Rheostats.
Year: 1897

page_text: Date of Application, 20th July, 1897 -Accepted, 23rd Oct., 1897
Rheostats.
We, OSCAR HENRY PIEPER, of 34 Atkinson Street, and ALPHONSE FERDINAND
PIEPER, of 15 Grant Park, both in Rochester, in the County of Monroe and State
of New York,. U.S.A., gentlemen, 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:
Our present invention has for its object to provide an improved rheostat
particularly adapted for use in connection with a cataphoric apparatus used in
dental operations to convey a local anesthetic to the gum or nerve centers liable
to be affected by the operation. In using an apparatus of this nature it is
desirable not only that means be provided for the accurate regulation of the
electric current, but that the operator be advised of the amount of current applied
in order that the best results may be obtained. With the object in view of
providing a rheostat which will fulfil the conditions required in a cataphoric
appliance, and one that can, if desired, be used for other purposes, our invention
consists in certain improvements hereinafter described, the novel features being
pointed out particularly in the claims at the end of this Specification.
In the drawings:
Figure 1 is a front elevation of our improved rheostat.
Figure 2, a bottom plan view of the same with the bottom plate removed.
Figure 3, a sectional view on the line - of Fig. 2.
Figure 4, a perspective view showing the manner of constructing the resistance
coils and contacts.
Figure 5, a sectional view of a portion of the resistance coils and supports.
Figure 6, a similar view of a modification.
Figure 7, a diagrammatic view, of the circuits.
Similar reference numerals in the several figures indicate similar parts.
In carrying out our invention we provide a suitable case, preferably circular,
and embodying the back plate 1 and the front plate or cover 2 of insulating
material, as hard rubber, and casing 3 connecting the two parts. Secured to the
rear side of the front plate 2 is a frame or spider 4 having arms 5 to which the
resistance coils and contact plates are secured by means of brackets 6 projecting
over the edge of the coils and supports and adjustably secured to the arms 5 by
screws 7, suitable insulating material 8 being applied between the brackets and
frame, as shown articularly in Figure 3. Extending through the center of
the casing and journaled in a central bearing formed in the spider 4 is a sleeve 10
having a worm wheel 11 formed upon or secured thereto, and a friction disk 12
at its inner end; said 'worm wheel co-operating with a worm 13 on a shaft 14
mounted in suitable bearings in the spider and extending out through the casing,
its outer end being provided with an operating handle or knob 15. Inside of
the sleeve 10 is a tubular arbor or sleeve 16 having secured to its outer portion
an operating knob or handle 17 and inside of this an index or pointer 18 co-
operating with a scale 20 on a suitable dial, preferably under a glass 21. The
[Pine Rd 1

page_text: inner end of the arbor 16 is connected by a screw 22 with an arm 23 carrying
at its outer or free end a contact spring 24 adapted to wipe over the contact plates
of the coils supported upon the arms 5 of the spider. 29 indicates a stop for
arresting the arm 23 when it has reached the end of the resistance coil and
the pointer is at zero. Extending through the arbor 16 is a rod 25, having a
threaded outer end, upon which is a nut 26 and provided at its inner end with
a head 27 adapted to co-operate with a friction plate 28 mounted upon the sleeve 16
and permitted a movement thereon longitudinally of said sleeve, but caused to
rotate with it by means of the screw 22, which passes through the slot therein,
as shown in Figure 3. The construction of the parts just described is such that
when the nut 26 is loosened, the sleeve 16 may be manipulated by the knob 17
carrying with it the index 18, the friction disk 28 and the arm 23, which latter
may be readily moved to cause the contact spring to pass over the contact plates,
and, as will be explained, place more or less resistance in the circuit. When,
however, the nut 26 is tightened, the disks 28 and 12 will be drawn into contact,
and as the latter carries the worm wheel 11, the arm 23 can only be operated
by a manipulation of the operating knob 15 on the worm shaft, so that the
resistance in the circuit can only be gradually varied, which is very desirable
when the device is used for cataphoric purposes. It will be seen that the operator
may by connecting the disks 12 and 28 vary the resistance in the circuit gradually,
the exact amount of current passing being indicated upon the dial 20, and, if
desired, may return the index and switch arm gradually to first position, or
he may unscrew the nut 26 and by the manipulation of the knob 17 return the
instrument to normal position rapidly.
