IMPROVEMENTS IN AND RELATING TO SPRING AND OTHER ROLLERS FOR WINDOW BLINDS
Year: 1878

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for the Invention
of 68
IMPROVEMENTS IN AND RELATING TO SPRING AND OTHER ROLLERS FOR
WINDOW BLINDS." A communication from abroad by John Christopher Lake,
of Camden, New Jersey, United States of America.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 8th March 1878.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. " IMPROVEMENTS IN AND RELATING TO SPRING
AND OTHER ROLLERS FOR WINDOW BLINDS." [A communication from abroad by
John Christopher Lake, of Camden, New Jersey, United States of America.]
The object of the first part of this Invention is to provide a spring blind roller
which will lock automatically when the blind is being drawn down by merely letting
go of the said blind, which will always lock before it ascends, and which will not
lock when it ascends slowly.
The said improvements consist essentially in the combination with a spring roller
of a pawl and ratchet arranged and operating as herein-after described, whereby the
said roller will be locked automatically on merely letting go of the blind on its
descent without any special manipulation, which will always lock the said roller
before the ascent of the blind, and which will not lock the said roller when the blind
is permitted to ascend slowly.
The roller shaft or spindle has an angular end, by which it is fitted fast in a
bracket, so that the roller will revolve around it under the influence of the spring.
The said shaft is preferably made in two sections, one being of wood, and having a
socket in the outer end, in which the squared inner end of the other section fits, this
said socket being protected by a metallic cap; the last-named section is of metal,
and is provided with a fast collar. A pawl is pivotted on the said collar, and an

page_text: annular rack or ratchet is fastened to the roller inside its cap; the said pawl is
double ended, having a point and tail, and is formed about midway between its
ends with an elongated slot curved to form the rounded recesses, and an inverted
arch. The pivot has a head, its shank passing through one of the slots, and the
said shank being of such diameter that the pawl can slide lengthwise upon it.
By letting go" I do not mean to imply an absolute withdrawal of the operator's
hand from the blind, though such withdrawal will be that usually employed, and
will effect the result suggested, but only such relaxation or suspension of the down-
ward pull on the blind as will permit the roller to revolve under the recoil of the
spring. As the pawl engages with the ratchet after the descent of the blind the
latter will never ascend until the roller is first locked.
The advantage of this arrangement is that the blind is not liable to fly up out of
reach, as in other cases when drawn down and suddenly let go, a practice in which
children, careless persons, and those unfamiliar with the manipulation of blinds are
apt to indulge.
With this Invention the roller is always automatically locked before the blind
ascends, and hence no such inconvenience as the sudden ascent of the blind upon
being drawn down and then released from the grasp without special manipulation
to effect the locking of the roller can ever occur.
The second part of my Invention relates to that class of blind rollers known as
friction rollers, and has reference to means whereby the friction is automatically
graduated according to the extent to which the blind is unrolled, or, what is the
same thing, according to the tension of the spring.
In spring bliud rollers when the blind is drawn down the tension of the spring is
increased, and hence when no means are provided for correspondingly increasing
the friction in friction blinds, the blind has a tendency to roll up instead of
remaining fixedly in the position to which it has been drawn down; to overcome this
defect is the object of this part of my Invention. In this case a collar is made fast
on the spindle, and a disc is loosely fitted on the said spindle, having a central
elongated slot, through which the latter passes. A lever is piyotted to a wooden
extension of the said spindle; the outer extremity of the spring is secured to a
short arm of the said lever by a lug, or by other suitable means. The longer arm
of the said lever projects through an elongated slot in the said collar, and passes
through an opening in the disc. A pin projects from the said disc through an
opening in the collar forming a pivotal connection between said parts. When the.
blind is drawn down the spring is thereby further coiled, and its tension increased ;*
its ends are drawn away from the collar, and the disc slides transversely on the
spindle, and its periphery binds against the inside of the roller to produce friction
thereon. The further down the blind is drawn the greater will be the friction
produced.
