will just suffice to latch it, and in so doing to overcome the
force of the spring employed in electrical unlatching devices, the purpose of which
is to open the door slightly when it is unlatched.
Inasmuch as the door-closing spring arranged as described is, by a very small
range of opening movement of the door, charged with the required force, it is
especially adapted for employment in combination with door checks of the type of
that hereinbefore referred to, in which a strong force is required to overcome the
friction of the brake upon the buffer during the door checking operation. Here-
tofore the required force has been supplied by means of a supplemental spring,
which was not brought into action until the door had partially completed its closing
movement, the initiatory closing movement of the door being effected by the main
door spring. In the present case, it will be seen that the force stored up in
the spring F by the act of opening the door, is sufficient not only to impart the
initiatory closing movement, but to enable the door to overcome the frictional
resistance due to the bearing of the brake L upon the periphery m of the scroll-
shaped buffer M during the latter portion of the door closing operation.
It has been customary heretofore to employ an adjustable spring for rocking the
buffer upon its axis as soon as it was released from the brake, in order to have it
present its longer radius for initial engagement with the brake during the closing
movement of the door, and also for the purpose of slightly adding to the force
required to rock the buffer upon its axis. The present invention, however, embraces
an especial device for conveniently and accurately adjusting the tension of the buffer

page_text: spring with reference to the state of adjustment of the door-closing appurtenances,
by means of which the action upon the door of the spring F is regulated.
This device consists of a spring adjusting arm m', which has one end fastened to
the face of the buffer M, by the screw.m³, and has its other extremity connected with
the spiral buffer spring M. By loosening the screw m², the arm m¹ may be rocked
in either direction to increase or diminish the tension of the buffer spring M', and
having been moved to the desired position, is secured therein by tightening the
screw. m².
It will of course be understood that the door-closing spring F and the arm E, and
the links G and H, constituting the peculiar lever system by means of which the
spring F is enabled to supply the force required to close the door, without itself
requiring to be greatly distended, may be employed in connection with other forms
of well-known door-checks, or without any door check, in cases where door checks
are not desired.
There is however a peculiar mode of action of the buffer check when employed as
shown in the drawings, which consists in an increased range of sliding movement of
the surface of the buffer upon the surface of the brake, due to the fact that the buffer
is pivotted upon the swinging arm E, so that the axis of the buffer, instead of moving
merely in an arc of the circle of which the hinge of the door is the axis, has an
additional movement resulting from the swinging of the arm E upon its axis E¹. As
is obvious, this increases the range of sliding movement of the periphery of the buffer
upon the surface of the brake, and the same result ensues whether the arm and buffer
are mounted upon the jamb, and the brake upon the door, or, as shown in the
drawings, the brake is affixed to the jamb, and the arm and buffer mounted upon
the door.
It is to be remarked that the brake L is simply a strip of steel fastened, as shown,
to the diagonal face n of the brake supporting block N, which block will be made of
greater or less thickness accordingly as the face of the jamb projects in a less or
greater degree outward from the vertical plane of the surface of the door when
closed.
The instrumentality which connects the small face plate I with the shouldered
link G, has been hereinbefore referred to as the "link or chain .H." It will of course
be seen that a flexible chain might be substituted for the rigid link shown in the
drawing, as a means of connecting the link G with the face plate I. In practice, the
links Hand G will be so proportioned that their combined length, when straightened
out, will be sufficient to enable them to extend from the perforated lug i to the outer
end of the arm E in the position which it acquires when the door is opened 180°.
The apparatus, as a whole, is so organised that it is readily made applicable to
doors opening either to the right or to the left. To this end, the two holes K¹
and Kare tapped in the face plate, and the arm E, in addition to being provided
with the shoulder E2 upon one side, is provided with a similar shoulder E³ upon the
opposite side. In the drawing, the arm stop K is shown as inserted through the
hole K', and it is thus adapted to bear upon the shoulder E². By removing the arm-
stop K from the hole K, and inserting it in the hole K, it is brought into position
to bear upon the shoulder E³, and to thus serve as a stop for the swinging arm E,
when the apparatus is applied to a door opening in the opposite direction from that
shown in the drawing. In such case, other changes of arrangement of the parts are
made, as follows:-The lug d, instead of being inserted in the hole d¹ tapped in the
face plate, is inserted in the hole ; after the screw-stop, J, has been removed
therefrom.
By this change, the spring F is made to exert its. pull upon the arm E in the
opposite direction to that in which it exerts it when arranged as shown in the
drawing.
The screw-stop J, when inserted through the hole d', is adapted to effect the dis-
tension of the spring F by acting upon the side of the link F1 opposite to that which
is acted upon when the parts are arranged as shown in the drawing. The free end
of the arm E; instead of being connected with the jamb on the right side of the brake