It is evident that as far as the operation of the parts just described is concerned,
the particular construction of the resistance coils and contacts is immaterial, but
it is eminently desirable that it be of such construction that it is readily applicable
to the general form of instrument described and capable of being made at a
reasonable price. These results we find are best accomplished by building up,
on a suitable ring, coils of relatively fine insulated wire between which coils
are placed the contacts with which the moveable arm of the rheostat co-operates,
and the construction employed is shown particularly in Figures 4, 5 and 6, the
base or core being composed of a rod 30, preferably of metal, such, for instance,
as copper, upon opposite sides of which are placed strips 31 of insulating material,
as vulcanized fibre, slightly greater in width than the rod 30, and upon the core
thus formed are placed alternately metal plates 32 and insulating and separating
washers 39, preferably of vulcanized fibre, until a strip of a length equal to the
circumference of the circle described by the contact spring 24 has been formed,
and then the end plates 33 are secured to the ends of the strip 31 by means of
pins 34, as shown in Figure 5, or otherwise. The resistance coils 35 are com-
posed of fine insulated wire wound upon the washers 33 between the plates 32
and are all formed from a continuous piece, the requisite number of turns to
form the desired resistance or unit being arranged between the two adjacent plates 32,
then the wire is passed over the rear side of said plate and into the space between
the next two plates, this being continued until all the spaces between the contact
plates are filled with the desired number of turns. To connect the separate
Coils with the contact plates it is only necessary to remove the insulation from
that portion of the wire passing over the outer sides of the plates 32 with a file
or sand-paper and solder the bare wire to the plates, as shown particularly in
Figure. 5. The coil strip is then bent into circular form and the plates 33 con-
nected by screws 36, the circle is then trued up, and, if desired, the inner faces
of the plates: are ground to make a smooth contact surface over which the spring
contact arm 24 moves. If desired, the spaces between the contact plates 32' and
the outside of the coil may be filled with insulating material 37, or the ring
as a whole may be imbedded in insulating material with only the edges of the
plates projecting, thereby forming a continuous surface, or in some instances it

page_text: may be desirable to place insulating plates 40 of mica, or other material, on
opposite sides.of the plates 32, as shown in Figure 6, which would prevent the
formation of a spark between the plates if currents of high voltage were employed.
One of the line terminals from the generator is connected to binding post 50,
which is connected by wire 51 with binding post 52, from which latter a wire,
or other suitable conductor, leads to the cataphoric instrument, or other trans-
lating device. From the binding post 50 a conductor 53 leads to one end of the
resistance coil, and the other end of the coil is connected by a wire 54 with a
switch contact 55 with which co-operates a movable switch 56 connected by a
wire 57 with the post 58 to which the other terminal of the generator circuit
is connected. The binding post 59 forming the other terminal of the circuit
containing the translating device is connected by a wire 60 with the spider or
frame 4, and the latter is connected through the arm 23 and contact spring 24
with one or the other of the contact plates of the rheostat.
From the circuit arrangement shown in Figure 7 it will be seen that, as the
arm 23 is moved around either by the operating knob 15 or the knob 17 in the
direction of the arrow Figure 2, the resistance is gradually diminished and
there is a gradual increase in the current passing to the patient or the trans-
lating device, the index and scale indicating the current passing in volts rather
than the number of ohms interposed as resistance.
It will be understood that this apparatus can be used for any purpose for which
a rheostat is desired, and the manner of constructing the resistance coils can be
employed in connection with other forms of apparatus, whether the contacts of
said coils be arranged in circular form or otherwise, but the construction is par
ticularly adapted to such an arrangement as herein shown, because the coils
and their support can be readily formed while said support is straight, if desired,
and then it may be bent into circular or other form and the space between the
contact plates filled with insulating material, as may be desired.