If desired a lock for preventing the recoil or unwinding of the spring when the.
roller is removed from the bracket may be used. For this purpose the aforesaid
collar is formed with a taper channel or recess, and the disc with a lug, which is
opposed to the surface of said recess. Between these parts is placed a small loose
roller. So long as the blind roller remains in its brackets the sinall roller will not
interfere with the free rotation of the blind roller, but as soon as the roller is lifted
out of the brackets the recoil of the spring will start the spindle, the small roller
dropping by gravity binds between the inner side of the said recess and the roller,"
immediately arresting the rotation of the spindle and producing a lock on the spring.
which cannot further uncoil.
This Invention has for its further object to provide a single cord roller, wherein
the spindle will operate by friction against the roller, so that when the said spindle
is locked the roller will be kept from turning to allow the blind to descend until.
sufficient drawing down force is applied to such blind to overcome the friction
between the roller and the spindle.
This part of my Invention consists essentially in forming the socket in the roller
for the recention of said spindle of less diameter than the said spindle, or a portion

page_text: of the said spindle, the said socket being coated with powdered plumbago, and the
spindle being driven thereinto.
A pulley is attached to the blind, and provided with a cord for winding it up;
the end of the roller rests in one bracket, while the spindle has its bearing in another
bracket; the said spindle has a journal which abuts against the end of the pulley
when applied to the roller. Its diameter is reduced between its ends by the
formation of an annular groove or channel, and its outer extremity is formed with
two fast radial arms; the said roller has a socket for the reception of the spindle;
the socket is coated or powdered with plumbago, and the spindle is driven thereinto,
the fibres of the wood of the said roller when the spindle is so inserted entering and
filling up the groove.
If it be desired to cause the blind to descend the latter must be drawn down
with sufficient force to overcome the friction between the spindle and the roller, the
latter being thus caused to revolve on the spindle while the said spindle remains
stationary in its bracket.
When the blind has been drawn down it will retain its position, its gravity not
being sufficient to overcome the friction between the spindle and roller, and the
said spindle and roller being kept from moving together by reason of the engage-
ment of an arm with the stop. To wind up the blind the cord is pulled down,
relieving the said arm from engagement with the stop, and causing the spindle and
roller to revolve together. When the shade is drawn up the cord is released from
the grasp of the operator's hand, or the pull thereon is released.
In a modification of this Invention, applicable to balance blind rollers, a can-
shaped disc is fitted on the spindle outside the collar, the said spindle passing
through an enlarged central opening in the said disc.
A pin projects from the inner side of the said disc through an opening in the
collar, forming a pivotal connection between the disc and collar. When the said
disc is rocked or swung in one direction on said pivot, the said disc is concentric
with the collar, but when the disc is swung or rocked in the opposite direction on
its pivot it is excentric to the collar, and a shoulder or swell projects beyond the
periphery of the said collar.
"
When the disc is concentric with the collar or not, projecting beyond the periphery
of the latter, it produces no friction on the roller, and hence the spring is free to
exert its full influence in winding up the shade.
When the blind has attained the desired altitude, the weight being dropped or
let go, the said disc falls into its excentric position, where its binds or produces
friction on the roller.
In this modification of my Invention the locking device herein-before described
may be applied, the discs forming the outer surface of the recess and the roller
fitting into said recess.
In some instances the above-described locking device may be applied to a balance
spring roller, that is to say, a roller having a spring for winding up the blind, the
latter being weighted to equalize the said spring.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Seal Patent Office on the 7th
September 1878.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN AND RELATING TO SPRING
AND OTHER ROLLERS FOR WINDOW BLINDS." A communication from abroad by
John Christopher Lake, of Camden, New Jersey, United States of America.
The object of the first part of this Invention is to provide a spring blind roller,
which will lock automatically when the blind is being drawn down, by merely
letting go of the said blind, which will always lock before it ascends, and which will
not lock when it ascends slowly.
The said improvements consist partly in the combination with a spring blind
roller of a pawl and ratchet arranged and operating as herein-after described,
whereby the said roller will be locked automatically on merely letting go of the
blind on its descent, without any special manipulation, which will always lock the
said roller before the ascent of the blind, and which will not lock the said roller
when the blind is permitted to ascend slowly.
In the accompanying Drawings,—
Figure is a longitudinal vertical section of the lock blind roller.
Figures 2, 3, 4, and 5 are transverse vertical sections of the same, showing the
various locked and unlocked positions of the pawl and ratchet.
