Improvements in Electrical and other Recording Instruments.
Year: 1896

page_text: Date of Application, 21st Oct., 1897
Dt.... 1000
1000
PROVISIONAL SPECIFICATION.
Improvements in Electrical and other Recording Instruments.
I, JOHN HENRY BARKER, Electrical Engineer, of The Cambridge Electric
Supply Company Limited, Thompsons Lane, Cambridge, do hereby declare the
nature of this invention to be as follows:-
My invention relates principally to improvements in electrical measuring in-
struments in which the readings are automatically recorded on a paper strip, but
it may also be applied to other recording instruments, such as barometers, ther-
mometers and the like. In such instruments the paper strip is usually moved
by clockwork, and only a comparatively small part of the scale provided on the
paper strip is used in ordinary working. In instruments where the strip is sup-
ported on one drum only, the strips usually require to be changed once a day,
so that 365 of them would be used in a year. They are thus troublesome to file
and refer to.
My invention consists in a method of and means for enabling the instrument
to make the record on any chosen part of the width of the strip, preferably auto-
matically, beginning near one edge of the strip, making a record there during
one longitudinal movement of the strip, then automatically causing the recording
point and strip to be moved relatively to one another so that the second record
is produced on a part of the strip adjacent to the first record. At the end of
the next complete longitudinal movement of the strip a similar relative movement
is again caused, and the record is thus shifted a corresponding distance across the
strip. In this way the whole width of the paper strip may be used, and if six
such movements be made, the strip which previously required to be changed
once a day will now last for seven days, or for seven of the original periods.
In carrying my invention into effect according to one modification, taking for
example an instrument where the force to be measured produces a torque on an
axle in the instrument; a pointer on the same axle serving to make the record
on a strip carried on a drum driven by clock-work. I divide the
pointer of the instrument into two parts, one rigidly connected to the
axle of the instrument, and carrying a quadrant supporting a series of pins,
each one longer than the preceding one; the other pivotted on the same axis as
the first, and so held by gravity or by a spring that it will remain in contact
with one or other of the pins on the quadrant, and so be moved by the rigid part
producing a record on the drum strip. On the completion of one revolution of
the drum I cause the free part of the pointer to be moved so as to clear the first
pin, and be drawn against the second pin on the quadrant, thus changing the
position of the recording point on the drum. This movement of the free part of
the pointer may be done automatically from the drum or the clock-work of the
drum. On the completion of each further revolution of the drum the free part.
/

page_text: of the pointer is moved to the next pin, each time moving the position of the
recording point on the paper. The drum and paper strip may be made wide
enough to allow of seven records being thus produced on the same strip.
Dated. this 21st day of October 1897.
MARKS & CLERK,
Agents for the Applicant,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.
Improvements in Electrical and other Recording Instruments.
I, JOHN HENRY BARKER, of The Cambridge Electric Supply Company
Limited, Thompson's Lane, Cambridge, Electrical 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:
My invention relates principally to improvements in electrical measuring in-
struments in which the readings are automatically recorded on a paper strip, but
it may also be applied to other recording instruments, such as barometers, ther-
mometers and the like. In such instruments the paper strip is usually moved
by clockwork, and only a comparatively small part of the scale provided on the
paper strip is used in ordinary working. In instruments where the strip is sup
ported on one drum only, the strips usually require to be changed once a day,
so that 365 of them would be used in a year. They are thus troublesome to file
and refer to.
My invention consists in a method of and means for enabling the instrument
to make the record on any chosen part of the width of the strip, preferably 'auto-
matically, beginning near one edge of the, strip, making a record there during
one longitudinal movement of the strip, then automatically causing the recording
point and strip to be moved relatively to one another so that the second record
is produced on a part of the strip adjacent to the first record. At the end of
the next complete longitudinal movement of the strip a similar relative movement
is again caused, and the record is thus shifted a corresponding distance across the
strip. In this way the whole width of the paper strip may be used, and if six
such movements be made, the strip which previously required to be changed
once a day will now last for seven days, or for seven of the original periods.
In carrying my invention into effect according to one modification, taking for
example an instrument where the force to be measured produces a torque on an
axle in the instrument, a point on the same axle serving to make the record
on a strip carried on a drum driven by clockwork.
I divide the pointer of the instrument into two parts: one rigidly connected to
the axle of the instrument, and carrying a quadrant supporting a series of pins,
each one longer than the preceding one; the other pivoted on the same axis as
the first; and so held by gravity or by a spring that it will remain in contact
with one or other of the pins on the quadrant, and so be moved by the rigid part
producing a record on the drum strip. On the completion of one revolution of
the drum I cause the free part of the pointer to be moved so as to clear the first
pin, and be drawn against the second pin on the quadrant, thus changing the
position of the recording point on the drum. This movement of the free part of

