Improvements Machines for Cutting the Teeth of Wheels.
Year: 1897

page_text: Date of Application, 23rd Apr., 1897-Accepted, 4th Dec., 1897
COMPLETE SPECIFICATION..
Improvements Machines for Cutting the Teeth of Wheels.
I, FRANZ REGNER, of Pfersee, near Augsburg, Germany: Foreman, 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 subject matter of this invention is a cog-wheel planing machine, rendering
possible the production of involute and cycloidal gearings without template or model.
Hitherto, worm wheels, for instance, of small pitch only could be turned out
accurately, by means of shaping tools; but in the case of pitches of 25 millimetres and
upwards such tools cannot be used and disc cutters or so-called "cutting files " are
still used for this purpose. But the gearings turned out in this way have not a,
proper worm.
With the apparatus forming the subject of this invention, worm-wheels, up to the
largest pitch, can be made with any desired shape of cogging, without any template,
being planed by means of two planing tools, and in doing so every cog can be given
the exact screw pitch, with the greatest accuracy. The expensive cutters hitherto
used are altogether dispensed with.
Hitherto, on spur and bevel gear cutting machines, cogs could hitherto be planed,
with two planing tools, with the aid of templates or models only, but these cannot
be made accurately except by very efficient men; their production takes much time
and involves considerable expense. As already stated, with this new machine any
desired form of cogging can be planed by automatic action of the planing tools, to
the requisite curve, without any such template or model. In the drawing, the
arrangement for the production of the tooth curves is shown in general outline only,
as in the present invention, this only is in question. The arrangement for the
periodical shifting of the wheel to be worked, as well as that for the "under cutting"
(inside cutting) of the worm wheels, and for planing and making true the bottom of
the interstices between the teeth in the case of spur wheels, has been omitted here,.
as being foreign to the subject matter in question.
In the earlier part it was stated that the machine can plane involute and cycloidal
gearings, although in it, the planing tools are always moving in circular lines only;
this was said in view of the fact, which generally speaking, will be admitted as
correct, that on the one hand any small portion of an involute required for the
respective form of cogging may be replaced by a corresponding arc, coinciding with
the theoretical involute, and that, on the other hand, the cycloidal form of cogging
consists of two cycloidal curves, one above and one below the pitch line, and each of
which can be replaced by a corresponding circular arc.
Hence it appears that both involute and cycloidal coggings may be produced in
the form of ares pure and simple. The planing tools or headstocks are moved
automatically in this machine in such arc-lines.
Fig 1. of the drawing shows a front view,
Fio side view of the machine.

page_text: On the sliding carriage a which is adjusted according to the size of the cog-wheels,
guides b are fixed on either side on which the carriage C slides. On the latter,
a core-piece d is arranged adjustable in prismatic guides, so that it can be shifted on
the guides by a spindle e. On this core-piece, a lever g shaped after the style of a
sliding carriage, is arranged with liberty to revolve on a pivot f. On this lever g
again, a nut h is arranged so that it can be shifted, and by means of the screw
spindle adjusted. The nut h is connected by means of a rod with the head-
stock m which is free to slide on the slide q of the sliding carriage n.
In order to plane an involute gearing, approximated by means of corresponding
circular arcs, the nut h on the sliding carriage g is, in the first place, adjusted, with
reference to the pivot f, so that the distance between the two centres of f and h
correspond to the radius of the curves to be planed. This adjustment can be easily
and quickly made, with the aid of the graduation provided, on the lever g, and
a mark arranged on the nut.
The sliding carriage n is thereupon advanced, by means of the spindle o, towards
the wheel to be planed. As the sliding carriage C is now held fast by the spindle p,
the lever g (pivotted on f) will now by means of rod (which is borne at h with
liberty to revolve) shift the head-stock m with the planing tool r, on the slide 7, so
that slide rest m together with tool is moved in the direction of the two arrows
exactly in accordance with the arc for which the lever g has been set. This feeding
motion, of course, should only take place each time to the extent of the thickness of
a shaving (as cut off by the planing tool).
On the sliding carriage a, arranged in opposite directions, a second such
arrangement is provided, which serves for the simultaneous production of the
opposite curve of a second cog.
As the cutters r of the two arrangements, driven by the belt-pulley 8 (which
they have in common) are constantly revolving, they will accurately fashion the
cogs, or the clearings between the cogs, in accordance with the abovementioned
arc-lines.
These two arrangements are further provided with one arrangement each, by means
of which they can be moved so that the cutters may cut the small bottom-curve of
the cogging in question, or, in the case of cycloidal cogging, approximated by arcs,
the bottom curve, which is of the same size as the top curve.
k is a bed fixed on the sliding carriage a, and on which a sliding lever t rests,
with liberty to revolve on a pin ko. On a core-piece, adjustable by means of a
screw-spindle, and bearing a fixed pin u is arranged. In order to govern the two
cutters so that, after planing the involute curves or the top curve in the case of
cycloidal gearings, they may automatically change the direction of their motion so
as to snbsequently plane the bottom curve of one or the other, an adjustable cheek v
is screwed fast to the sliding carriage n so that, at the proper moment,-that is to say
after the proper curve has been planed, it will press against the pin u and thereby
cause the prismatic lever t to turn on its pivot.
To this levert a tooth segment w is fixed, which, while t is turning, will move
gearing of the spindle p, thus causing the latter to revolve. Through this revolution
the sliding carriage C is moved in the direction indicated by an arrow in dotted lines,
while at the same time the head-stock is moved by o in the direction towards the
cog-wheel to be planed; in this way the head-stock m is likewise moved in an arc
line, but in a previously opposite direction to that in which it moved before. By
previously opposite direction the curve underneath the "pitch-line" is meant,-
such as will occur in cycloidal gearings. In this case the tools r always continue to
work uniformly, and will work out the interstices between the teeth in exact
accordance with the arcs for which the apparatus is set.
16
This latter movement is easily accounted for, for as the carriage n is moved forward
and carriage C is being pushed inwards by spindle p, the head-stock m, being
connected with the former, is compelled to describe the arc line in question, and as
the tools are continually at work the desired interstices between the teeth will be cut
or planed out exactly. According to whether the pin is set nearer to, or further

page_text: from, the pivoting point of lever t, the motion of the spindle p will be accelerated or
retarded, and consequently the curve to be planed will have a larger or smaller
radius.
The cheeky serves for the purpose of moving back, on the head-stock m being
returned, the pin u to its original position.
Finally it should be noted that revolving planing cutters are used for planing
worm-wheels only. In the case of spur and bevel gears, the planing tools are given
the ordinary thrust motion, in executing which they are moved in corresponding
curves by the arrangement o p or g t.
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
A cog-wheel planing machine on which involutes and cycloidal types of cogs or
gearings, approximated by circular ares, are planed by two planing tools r, without
any templates by the two head-stocks of the tools being moved in accordance with
the curves to be planed, by levers g and t which are borne on pivots and adjustable
by means of screw spindles o and p.