Figure 6 is a longitudinal vertical section of the equalizing roller; Figures 7, 8,
and 9 are perspective views of details of the same; Figure 10 is a transverse ver-
tical section of the same.
Figures 11 and 11, are vertical transverse sections illustrating the application
of a locking device to said equalizing friction roller.
Figure 12 is a longitudinal vertical section of my single cord blind roller.
Figures 13, 14, and 15 represent detail views respectively of the spindle and
brackets of the same.
Figures 16 and 17 represent transverse vertical sections of a friction balance
roller; Figures 18 and 19 are perspective views of the same; Figures 20 and 21
are respectively a side elevation and longitudinal section of the collar, spindle, and
disc of the same.
Figures 22 and 23 are transverse vertical sections of the locking device applied
to a balance spring roller; and Figure 24 is a longitudinal broken section of the
same.
A designates a roller; B, its blind; C, the spring; and D, the shaft or spindle.
Said shaft has an angular end d³, by which it is fitted fast in a bracket I, so that
the roller A will revolve around it under the influence of the spring C, the opposito
ends of the latter being secured to said parts respectively. The said shaft is
preferably made in two sections d and d, the section d being of wood, baving a
socket in its outer end, in which the squared inner end of the section fits said
socket, being protected by a metallic cap d². The section d' is of metal, and is
formed or provided with a fast collar d³. E is a pawl pivoted on said collar, and
F is an annular rack or ratchet fastened to the roller A inside its cap G.
The pawl E is double ended, having a point e and tail e¹, and is formed about
midway between its ends with an elongated slot e curved to form two rounded
recesses e³ and et, and an inverted arch e. The pivot H has a head h, its shank h¹
passing through the slots es, said shank-being of such thickness or diameter that
the pawl E can slide lengthwise upon it, as herein-after set forth.
The operation is substantially as follows:-The parts described occupying their
relative positions, shown in Figure 3, the roller will be locked, the point e of the
pawl engaging with a tooth of the ratchet F, and said pawl being forced back
thereby so that the shank h of the pivot H occupies the forward recess e³ of the

page_text: slot e. To cause the blind to descend it is merely pulled down at any desired rate
of speed. On starting the blind downwardly the roller is caused to move upwardly
on its outer side, as indicated by the arrow in Figure 4, thus lifting the then
engaged tooth of the ratchet F out of engagement with the pawl E. The larger
portion of the pawl being at the moment of disengagement on the rear side or back
of the rivet H, the tail of said pawl drops by gravity and comes in contact with a
tooth of the ratchet F. The ratchet moving forwardly (as shown by the arrow in
Figure 2) the tooth on which the tail e falls passes like a wedge under said tail,
moving the pawl E forwardly until the shank h of the pivot H enters the recess e*.
This position of the pawl is shown in Figure 4, the forward part of the pawl being
then the heavier, and dropping by gravity so as to cause the point e to rest on the
ratchet F. While the blind is being drawn down the pawl occupies this position,
each succeeding tooth of the ratchet E gently lifting said pawl, but not sliding it
back on its pivot. To cause the roller to be locked the blind is merely let go.
The action of the spring immediately reverses the motion of the roller, and the
ratchet F instantly engages with the point of the pawl E, causing said pawl to be
slid back into the position shown in Figures 3 and 5, thus effecting the locking of
said roller.
To wind up the blind it is first drawn down sufficiently to release the pawl E
from the tooth fof the ratchet with which it is then engaged, the rear part of said
pawl then dropping until the tail e' meets the ratchet F. If the blind be now per-
mitted to slowly ascend, the pawl will retain the position shown in Figure 2, each
succeeding tooth of the ratchet gently lifting the tail end of said pawl, which then
falls on the tooth following. To lock the roller upon or after the ascent of the blind
the latter must be first drawn down. This causes the pawl to slide forwardly to
the position shown in Figure 4 when the locking will be accomplished by merely.
letting go of the blind. If the blind be permitted to ascend slowly the teeth f of
the ratchet F, instead of gently lifting the tail of the pawl E, as they do when the
blind ascends slowly, will by reason of the force due to their swift motion throw
said pawl up into the position shown in Figure 5, whereby the roller will be locked.