page_text: the pointer may be done automatically from the drum or the clock work of the
drum. On the completion of each further revolution of the drum the free part
of the pointer is moved to the next pin, each time moving the position of the
recording point on the paper.. The drum and paper strip may be made wide
enough to allow of seven records being thus produced on the same strip.
Referring to the accompanying sheet of drawings,
Figure 1 is an elevation of a Holden hot wire voltmeter, with my improved
recording apparatus applied to it.
Figure 2 is a side elevation and,
Figures 3 and 4 show details of Figures 1 and 2.
In applying my invention to a Holden hot wire recording voltmeter:
A is the base of the instrument; B is the drum on which the recording strip
is fixed; C is the part of the pointer which is fixed to the axle pivot D of the
instrument, E is the movable part of the pointer carrying the pen E.
1..
The arm C has at its end a plate or quadrant C which has ratchet teeth pro
vided on its edge adapted to engage with the part E of the pointer which is
pivoted loosely on the axle D. The part 2 of the pointer E beyond the pivot
is loaded so that the pointer E bears on any of the teeth of the arm C with a
practically constant force.
The pointer C is operated by the hot wire F by means of the bearing roller G
and arm H in the usual manner, between the two stops I and I¹.
On the drum B I provide an inclined bar B¹ which may also be the bar used
to fasten the paper on the drum. The incline of the bar B1 is such that as it
passes under the pen it raises the latter and thereby the pen carrier E clear of the
tooth on the quadrant C against which it is resting. The pointer or pen
carrier E immediately swings against the next tooth on C¹ thus taking up the
next position for recording, on the paper strip.
I find it advantageous to provide that each record shall be complete without
using that part of the drum where the inclined bar B¹ is placed, and that the
arm shall be moved through that small space such as from P to P¹ by a gravity
or spring device as shown at the end of the drum in Figures 1 and 2.
I provide a ratchet disc J into which gears a pawl K. To the disc J I attach
a cord L which passes over the pulleys MM to a weight N. An inclined pro-
jection O is provided on the drum which at each rotation of the drum raises the
ratchet pawl. When the disc J is held by the ratchet pawl K the drum B turns
under the action of the clock but when the projection lifts the ratchet pawl K
the disc J is pulled rapidly round by the weight N and takes with it the drum B
till the pawl K falls into the next notch in the disc J: then the disc is stopped,
and the drum goes on rotating slowly under the action of the clock.
The pen will thus have been shifted by the inclined bar B' as before described.
Ribs such as B2 may be provided on the inclined bar BI to aid in preventing
the pen-carrying pointer from shifting more than one tooth laterally at a time.
The disc J in one form of the apparatus is fixed to the clock spindle and the
drum rotates on this spindle being driven by the clock mechanism. This spinille
is carried on the bearings Q. Q', and would rotate with the clock and drum under
the pull put on the disc J by the weight N, but is retained by the ratchet pawl K
until the projection O lifts the latter thus allowing rotation. The pawl K drops
into the next tooth and prevents further rotation of the drum and disc by the
weight till on a complete revolution of the drum the projection 0 again lifts the
pawl.
The disc J may be driven by an attached coil spring instead of by gravity.
I arrange the clock drum so that each period of time is complete in the are of
the drum that is used for recording and clear of the arc that is used for shifting
the pen from one recording strip to the next.
In a similar manner I may apply this invention to any known type of recording
instrument.

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
1. In recording instruments the shifting of the recording point at the end of
each period to make a record on a fresh portion of the recording strip, substan-
tially as described.
2. Dividing the pointer in a recording instrument into two parts and provid-
ing on one a set of projections with each of which the other part is adapted to
engage, while the instrument is recording: the recording point being shifted by
the drum from each to the next following projection at the end of each record,
substantially as described.
3. In recording instruments as claimed in Claim 1 causing the drum to be
shifted through an arc by means of a spring or weight independent of the clock
mechanism substantially as described.
4. The improved recording mechanism substantially as herein described and
illustrated.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.