Improvements in or relating to Dental Instruments.
Year: 1897

page_text: Date of Application, 23rd Dec
1907
Complete Specification Loft 24th Ave 1898 Accented
15th Oct. 1898
Complete
pecification Loft 24th Aug 1898 Accented 15th Oct.. 1898
PROVISIONAL SPECIFICATION.
Improvements in or relating to Dental Instruments.
A communication from ALDEN BUSH, of 111, Lake Avenue, in the City of
Elyria, County of Lorain, State of Ohio, United States of America,
Inspector-Mechanic.
I, ALFRED JULIUS BOULT, of 111, Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention to be as
follows:
The invention relates to an improved dental plugger or similar instrument
adapted to be connected to and operated by, the flexible shaft of the dental engine
to the end that a quick succession of blows shall be delivered against the filling
in the dental cavity by the plugging tool connected with the instrument. The
object of the invention is to provide a simple and effective device of this character,
which may be easily manipulated by the operator to properly regulate the force
of the blows, and which will not be clumsy to handle, and which may be quickly
connected with the engine shaft.
A tubular casing which together with the tubular sheath (which surrounds it),
and a tubular sleeve or extension, constitutes the hand piece of the instrument.
This sheath rests at its lower end on a shoulder on the casing and is locked in
this casing is joined by a screw thread with the tubular bearing sleeve.
Within the bearing sleeve is a longitudinally movable tool-holding plunger.
This plunger is limited in its outward movement by its flange which impinges against
the shoulder at the upper end of the sleeve; and is prevented from rotating by
means of a pin projecting from it into a slot in the sleeve. The tool extends
into a tubular hole in the plunger and is clamped therein by means of a nut
the interior of which is tapered at its lower end and which screws over a cor-
respondingly tapered and screw threaded end of the plunger, this end being
split to allow the nut to contract it tightly around the tool.
Rotatably journalled in the plug is a shaft which is adapted to be secured to
the driving flexible shaft or corresponding member of a dental engine. On this
shaft and within the casing is an annular flange which, together with the shaft
and the lower end of the plug furnishes a ball race between which roll balls.
The balls, however, may be omitted, in which case the flange will bear against
the inner end of the plug.
A hammer, serves to transfer motion from the shaft to the plunger
and transform that motion. It may be a rigid part of the shaft, but prefer-
ably it is a separate piece which is journalled at its upper end in a cylin-
drical recess in the lower end of the shaft, and at its lower end by having a
plug which it carries extending into a cylindrical recess in the upper end of
the plunger. Loosely surrounding the upper end of the hammer is a sleeve which
has on its upper end ratchet teeth which are adapted to engage with similar.
ratchet teeth on the lower end of the shaft. This sleeve is pressed toward that

page_text: shaft by a spring between itself and a flange on the hammer, and is prevented
from rotating by a pin on the hammer projecting into a notch in the sleeve. The
operation of this construction is that when the shaft is rotated in one direction
the hammer is driven thereby, but when the shaft is rotated in the opposite
direction, and there is appreciable resistance to the rotation of the hammer, the
ratchet teeth simply drive the sleeve downward and slip over the top of that
sleeve without rotating the hammer.
On the lower end of the hammer are formed ratchet or cam teeth (which face
in the opposite direction to the teeth on the lower end of the shaft); and on the
upper end of the plunger are corresponding ratchet or cam teeth. A. spring,
bearing at its upper end against the flange on the hammer, and at its lower end
against the flange at the upper end of the plunger, tends to separate the hammer
and the plunger. This is the condition which the parts have when not in use;
and it will be understood that a rotation given to the hammer has no effect on
the plunger. If, however, the plunger is pressed relatively upwards, the set of
teeth come in contact and as the hammer rotates these teeth sliding upon each
other force the casing away from the plunger until the teeth slip off of each
other, when the plunger and hammer come together with a jar and a blow is
delivered by the lower end of the pin striking the bottom of the cavity in the
upper end of the plunger.
The necessary connections having been made between the dental engine shaft
and the shaft of the plugger, the operation is as follows: The operator places the
end of the tool against the filling to be compacted and presses thereon with greater
or less force but with sufficient force to cause relative motion of the casing and
the plunger against the force of the spring, whereby the teeth on the plunger
and hammer respectively are caused to contact with each other. The revolution
of the hammer and the engagement of the cam surfaces of the teeth cause the
hammer, and with it the casing to be moved away from the filling, this movement
taking place in opposition to the pressure from the operator's hand. When the
straight edges of the ratchet teeth coming into apposition allow such action,
the pressure from the hand of the operator moves the casing and with it the
hammer toward the filling, thereby causing the pin to strike the plunger more
or less violently. The force of this blow is determined by the pressure from the
operator's hand. This pressure may be as great as desired, the balls receiving
the thrust caused thereby without undue friction. If, when the hammer and
plunger are in engagement the dental engine shaft should be revolved in the reverse
direction no harm would be done for the sleeve would be simply forced downward
and the shaft would thus rotate without affecting the hammer or plunger.
It is to be noticed that the blow is not due to the action of a spring. It is
due to the force exerted by the operator. The hammer is moved backward
against such force by the cam or ratchet teeth and when this action of the teeth
suddenly ceases the pressure of the operator's hand forces the hammer against
the plunger. This action is very rapid and by means of the described mechanism
the operator delivers blow after blow upon the end of the plunger for an
indefinite period and with great rapidity. The rapidity with which these blows
are delivered may be increased by making the number of ratchet teeth on the
hammer one less or one greater than the number of the corresponding teeth on
the plunger.
Particular attention should be called to the fact that until the plunger is
moved inward by the described pressure from the hand of the operator the revolu-
tion of the hammer produces absolutely no effect upon the plunger, the spring
holding the plunger and hammer so far apart that the cam teeth on these parts
do not engage with each other.
1
30
1
P T
1007