I would remark, however, that this locking of the roller when the blind ascends
rapidly is an accident of construction, or a provision for accidental cases only, as in
the ordinary usage of the blind the locking of the roller is intended to be effected
always by merely letting go of said blind in its descent, and the rapid descent of
the blind is never contemplated except as the result of accident by its slipping out
of hand. Thus it will be seen that the blind may be drawn down at any rate of
speed without locking the roller, and that the lock of the latter is effected by
merely letting go of the blind upon or after its descent without any special manipu-
lation for the purpose, the pawl on such descent of the blind being always in
position for immediate engagement with the ratchet. Also that the blind will
ascend slowly under the influence of the spring without locking the roller. Further
it will be observed that the pawl and ratchet are not caused to engage by varying
the speed of the roller through the manipulation of the blind, said roller being
locked on the descent of the blind at any speed by merely letting go of the
latter.
It will still further be observed that a lock of the roller is always effected before
the blind ascends, and that such ascent cannot be effected until a release from the
lock is first made.
#
By letting go," I do not mean to imply an absolute withdrawal of the operator's
hand from the blind, though such withdrawal will be that usually employed, and
will effect the result suggested, but only such relaxation or suspension of the down-
ward pull on the blind as will permit the roller to revolve under the recoil of the
spring far enough to make the pawl move from the position it occupies in Figure 4
to that shown in Figure 3. It will be noted that as the pawl engages with the
ratchet after the descent of the blind the latter will never ascend until the roller is
first locked.
The advantage of this arrangement is that the blind is not liable to fly up out of

page_text: .reach as in other cases when drawn down and suddenly let go, a practice in which
children, careless persons, and those unfamiliar with the manipulation of blinds are
apt to indulge.
With this Invention the roller is always automatically locked before the blind
ascends, and hence no such inconvenience as the sudden ascent of the blind upon
being drawn down and then released from the grasp without special manipulation
to effect. the locking of the roller can ever occur.
The second part of my Invention relates to that class of blind rollers known as
friction rollers, and has reference to incans whereby the friction is automatically
.graduated according to the extent to which the blind is unrolled, or what is the
same thing, according to the tension of the spring:
In spring blind rollers when the blind is drawn down the tension of the spring is
increased, and hence when no means are provided for correspondingly increasing the
.friction in friction blinds the blind has a tendency to roll up instead of remaining
fixedly in the position to which it has been drawn down. To overcome this defect
is the object of this part of my Invention.
This part of my Invention is illustrated in Figures 6 to 11 inclusive of the
annexed Drawings, wherein J is the roller; K, the blind; L, the spindle; M, the
spring; and m, m, the brackets; N is a collar fast on the spindle L; and O is a disc
loosely fitted on said spindle, having a centrally located clongated slot o, through
which the latter passes. P is a lever pivoted at p to a wooden extension of the
spindle L. The outer extremity m' of the spring M is secured to the short arm p¹
of the lever P by being hooked into a lug p² on said arm, or by any other suitable
means. The longer arm ps of said lever projects through an elongated slot n in the
collar N and passes also through an opening o' in the disc O.
A pin o pro-
jects from the disc O through an opening n¹ in the collar N, forming a pivotal
connection between said parts..
The effect and operation of this construction are substantially as follows:
When the blind is drawn down the spring M is thereby further coiled, increasing
its tension. This further coiling of the spring draws its ends m' in a direction
away from the collar N, thereby rocking the lever P on its pivot. This causes
the disc O to be slid transversely on the spindle L, and its periphery of to bind
against the inside J' of the roller J to produce friction thereon. The further
down the blind is drawn the greater will be the friction produced, and con-
versely, as the blind is raised a reverse motion of the lever will be effected,
releasing the pressure of said lever on the disc O and relieving the friction of
the latter against the wood of the roller J as the spring uncoils. If desired a
lock for preventing the recoil or unwinding of the spring when the roller is removed
from the bracket may be used in connection with the foregoing described construc-
tion. To produce such lock the collar N is formed with a tapering channel or
recess n³ and the disc O with a lug of which is opposed to the wall n³ of said recess,
said lug o³ and wall n³ thus form the two opposite sides of the recess n². Between
them is placed a small loose roller N¹. So long as the blind roller remains in its
brackets the small roller N¹ will occupy a position in the lower part and largest
part of the recess n², where it will not interfere with the fiee rotation of the blind
roller when the blind is descending or ascending. But as soon as the roller J is
lifted out of the brackets the recoil of the spring will start the spindle, revolving
said spindle, carrying with it the collar N, the recess n² becomes inverted on the
opposite side of the spindle L, that is to say, its narrowest part n is now the bottom
of the recess. The small roller N' dropping by gravity binds between the inner
side n³ of said recess, and the roller J immediately arresting the rotation of the
spindle L and producing a lock on the spring wheel cannot further uncoil.
