Improvements in Gauges for Cylindrical Surfaces and Screw Threads.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Gauges for Cylindrical Surfaces and Screw Threads.
I, GUSTAV ERNST, of Carl-Zeiss-Strasse, Jena, Grand-Duchy of Saxe-Weimar,
German Empire, Manager, do hereby declare the nature of this invention to be
as follows:
-
The invention relates to external and internal gauges for cylindrical surfaces
and screw threads. In manufacturing such gauges for purposes, where a high
degree of exactness is required, it has been found, that a substantial difficulty
arises from the fact, that by the process of hardening the dimensions of the gauge
are altered. To meet with this disadvantage I provide means for rectifying the
said alteration. For this purpose the external (annular) gauges or templets,
before being hardened, are tightly fitted in or upon an abutment of annular or
other suitable shape. Internal gauges or plugs. are made in a tubular shape
and likewise tightly fitted in or upon an abutment. Both kinds of gauges, after
being removed from their abutments, are hardened and then either fully split up
or only provided with incisions, both in an axial direction. Whilst this succes-
sive order of operations is preferable, it will be understood, that the gauges may
be slit up or provided with incisions before they are hardened. Finally the gauges
are refitted in or upon their abutments, suitable means being used to press them
tightly against the said abutments, so that the fitting surfaces of the gauge at one
side and the abutment at the other side are completely in contact and by conse-
quence thereof the gauge is reduced as nearly as possible to its former correct
size and shape. The said pressing means may consist in a ring, which is slit up.
and adapted to be contracted, if it surrounds the gauge, or expanded, if it is
inserted into the same, or which is fitted in or upon the gauge with a conical
surface and adapted to be employed as a wedge for pressing the gauge against the
abutment.
In the case of a gauge fully slit up the contact surfaces between the pressing
body just referred to and the gauge, or between the gauge and the abutment,
will preferably be formed as a screw thread for the purpose of more effectually
preventing those parts of the gauge which are separated by the slit from retaining
a displacement relatively to each other in an axial direction which might have
been caused by the hardening process. In some cases one single piece having at
least one conical pressure surface may represent the pressing body as well as the
abutment ring.
For the purpose of compensating for wear and tear the diameter of the improved
gauge may be made adjustable by employing an abutment, the effective diameter
of which can be altered at will. Such variation of the effective diameter is possible
with a conical or conically threaded abutment surface by varying the relative
positions of the gauge and the abutment in an axial direction or it may be attained
with a slit up annular abutment carrying means for expanding or contracting it.
Where one single body as above mentioned serves as an abutment and at the
same time by means of a conical surface presses the gauge against this abutment,
only a slight modification is required to enable the gauge to be adjusted after being

page_text: worn. For this purpose it will suffice to substitute an inclined spiral or cam
surface for the said conical surface. Then the gauge, which carries a correspond-
ing spiral surface cooperating with the first, will be expanded or contracted by
an angular displacement of both surfaces relatively to each other.
Dated this 22nd dow of Low 1900
Improvements in Gauges for Cylindrical Surfaces and Screw Threads.
1, GUSTAV ERNST, of Carl-Zeiss-Strasse, Jena, Grand-Duchy of Saxe-Weimar,
German Empire, Manager, 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 external and internal gauges for cylindrical surfaces
and screw threads. In manufacturing such gauges for purposes, where a high
degree of exactness is required, it has been found, that a substantial difficulty
arises from the fact, that by the process of hardening the dimensions of the gauge
are altered. To meet with this disadvantage I provide means to be
combined with the hardened gauge for rectifying the said alteration
For this purpose the external (annular) gauges oľ templets, before
being hardened, are tightly fitted in or upon an abutment of annular or
other suitable shape. Internal gauges or plugs are made in a tubular shape
and likewise while not yet being hardened-tightly fitted in or upon an
abutment. Both kinds of gauges, after being removed from their abutments,
are hardened and their either fully split up or only provided with incisions,
both in an axial direction. Whilst the successive order of operations
as described is preferable, it will be understood, that the gauges may
be slit up or provided with incisions before they are hardened. Finally the gauges
are refitted in or upon their abutments, suitable means being used to press them
tightly against the said abutments, so that the fitting surfaces of gauge and abut-
ment are completely in contact and by consequence thereof the testing surface,
which has been distorted by the hardening process, is reduced as nearly as possible
to its former correct size and shape. The gauge thus combined with its abutment
is ready for testing operations. The said pressing means may consist in a ring,
which is slit up and adapted to be contracted, if it, surrounds the gauge, or
expanded, if it is inserted into the same, or which is fitted in or upon the gauge
with a conical surface and adapted to be employed as a wedge for pressing the
gare against the abutment.
In the case of a gauge fully slit up the contact surfaces between the pressure
body just referred to and the gauge, or between the gauge and the abutment,
will preferably be formed as a screw thread (hereinafter called the locking thread)
for the purpose of more effectually preventing those parts of the gauge which are
separated by the slit from retaining a displacement relatively to each other in an
axial direction which might have been caused by the hardening process.
In the accompanying drawing:-
Fig. 1 is an axial section through an external thread gauge constructed accord-
in to the present invention.
Fig. 2 is a plan view of the gauge of Fig. 1.
Fig. 3 is an axial section through another external. thread gauge.
Fig. 4 is an axial section through a third external thread gauge.
Fig. 5 is an axial section through a fourth external thread gauge.