page_text: Improvements in or relating to Dental Instruments.
A communication from ALDEN BUSH, of 111, Lake Avenue, in the City of
Elyria, County of Lorain, State of Ohio, United States of America,
Inspector-Mechanic.
I, ALFRED JULIUS BOULT, of 111, Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
The invention relates to an improved dental plugger adapted to be connected
to and operated by the flexible shaft of the dental engine to the end that a quick
succession of blows shall be delivered against the filling in the dental cavity by
the plugging tool connected with the instrument. The object of the invention
is to provide a simple and effective device of this character, which may be easily
manipulated by the operator to properly regulate the force of the blows, and
which will not be clumsy to handle, and which may be quickly connected with
the engine shaft.
In the drawing, Figure 1 is an elevation of the improved plugging instrument,
and Figure 2 is a longitudinal central section of the same.
Referring to the parts by letters, A represents a tubular casing which together
with the tubular sheath B (which surrounds it), and the tubular sleeve C. con-
stitutes the hand piece of the instrument. This sheath Brests at its lower end
en a shoulder on the casing and is locked in place by a plug E screwing into
the upper end of the casing. The lower end of this casing is joined by a screw
thread with the tubular bearing sleeve C.
Within the bearing sleeve C is a longitudinally movable tool-holding plunger D).
This plunger is limited in its outward movement by its flange d which impinges
against the shoulder at the upper end of the sleeve; and is prevented from rotat-
ing by means of a pin projecting from it into the slot el in the sleeve. The
tool, which is designated F, extends into a tubular hole in the plunger D and
is clamped therein by means of a nut G, the interior of which is tapered at its
lower end, and which screws over a correspondingly tapered and screw threaded
end of the plunger, this end being split to allow the nut to contract it tightly
around the tool.
Rotatably journalled in the plug E is a shaft J which is adapted to be secured
to the driving flexible shaft or corresponding member of a dental engine. On
this shaft and within the casing A is an annular flange j, which, together with
the shaft and the lower end of the plug E, furnishes a ball race between which
roll balls K. The balls, however, may be omitted, in which case the flange j
will bear against the inner end of the plug E.
The hammer, which serves to transfer motion from the shaft J to the plunger D
and transform that motion, is represented by L. It may be a rigid part of the
shaft, but preferably it is a separate piece which is journalled at its upper end
in a cylindrical recess in the lower end of the shaft J, and at its lower end by
having a pin which it carries extending into a cylindrical recess in the upper
end of the plunger. Loosely surrounding the upper end of the hammer is the
sleeve M which has on its upper end ratchet teeth m which are adapted to engage
with similar ratchet teeth on the lower end of the shaft J. This sleeve is
pressed toward that shaft by a spring H between itself and a flange on the
hammer, and is prevented from rotating independently of the hammer by a
pin 13 on the hammer projecting into a notch m³ in the sleeve. The operation

