IMPROVEMENTS IN TOOL HOLDERS FOR DENTAL ENGINES to be as follows:
Year: 1884

page_text: 1 AUGUST WEBER of the City and State of New York, United States of
America do hereby declare the nature of said invention for "IMPROVEMENTS IN
TOOL HOLDERS FOR DENTAL ENGINES to be as follows:-
"
Dental engines have been made with a hand piece containing a drill or other
tool, and a flexible shaft that is rotated by foot or other power, and in some
instances the tool has been in an angle attachment so as to occupy a position at
right angles or at an inclination to the body of the hand piece.
My invention relates to the angle attachment and it consists in means for
securing the tool in a firm and reliable manner so that it cannot become loose
when in use, and the parts are very compact and strong so as to occupy but
little space.
The holder or stock contains the rotary shaft aforesaid and at the end of such
shaft is a mitre gear driving a similar gear that surrounds a tubular shaft. This
tubular shaft passes transversely through the tubular stock or holder.
Within the
tubular shaft is a tubular chuck, split towards one end and having a conical
exterior surface. The drill, burr, or other tool is received into the chuck and
clamped by the action of a nut upon the back end of the tubular chuck that draws
the conical portion along into the tubular shaft and so compresses the split portion
of the chuck around the drill or tool to hold it.
The end of the tubular shaft, outside the bevel gear is conical, so as to set into a
corresponding recess, in one side of the stock, this forms a conical bearing to
prevent the tubular shaft moving end wise. At the other side of the stock there is
a similar conical recess for a conical washer around the tubular shaft, and the screw
nut around the tubular chuck presses upon this washer and there is a pin in the
tubular chuck passing into slots in the tubular shaft and into a notch in the washer
50 that all three parts revolve together but the tubular chuck can be moved
endwise to clamp or unclamp the tool by the action of the nut. Looseness or end
motion to the shaft is prevented by the conical bearings aforesaid. The tool is
slotted at its inner end and notched so as to catch upon the inner end of the
.

page_text: aforesaid pin and more firmly hold the tool and cause it to revolve with the chuck
and shaft.
The stock or holder is usually provided with a tubular split sleeve that can be
slipped over the end of the ordinary hand piece used in dental engines so that the
shaft in such sleeve will pass into the tool holder of such hand piece and be
revolved by the flexible shaft. There is a tubular bearing for the shaft, that also
serves to connect the split sleeve and the stock and there is a movable cap that
covers the nut, to prevent the latter coming in contact with any part of the mouth
while it is revolving with the tool.

page_text: I AUGUST WEBER, of the City and State of New York, United States of
America, do hereby declare the nature of my said invention for IMPROVEMENTS
IN TOOL HOLDERS FOR DENTAL ENGINES, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:-
Angle attachments have heretofore been' made for dental engines in which the
tool is held in a revolving stock, but in consequence of the small space in the
mouth where such angle attachment usually is employed it is difficult to make the
parts sufficiently small.
Besides this, if there is any looseness of the drill or tool in the stock, the tool
does not work accurately and is liable to be broken or to come out of the stock.
My invention is for securing the tool into the stock in a very firm manner, so that
it can not become loose in use, and there is no risk of the tool coming out of the
chuck nor of the stock binding or becoming too loose in the holder and the parts
are very compact and strong and occupy but little space.
In the drawing
Fig. 1. is a side view of the attachment in about the ordinary size.
Fig. 2. is a longitudinal section of the attachment.
Fig. 3. is a cross section of the same at the line x, x.
Fig. 4. is an elevation and
Fig. 5. is an end view of the chuck.
Fig. 6. is an elevation of the notched end of the tool.
Fig. 7. is an end view of the same.
Fig. 8. is a section at the line y. fig. 2.
All the figs. except fig. 1. are shown in enlarged size.
I make use of a holder in which is a rotary shaft a. with a bevel gear wheel b.
at the end which meshes into the gear wheel c. and d. is the drill or tooth which is
revolved for drilling or excavating dental cavities.
These parts are of a character corresponding generally to the devices shown in
British Letters Patent No 1017 of 1864.
The shaft a. passes through the tubular bearing f. and at g. is a sleeve screwed
at 2. to the bearing f. This sleeve g is split so as to be elastic and it is slipped
over the end of the ordinary dental hand-piece and the shaft a. is grasped by the
chuck or tool holder of the hand-piece so as to be revolved thereby.
The stock h. is tubular and passes over the bearing f. and is secured by the
screw at 3, and in this stock h. there is a cross hole or opening either at right
angles or at an inclination to the shaft a.
The drill or tool d. is received within the chuck e. the end portion 4. of which
is split longitudinally at two or more places and it is conical and provided with a
screw thread 5. at its upper end,
There is a tubular shatt i. formed with or attached to the bevel-gear c. and this
shaft is made with a conical end 6. setting into the side of the stock h. which is
recessed for its reception so that this conical portion 6, forms a bearing that receives
the pressure when the drill or tool is pressed to its work.
In order to hold this tubular shaft in place I introduce at the other end the
conical collar n. forming a bearing against the stock h. and the nut o. screwed upon
the tubular chuck e. holds the parts in place and also causes the chuck to grasp
and hold the tool,

