Improvements in Boring Machines for Dentists.
Year: 1895

page_text: Date of Application, 24th June, 1895
Complete Specification Left, 13th Mar., 18:6-Accepted, 23rd May, 1396
Improvements in Boring Machines for Dentists.
I, HEINRICH RAEITHEL, of 35, Steglitzerstrasse, Berlin, in the Kingdom of
Prussia, German Empire, Locksmith, do hereby declare the nature of this invention
to be as follows:-
The object of this invention is an apparatus, by means of which the turn of the
spindle of boring machines for dentists is increased, the resistance of the lower
spiral spring is easily overcome, so that the apparatus works with greater facility.
The apparatus principally consists of an arm, fastened to the frame of the
machine, and provided with a projecting pivot, on which a lever turns, the upper
end of which is connected to the spindle of the boring machine, whilst the lower
end is furnished with a knob.
On the projecting lever, mentioned above two levers are turning, each of which
is supplied with an arm, parallel to said arm and with one bent like a horn. The
first arms are at the lower ends provided with semi-circular grooves, into which
the said knob may be inserted. The ends of the parts bent like a horn are
connected by spiral springs and are constantly pressing the semi-circular groove
against the knob. Every movement of the upper end of the lever, having the
knob, at the same time turus one of the bent arms to the opposite side of its own
direction of movement, no matter if the upper end moves to the right or to
the left.
By this arrangement an increase of the turn of the spindle of boring machines
for dentists is effected.
Improvements in Boring Machines for Dentist.
I, HEINRICH RAEITHEL, of 35 Steglitzerstrasse, Berlin, in the Kingdom of
Prussia, German Empire, Locksmith, 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 :-
The object of this invention is a device, which serves for increasing or enlarging
the amplitude of the cutter-bar of boring machines for dentists and the like, and
that for the purpose of enabling the operator to work with the machine in a very
easy and convenient manner. The device is provided with a spiral spring in such a
manner that the resistance of this spring is easily overcome, so that the apparatus
works with greater facility.
The device is illustrated in the accompanying drawing, as follows:
Fio Lie front view of the annaratus

page_text: 418 a front, and
Fig. 5 a side view of a modification, which may be applied instead of the
corresponding levers and the spiral spring of Fig. 1,
Fig. 6 is a boring machine for dentists provided with the improvements.
The arm (a) of the fork of the boring machine for dentists, which fork supports
the spindle of the driving wheel is provided with a pin (b) upon which the arm (c)
of an upper fork bearing the spindle or bar (c) is pivotted in such a manner as
to move in a side direction on the pivot (b). At the lower end of the arm (c) is
attached the knob (d), which engages with the semi-circular openings of the two
angle-levers (e) and (e¹). The angle-levers (e) and (e¹), which are also able to
move on the fixed pivot (b), are always drawn by a spiral spring (f) towards the
catch (9) riveted to the fixed arm (a), so that they are compelled to remain
always in their middle position. The angle-levers (e) and (e) and the spiral
spring (f) may also be dispensed with and replaced by the spiral spring (1), shown
in a front view in Fig. 4 and in a side view in Fig. 5. The ends of said spiral
springs (1) are also provided with corresponding openings for the knob (d) and the
catch (g). To the upper moveable arm (c), is riveted a catch (4) in such a manner,
as to move the angle-lever (e) to the left, when the arm (e) is turned to the right,
and the angle lever (e¹) to the right, in case the arm (c) is moved to the left. I
order to effect a definite turn of the arm (c), the notches in the angle-levers (e)
and (e) engaging with the catch (h), are prolonged accordingly.
The plate (i), which serves to prevent the sliding off of the separate parts
moving on the pivot (b), is fixed on the pivot (b) and the catch (9) by means of
the two screws (k). This plate however is not drawn in Fig. 1, so that the mode
of working of the angle-levers (e) and (e) may be recognised more easily.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
In boring machines for dentists the combination of the fork of the machine
provided with a pin and with a catch, with an upper fork bearing the spindle or
cutter-bar and being pivotted to the said pin and provided with a knob and with
a catch, and with two angle-levers being pivotted to the said pin and drawn
together by a spiral spring and provided with an opening engaging with the catch
at the upper end of the upper fork; as and for the purpose set forth.
Dated this 9th day of March 1896
MAX WERTHEIM.