An Improvement in Silent Feed and Check Mechanism.
Year: 1893

page_text: Date of Application, 30th Aug., 1893
Complete Specification Left, 31st Mar, 1894-Accepted, 5th May, 1894
PROVISIONAL SPECIFICATION.
An Improvement in Silent Feed and Check Mechanism.
:-
I, JAMES BROCKIE, of Fairview, Tyson Road, Forest Hill, in the County of
Kent, Engineer, do hereby declare the nature of this invention to be as follows:-
Mechanism of what is known as the silent feed kind employed for clutching and
feeding forward step by step a wheel or rod, or for checking the movement of a
wheel or rod urged forward by some force, so as to permit it to advance only step
by step, or gradually, as, for instance, in the regulating gear of arc electric lamps,
is apt to become worn so that the movement imparted to it for producing the
clutching action may fail. Usually the clutch consists of a rod or rim grasped
between two studs on a lever the grasping being effected when the lever is more or
less canted, or sometimes the two studs act on the sides of a groove formed in a
wheel or rod. When wear takes place on these studs, the lever carrying them
requires to be farther canted otherwise they fail to take hold. Now, according
to my invention, I mount on one of the studs a roller capable of turning partly
round the stud as an axis, and to this roller I attach an arm preferably having a
soft or elastic facing which bears against the rim, rod or surface which has to be
grasped. When the lever is canted so as to press the roller against this surface the
roller is caused by friction partly to turn and thus to press the facing of its arm
against the surface, this producing the required movement or check. Even when
the facing of the arm becomes worn, it is still pressed against the surface, as the
roller which carries the arm can turn round sufficiently to give the pressure.
When the arm has a soft facing as above, described, it operates as a smooth brake
allowing a very gradual movement of the surface on which it acts.
Dated this 30th day of August 1893.
ABEL & IMKAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improvement in Silent Feed and Check Mechanism.
J, JAMES BROCKIE, of Fairview, Tyson Road, Forest Hill, in the County of
Kent, Engineer, 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 :-
Mechanism of what is known as the silent feed kind employed for clutching and
feeding forward step by step a wheel or rod, or for checking the movement of a
wheel or rod urged forward by some force, so as to permit it to advance only step
by step, or gradually, as, for instance, in the regulating gear of arc electric lamps,
is apt to become worn so that the movement imparted to it for producing the
clutching action may fail. Usually the clutch consists of a rod or rim grasped
between two studs on a lever the grasping being effected when the lever is more or
less canted, or sometimes the two studs act on the sides of a groove formed in a
wheel or rod. When wear takes place on these studs, the lever carrying them
requires to be farther canted otherwise they fail to take hold.

page_text: Now, according to my invention, I mount on one of the studs a roller or lever
capable of turning partly round the stud as an axis, and to this roller or lever I
attach an arm preferably having a soft or elastic facing which bears against the
rim, rod or surface which has to be grasped. When the lever is canted so as to
press the roller or one arm of the lever against this surface the roller or lever is
caused by friction partly to turn and thus to press the facing of its arm against the
surface, this producing the required movement or check. Even when the facing of
the arm becomes worn; it is still pressed against the surface, as the roller or lever
which carries the arm can turn round sufficiently to give the pressure.
arm has a soft facing as above described, it operates as a smooth brake allowing a
very gradual movement of the surface on which it acts.
When the
Fig. 1 of the accompanying drawings is an elevation partly in section shewing
my invention applied to a clutch of the nature of a silent feed for controlling the
movements of the carbon holder of an arc electric lamp. Fig. 2 is a plan of the
clutch.
A is a plate through a hole in which the rod B of the carbon holder passes, and
by which, when the plate is raised to an inclined position as shewn in Fig. 1, the
rod is gripped between the edge a and the surface of a roller C. To this roller I
attach arms D between which is mounted a small roller pad or brake block E of
soft or elastic material.
When the one end of the plate A is lowered by the core F of the regulating
solenoid while the other end rests on the stop G, the rod B is released and descends,
but, in descending it tends by friction to turn C so as to press the pad E against
"the rod, thus preventing it from descending suddenly. Notwithstanding wear of E,
it will always be pressed against B when B descends and will always operate as
a brake. As shewn in Fig. 3 (in which parts corresponding to those in Figs. 1
and 2 are denoted by similar letters) the parts CD and E are carried on a frame H
pivotted by a pin 6 to the plate A. Fig. 4 shews the application of the brake E
to a wheel K which is raised along with B by the ascent of the core F to strike
the arc and is afterwards more or less released when F descends and the frame L
which carries K comes to rest on the stop G. Fig. 5 shews a modified form of the
wheel brake. As shewn in Fig. 6 and on an enlarged scale in Fig. 7, the wheel K
is made with an annular groove M, having the roller C and pad E bearing
against its one side and a shoe R (shewn separately in perspective by Fig. 7^)
bearing against its other side. Fig. 8 is a sectional plan of this arrangement, and
Fig. 9 shews a modification in which a simple arm C' is substituted for the roller C,
this arm when it is pressed against the outer side of the annular groove causing
the pad E to be also pressed against it. In all these cases, when the pad or brake E
becomes more or less worn, the action of the regulating clutch is not affected
because the arm D which carries it has simply to be turned a little farther round
in order to press E sufficiently against the rod or wheel, and by making the arm D
of radius greater than that of the roller C, or greater than the length of the
arm (Fig. 9) a very slight additional movement of C or C' round its pivot is
sufficient to give to E the farther movement required to make up for wear of the
parts.
Although I have illustrated the application of my invention to a check of the
silent feed kind employed for regulating the carbons of are electric lamps, it is
obvious that for other purposes, for which mechanism of the silent feed kind is
employed for giving or checking intermittent movements, the mechanism may be
modified in the manner described so as to allow for wear of the parts. In all such
mechanisms, the gripping or clutching effect is produced by two studs or their
equivalents being brought to bear against the opposite sides of the part which is to
be clutched. It is only necessary, in order to attain the object of my invention, to
mount on one of these pressing parts as on a pivot a roller such as C or lever such
as C¹ carrying a pad which by the movement of the roller or lever around its pivot
is made to press against the clutched part, wear being compensated by a little
additional movement given to the pad.

page_text: Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is :-
In clutch mechanism of the silent feed kiud, mounting one of the two pressing
parts on a pivot and providing it with an arm carrying a pad or its equivalent
substantially as and for the purpose set forth.
n
Mh 1004
ABEL & IMRAY,
Agents for the Applicant.