page_text: The tubular shaft i, and chuck e, and the collar n. must all turn together and
the rotation must not tend to loosen the nut o.
To effect these objects I introduce a pin 8, in the tube of the chuck, the outer
end of which passes into a notch at the upper end of the tubular shaft i. and into
a notch in the eye of the washer or bearing n. and the inner end of this pin 8.
projects within the tubular chuck e. and the inner end of the tool d. is removed at
one side to pass by the pin and formed with a notch at r. so that after the tool
has been inserted into the chuck it is partially rotated to bring the notch r. to the
pin 8. and then the nut o. is screwed up to tighten the chuck.
The chuck centers and holds the tool tightly and the pin 8. and notch r. prevent
the tool being drawn out if the chuck should become loose and the pin insures the
rotation of the tool by the revolution of the gear c. and tubular shaft i.
It will be apparent that this improved angle attachment is adapted to dental
drills and tools of any description and that the parts are very compact and
reliable.
It is usually preferable to employ the cap v. hinged at 9. to the stock h. and
kept down by a spring catch at 10. so as to prevent the rotating nut o. coming into
contact with the mouth or any part of the person.
It will be apparent that in cases where it is not desired to clamp the tool, the
tube that receives the tool may be whole instead of being split at one end, and in
cases where the inner end of the nut is of the same shape as the conical washer,
such washer may be dispensed with or formed as one with the nut, the other parts
remaining the same.
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
First. The combination with the shaft a. the bevel gears and tool of the tubular
bearing f. for the shaft a. the screw 3. and the stock . screwed upon the tubular
bearing, substantially as set forth.
Second. The combination with the tubular shaft i the bevel gears and the tool,
of a tubular split chuck within the shaft adapted to receive, clamp and hold the
tool, substantially as set forth.
Third. The combination with the shaft a. bevel gears and the stock h. of a
tubular shaft having a conical bearing at one end, a conical washer surrounding
the other end, and a nut to secure the parts in place, substantially as set forth.
Fourth. The combination with the stock, shaft and bevel gears, of a tubular
shaft having a conical end bearing, a chuck within such shaft for holding the
tool, and a nut for closing the cbuck and clamping the tool, substantially as
set forth.
Fifth. The combination with the stock, shaft and bevel gears, of a tubular shaft
having an end bearing, a chuck within such shaft, a washer forining a bearing
against the stock and a nút to act upon the chuck and hold the tool, substantially
as specified.
Sixth. The tubular shaft having an end bearing, in combination with the beve!
gearing, the washer, the nut and a pin acting to ensure the rotation together of the
chuck, the tubular shaft, the washer and the tool, substantially as set forth.
Seventh. The combination with the angle attachment for dental engines
containing a clamping chuck and nut, of a movable cap covering the nut, substan-
tially as set forth.
Dated this 20th day of February 1885.