page_text: of this sleeve and the ratchet teeth and m is that when the shaft J is rotated
in one direction the hammer L is rotated, but when the shaft is rotated in the
opposite direction, and there is appreciable resistance to the rotation of the
hammer L the ratchet teeth simply push the sleeve M downward and slip over
the top of the teeth m without rotating the hammer.
On the lower end of the hammer L are formed ratchet or cam teeth 12 (which
face in the opposite direction to the teeth on the lower end of the shaft J); and
on the upper end of the plunger D are corresponding ratchet or cam teeth d³
A spring P, bearing at its upper end against the flange and at its lower end
against the flange d at the upper end of the plunger, tends to separate the
hammer and the plunger. This is the condition which the parts have when not
in use; and it will be seen that a rotation given to the hammer L has no effect
on the plunger. If, however, the plunger is pressed relatively upward, the
teeth contact with the teeth and as the hammer rotates these teeth sliding
upon each other force the casing away from the plunger until the teeth slip off
of each other, when the plunger and hammer come together with a jar, and a
blow is delivered by the lower end of the pin 7 striking the bottom of the cavity d³.
The necessary connections having been made between the dental engine shaft
and the shaft J of the plugger, the operation is as follows: The operator places
the end of the tool F against the filling to be compacted and presses thereon
with greater or less force, but with sufficient force to cause the relative motion
of the casing A and the plunger D against the force of the spring P, whereby the
teeth on the plunger and hammer respectively are caused to engage with each
other. The revolution of the hammer and the engagement of the cam surfaces
of the teeth 12 and d³ cause the hammer, and with it the casing, to be moved
away from the filling, this movement taking place in opposition to the pressure
from the operator's hand. When the straight edges of the ratchet teeth, coming
into apposition, allow such action, the pressure from the hand of the operator
moves the casing A and with it the hammer toward the filling, thereby causing
the pinto strike more or less violently the plunger D. The force of this blow
is determined by the pressure from the operator's hand. This pressure may be
as great as desired, the balls K receiving the thrust caused thereby without undue
friction. If, when the hammer and plunger are in engagement, the dental engine
shaft should be revolved in the reverse direction, no harm would be done for
the sleeve M. would be simply forced downward and the shaft would thus rotate
without affecting the hammer or plunger.
It is to be noticed that the blow is not due to the action of a spring. It is
due to the force exerted by the operator. The hammer is moved backward
against such force by the cam or ratchet teeth and, when this action of the
ratchet teeth suddenly ceases, the pressure of the operator's hand forces the
hammer against the plunger. This action is very rapid, and, by means of
the described mechanism, the operator delivers blow after blow upon the end of the
plunger for an indefinite period and with great rapidity. The rapidity with
which these blows are delivered may be increased by making the number of
ratchet teeth 12 one less or one greater than the number of corresponding
teeth d3.
It should be particularly observed that, until the plunger is moved inward by
the described pressure from the hand of the operator, the revolution of the hammer
produces absolutely no effect upon the plunger, the spring P holding the plunger
and hammer so far apart that the cam teeth on these parts do not engage with
each other.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, as communicated
to me by my foreign correspondent, I declare that what I claim is: -
1. A dental plugger having the construction and operation substantially as f

page_text: 2. In a dental plugger, the combination of a tubular casing having, near its
lower end, an internal offset forming an annular shoulder, and a plunger work-
ing through said end and having on its inner end an external annular shoulder
and a row of cam teeth, with a plug secured in and closing the upper end of
said casing, a rotatable hammer in said casing having an annular row of cam
teeth on its lower end and an external annular flange above its lower end, a
spring surrounding the hammer and thrusting endwise against the plunger and
the flange on the hammer, and a shaft which rotates said hammer and passes
through the plug in the upper end of the casing, the part of the shaft which
passes through the plug being of smaller diameter than the part of the shaft which
is below said plug and in the casing, substantially as specified.
3. In a dental plugger, the combination of a casing, having near the lower end
an offset which forms an internal annular shoulder, a plug secured in and closing
the upper end of said casing and forming an annular internal bearing, a longi-
tudinally movable tool-holding plunger which works through the lower end of
the casing and has an annular flange in the casing above said shoulder and also
an annular row of cam teeth on its inner end, with a rotatable hammer in the
casing having cam teeth on its lower end and an external annular flange, a
spring surrounding the hammer and thrusting endwise against said flange and
the inner end of the plunger, and a shaft adapted to rotate said hammer, which
shaft projects through the plug in the upper end of the casing and has within
the casing an annular enlargement and a row of anti-friction balls placed be-
tween said annular enlargement and the inner end of the plug, substantially as
specified.
4. In a dental plugger, the combination of a casing, a tool holding plunger
which projects through the lower end of the casing and has an annular row of
cam teeth on its inner end, a rotatable hammer mounted in the casing having on
its end which is adjacent to the plunger an annular row of cam teeth, the
adjacent ends of said hammer and plunger having respectively a striking pin
and a recess in which said pin operates, a spring exerting its force to separate
the two annular rows of cam teeth, and a shaft extending out of the upper end
of the casing for rotating the hammer, substantially as specified.
5. In a dental plugger, the combination of a casing, a plunger movable
through one end of the casing having on its inner end an annular row of cam
teeth a rotatable hammer in said casing having on its lower end an annular row of
cam teeth and also having an external flange above its lower end, and a coil spring
surrounding the hammer and thrusting endwise against said flange and the inner
end of the plunger, with a plug closing the upper end of the casing, a rotatable
shaft which passes through said plug and has an annular row of cam teeth on
its inner end, a collar surrounding the upper end of the hammer and having on
its upper end an annular row of cam teeth, a pin for preventing the relative
revolution of the hammer and sleeve, and a spring which thrusts said sleeve
upward to cause the engagement of the cam teeth on its upper end with the cam
teeth on the inner end of the shaft, substantially as specified.
6. The complete dental plugger substantially as described and illustrated in
the accompanying drawings.
Doted this 24th day of incest 1808