My Invention has for its further object to provide a single cord roller wherein the
spindle will operate by friction against the roller, so that when the said spindle is
locked the rollor will, by reason of such friction, be prevented from turning to allow
the blind to descend until sufficient drawing-down force is applied to such blind to
overcome the friction between the roller and the spindlo.
"

page_text: "
This part of my Invention consists essentially in forming the socket in the
roller for the reception of said spindle of less diameter than the said spindle, or
a portion of the said spindle, the said socket being coated with powdered
plumbago and the spindle being driven thereinto, as herein-after set forth.
This part of my Invention is shown in Figures 12 to 15 inclusive of the
annexed Drawings, wherein Q is a wooden roller; Q¹, a blind; and q, a pulley
attached thereto, and provided with a cord R for winding up said blind; and
are respectively the brackets in which the roller is sustained in position when
applied to a window. The end q₁ of the roller rests in the bracket r, while the
spindle & has its bearing in the bracket . Said spindle is fully shown in Figure 13,
having a journal s which abuts against the end of the pulley 7 when applied to the
roller. Its diameter is reduced between its ends by the formation of an annular
groove o, and its outer extremity is formed with two fast radial arms 82, 8. The
roller Qhas a socket 9 for the reception of the spindle S, the diameter of said
socket being only equal to that of the spindle S at its narrowest part, or where it is
diminished by the formation of the groove 8¹. The socket 9 is coated or powdered
with plumbago, and the spindle S driven thereinto the fibres of the wood of the
said roller when the spindle is so inserted, entering and filling up the groove s¹, as
shown in Figure 13. The bracket is formed with an elongated slot for the
reception of the journal 8, and with a stop. The operation is substantially as
follows:-
The parts being relatively arranged, as shown, and the roller inserted in its
brackets, the journals naturally (by reason of the blind hanging between the
roller and the window frame, or on the inner side of the former) moves to the
inner side of the slot, whereby one of the arms 82 will come in contact with the
stop, and prevent the blind from unwinding, and the roller Q from revolving on
the spindle 8.
If it be desired to cause the blind to descend the latter must be drawn down
with sufficient force to overcome the friction between the spindle and the roller Q,
the latter being thus caused to revolve on the spindle, while said spindle remains
stationary in the bracket r¹.
When the blind has been drawn down the required distance it will retain its
position, its gravity not being sufficient to overcome the friction between the
spindle and roller, and said spindle and roller being prevented from moving together
by reason of the engagement of one of the arms 82 with the stop
To wind up the blind the cord R is pulled down, thereby drawing the journal 8
of the spindle S towards the front part of the slot 73, relieving the arm &³ from
engagement with the stop ³, and causing the spindle and roller to revolve
together.
When the blind is drawn up as far as desired the cord R is released from the
grasp of the operator's hand, or the pull thereon is released, allowing the journal
to slide backwardly in the slot, where one of the arms 82, before half a revolution
of the roller is effected, will come into engagement with the stop 73³, and prevent
the further descent of the blind.
A modification of my Invention, applicable to balance blind rollers, is shown in
Figures 16 to 21 inclusive of the annexed Drawings, wherein a cam-shaped disc U
is fitted on the spindle L outside of the collar N, the spindle L passing through an
enlarged centrally located opening u in said disc.
A pin projects from the inner side of said disc through an opening n in the
collar N, forming a pivotal connection between said disc and collar.
When the disc U is rocked or swung downwardly on said pivot, as herein-after
described, the said disc is concentric with the collar N, or at least no part of its
periphery projects beyond that of said collar.
When, on the contrary, the disc U is swung or rocked downwardly on its pivot
n it is excentric to the collar N, and a shoulder or swell u³ projects beyond the
periphery of said collar.