Having now particularly described and ascertained the nature of our said in-
vention, and in what manner the same is to be performed, we declare that what we
claim is:-
1. In a rheostat, the combination with a support or core and a series of con-
ducting contact plates insulated from the support and having apertures through
which the support passes, of a continuous insulated wire wound upon the support
between the plates of the series and electrically connected to the plates at the
points of crossing from one space to the next, and a contact arm co-operating
with the exposed edges of the plates, substantially as described.
2. In a rheosiat, the combination with a support or core, a series or conducting
contact plates insulated from the support and having apertures through which
the support passes, and a series of insulated spacing washers on the support and
between the contact plates, of a continuous insulated wire wound upon the
washers between the plates, and electrically connected to the plates at the points
of crossing plates, and a contact arm co-operating with the exposed edges of
the plates, substantially as described.
:
:
3. In a rheostat, the combination with the divided ring support or core, a
series of contact plates having apertures through which the ring passes, of a
continuous insulated wire wound upon the support between the plates, and
electrically connected to the plates at the points of crossing and a rotary contact
arm adapted to contact successively with the exposed edges of the contact plates,
substantially as described.
4. In a rheostat, the combination with the flexible support or core, a series
of contact plates having apertures through which the support passes, and a series
of washers of insulating material on the support, between the plates, of a con-
tinuous insulated wire wound upon the support between the contact plates and
electrically connected to the latter at the points of crossing from one space to

page_text: the next, said wire being connected to one circuit terminal and the movable
contact arm connected to the other circuit terminal and adapted to be moved
over and contact with the edges of the plates, substantially as described.
5. In a rheostat, the combination with the rod 30, the insulating strips 31,
the contact plates 32 and insulating washers 39, of the continuous insulated
wire 35 wound upon the washers and electrically connected with the plates 32
as it passes over them, the plates 33 at the ends of the support, and means for
connecting them, and a movable contact arm-adapted to co-operate with the edges
of the plates 32, substantially as described.
6. In a rheostat, the combination with a variable resistance and a movable
contact arm co-operating therewith, of an operating knob or handle connected
directly with said contact arm for actuating it, a second operating knob or
handle and a slow gear mechanism connected thereto, and a detachable clutch
device between the slow gear mechanism and the contact arm, whereby the contact
arm may be actuated directly at high speed or indirectly at a lower speed, sub-
stantially as described.
7. In a rheostat, the combination with a variable resistance, and a movable
contact arm co-operating therewith, of an operating knob or handle connected
directly with said arm, a worm wheel, a detachable clutch device between said
worm wheel and the contact arm, and a worm co-operating with the worm wheel
and an operating knob or handle connected thereto, substantially as described.
8. In a rheostat, the combination with a variable resistance, and the movable
contact arm, of the arbor to which the contact arm is connected, and the
operating knob and index thereon, the scale with which the index co-operates,
the worm wheel loose on the arbor, the worm shaft co-operating therewith having
the operating knob or handle, and a clutch between the arbor and worm wheel
substantially as described.
9. In a rheostat, the combination with the variable resistance and the movable
contact arm, of the arbor 16 to which the arm is connected having the knob 17,
the worm wheel 11 and the friction disk 12, the worm shaft 14 having the
worm 13 and knob 15, the friction disk 28 moving with the contact arm, and the
rod 25 having the head 27 and nut 26 for clamping the worm wheel and arm
together, substantially as described.
10. In a rheostat, the combination with the frame having the arms 5, the
variable resistance embodying the coils and contact plates mounted on the said
arms, the arbor 16, the index thereon, the contact arm 23 on the arbor, the worm
wheel connected to the arbor, the worm and the worm shaft having the operating
knob, substantially as described.
1007
BOULT & WADE,
Agents for the Applicant.