page_text: block N, as shown, requires in this case connection with the jamb on the left of the
brake-block. To that end, the pivot G¹ is removed, the shouldered link G is detached
from the arm E, and the links G and H and the face plate I being then turned
upside down, the shouldered link G is again connected with the free end of the arm E
by the reinsertion of the pivot G. The adjustable screw stop 9' is unscrewed from
the arm E, and inserted the opposite way through the hole tapped therein in order
that it may now serve to bear upon the shoulder g in the reversed position of the
link G with relation to the arm E. The face-plate I is appropriately fastened to the
jamb to the left of the brake-block N, which is turned upside down before being
fastened to the jamb.
The only remaining change required is to reverse the position of the scroll-shaped
buffer, which is effected by removing it from its bearing, together with its spring M³,
and then turning it upside down, and replacing it in its bearing with the spring Mi
beneath the buffer M, instead of above it, as shown in the drawing. It will thus be
seen that without the discarding of any of the parts of the apparatus, or the substi-
tution therefor of any other parts, and by a mere change in the positions of the parts,
the apparatus is equally.adaptable for application to doors opening either to the right
or left.
As has been explained, the apparatus shown is reversible, that is, the parts shown
as mounted upon the door, may be mounted upon the jamb, in which case the parts
mounted upon the jamb may be mounted upon the door. It will therefore be under-
stood that the terms door and jamb, occurring in the claims, are to be regarded as
transposable.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. An arm pivotally mounted at one end upon the door, and swinging upon an axis
parallel with the axis of the door, a spring carried by the door, and arranged to exert
its force upon the arm in the direction required to rock the arm away from the hinged
edge of the door, a suitable linked connection for connecting the arm with a point on
the jamb nearer the axial line of the door than the radial distance between the axis
of the arm and the axis of the door, in combination with an armstop affixed to the
door, and projecting into the path of movement of a part of the swinging arm, for
arresting the swinging movement of said arm at a prescribed stage in the closing
movement of the door.
2. A swinging arm pivotally mounted at one end upon the door, a spring for
rocking the said arm away from the hinged edge of the door, a linked connection for
connecting the jamb with the free end of the arm, and thereby controlling the rocking
movement of the arm during the closing movement of the door, in combination with
a door check for opposing a prescribed amount of resistance to the closing movement
of the door.
3. A swinging arm pivotally mounted at one end upon the door, a spring for
rocking the said arm away from the hinged edge of the door, a linked connection.
for connecting the jamb with the free end of the arm, and thereby controlling the
rocking movement of the arm during the closing movement of the door, in combi-
nation with a scroll-shaped buffer pivotally mounted upon the said swinging arm,
and a brake affixed to, and projecting laterally from the jamb, for engaging the
periphery of said buffer during the latter portion of the closing movement of
the door.
4. The swinging arm E, the buffer M pivotally mounted thereon, and the buffer
spring M¹, in combination with the spring adjusting arm m' and the fastening
screw m².
5. The swinging arm E, the contracting spring F connecting the free end of the
arm E with a point on the door nearer the free edge thereof than the axis of the
arm E, in combination with the shouldered link &, the adjustable stop g', and

page_text: the link H, 'connecting the free end of the arm E with the jamb, as and for the
purposes set forth.
6. The swinging arm E mounted upon the door, and linked to the jamb, the
contracting spiral spring F, the link for connecting to the door the end of
the spring F opposite that connected with the arm E, in combination with the adjustable
screw stop J, for increasing the distension of the spring F by its collision with the
link F at a prescribed stage in the swinging movement of the arm E, resulting from
the opening of the door.
7. The combination, as herein set forth, of the swinging arm E, mounted upon
the door, and linked to the jamb, a spring acting upon the rocking arm in such
direction as to tighten its connection with the jamb, and an adjusting screw connected
with said spring for the purpose of varying the normal tension thereof.
8. The swinging arm E carried upon the door and linked to the jamb, the spring F
suitably connected at one extremity with the free end of the arm E, and at the other
extremity with the lug d, in combination with the stop J, face plate D, having the
holes d', and j, tapped in it, as and for the purpose set forth..
Dated this 23rd October 1888.
NEWTON & SON,
Agents for the Applicant.