The operation is as follows:-The parts being arranged relatively, as shown in

page_text: Figure 17, the disc U drops until the upper side of its slot u rests on the spindle L.
Said disc is now concentric to said spindle, as already described, and the swell u³
will bind against the roller J, as shown in Figure 16, producing sufficient friction
or binding to equipose the weight attached to the blind.
By drawing down the blind with sufficient force this friction or binding may be
overcome, when the roller revolving with friction against the swell u², which remains
projected.
When, however, the weight attached to the blind is lifted for the purpose of
permitting the latter to ascend, the reverse motion of the roller under the influence
of the spring lifts the disc U, or causes it to rock on its pivot, so that the said disc
is now, as already described, concentric with the collar N, or not projecting beyond
the periphery of the latter, the lower side of its slot u resting against the under
side of the spindle L. The disc U in this position (which it retains while the blind
is ascending) produces no friction on the roller, and hence the spring is free to
exert its full influence in winding up the blind.
When the blind has attained the desired altitudes, the weight being dropped or
let go, the disc u falls by gravity into its excentric position, where it binds or
produces friction on the roller, as already suggested.
The locking device, herein-before described, may be applied to this construction
of roller, the disc U forming the outer wall of the recess, and the roller N¹ fitting
in said recess.
The lock, already described, may be applied to a common balance spring roller,
that is to say, a roller having a spring for winding up the blind, the latter being
weighted so as to equalize said spring, I have shewn means for effecting this appli-
cation in Figures 22 to 24 inclusive of the annexed Drawings, the disc O and lever
P being dispensed with.
The recess n is formed, as already described, in the collar N, the outside wall of
said recess being the cap T of the roller J, and the operation of the lock being the
same, as already described.
Having thus fully described the said Invention as cominunicated to me by my
foreign correspondent, and the manner of performing the same, I wish it under-
stood that I claim,-
First. In combination with a spring blind roller a pawl and ratchet, so arranged
that the former will engage with the latter upon simply pulling down the blind at
any speed, and release the same without any special manipulation to effect the
Jocking, and will not engage when the said blind is permitted to ascend slowly, as
above set forth.
Second. In combination with a spring blind roller a pawl and ratchet, so arranged
that said pawl will on the descent of the blind at any speed automatically assume
such position that it will engage with the ratchet and lock the roller on releasing
the blind without any manipulation of the latter, and when the blind is permitted
to ascend slowly will not engage with said ratchet.
Third. In combination with a spring curtain or blind roller a pawl and ratchet
or locking device that will lock the roller on the descent of the blind before the
latter can ascend, arranged and operating as herein described for the purpose set
forth.
Fourth. In combination with a spring blind roller having an annular ratchet a
pawl having an elongated slot, whereby the said pawl may be slid back and forth
to bring it into and out of position for engagement with the said ratchet, as shewn
and described.
Fifth. A spring blind friction roller, wherein the friction is automatically varied
to correspond with the tension of the spring or with the extent to which the blind
is unrolled, as above set forth.
Sixth. The combination with the roller, the spindle, and the spring of the
pivotted friction-producing lever P, as shown and described, and for the purpose
specified.
Seventh. The combination of the roller, the spindle, the spring, the collar, the

page_text: friction disc and the lever, constructed, arranged, and operating as shewn and
described, and for the purpose specified.
Eighth. In combination with the spindle of a spring blind roller the collar having
a taper recess n and a roller, arranged and operating to lock said roller and spring
when the former is removed from its brackets, as shewn and described.
Ninth. The combination of the roller having a socket coated or lined with
plumbago, and the spindle having a larger diameter than the said socket, being
formed with an annular groove or channel, as shown and described, and for the
purpose specified.
Tenth. The combination of the roller having its socket lined with plumbago, the
spindle having a radial arm or arms, and the bracket having an elongated slot or
bearing for the journal of the spindle and the stop, as and for the purpose set
forth.
Eleventh. In combination with a spring blind roller and spindle having a collar,
the cam or pivotted disc, arranged and operated to bind against or produce friction
on the said roller when the blind is in a state of rest, or when it is being drawn
down and relieved from binding against the said roller, or producing friction
thereon when the blind is ascending under the influence of its spring, as above set
forth.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Seventh day of September, in the year of our Lord One
hi handand and
sicht