page_text: Fig. 6 is an axial section through an internal thread gauge.
Fig. 7 is an axial section through a fifth external thread gauge.
Fig. 8 is an axial section through a second internal thread gauge.
Fig. 9 is a plan view of the gauge of Fig. 8.
Fig. 10 is an axial section through a third internal thread gauge.
In the external thread gauge, which is represented in Fig. 1 and 2, the annular
gauge body a carrying the gauge thread a is slit up and surrounds the abutment
ring b, being tightly pressed upon the same by means of a pressure ring c, which
is likewise slit up and engages as a nut with the locking thread a¹ of the gauge
body a A screw serves to contract the pressure ring c.
Fig. 3 shows the abutment ring as screwed into the locking thread a¹ of the
gauge ring a. The pressure ring c is tapering and adapted to be forced over the
slit up gauge ring a by means of a nut d, which may be supported by the gauge
ring a or as shown by the abutment body b.
In the modified gauge shown in Fig. 4 the locking thread has become dispensable,
as the enhanced taper of the pressure ring chas a similar effect. It will be
remarked, that in this example the screw thread d between the abutment body b
and the pressure ring c corresponds to the separate screw d in Fig. 1 and 2 and
to the separate nut d in Fig. 3.
Only two pieces compose the external gauge represented in Fig. 5. The abut-
ment body engages with the gauge ring a by means of the locking thread a',
which in this case also serves as the thread of Fig. 4, as it enables the tapering
pressure ring c, which is integral with the abutment 6, to be forced into the gauge
body a.
In the internal gauge shown in Fig. 6 the abutment 6 and the pressure ring c
are again formed in one piece. The gauge body a and the said piece i c engage
with each other by means of an annular wedge formed on the gauge body and
having outwardly a conical abutment surface and inwardly a conical pressure
surface. It will be understood, that also the interior wedge surface might be
imagined to be the abutment and the exterior the pressure surface and that in
both cases a cylindrical abutment surface might be substituted for the conical one.
Four longitudinal incisions enable the threaded end of the gauge body to yield
under the double wedge action of the pressure and abutment body b c.
The pres-
sure device is completed by a screw d, the head of which is supported by the gauge
body.
For the purpose of compensating for wear.and tear the diameter of the improved
gauge may be made adjustable by employing an abutment, the effective diameter
of which can be altered at will. Such variation of the effective diameter is possible
with a conical or conically threaded abutment surface by varying the relative
positions of the gauge and the abutment in an axial direction or it may be attained
with a slit up annular abutment carrying means for expanding or contracting it.
Fig. 7 represents a first example of such an adjustable gauge. The locking
thread a¹, by means of which the abutment b and the gauge ring a are joined
together, is conical, so that the diameter of the gauge ring varies according as the
abutment 6 has been screwed to a less or greater extent into the gauge ring, before
contracting the pressure ring c by means of the screw.
The adjustable internal gauge of Fig. 8 and 9 is likewise constructed with a
conical locking thread a¹ between the gauge ring a and the abutment body b. The
screw serves to expand the gauge ring a by means of the conical outer surface
of the pressure disk c.
Where one single body as above mentioned serves as an abutment and at the
same time by means of a conical surface presses the gauge against this abutment,
only a slight modification is required to enable the gauge to be adjusted after
being worn. For this purpose it will suffice to substitute an inclined spiral or
cam surface for the said conical surface. Then the gauge, which carries a corre-
sponding spiral surface cooperating with the first, will be expanded or contracted
by an angular displacement of both surfaces relatively to each other.

page_text: An adjustable internal gauge of this kind is shown in Fig. 10. It may be
derived in the manner just explained from the gauge of Fig. 6. The diameter of
the gauge thread a differs with the angular position, in which by means of the
screw the spiral rib of the disk is pressed into the yielding spiral groove pro-
vided on the front wall of the gauge body a.
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
1. The combination with a diametrically yielding gauge body, of an abutment
body concentrically fitted together with the said gauge body and means for press-
ing the gauge body in diametrical directions against the abutment body, sub-
stantially as described.
2. The combination with a diametrically yielding gauge ring, of an abutment
body and a pressure body, one of which is fitted together with an inner circum-
ferential surface of the gauge ring and the other with an outer circumferential
surface of this ring, and means for varying the effective diameter of the contact
surface, by which the pressure body acts on the gauge ring, substantially as
described.
3. The combination with a fully split up gauge ring, of an abutment body,
means for pressing the gauge ring in diametrical directions against the abutment
body and a circumferential locking thread on the gauge ring connecting this ring
with a correspondingly threaded part of the total gauge, substantially as and for
the purpose set forth."
4. The combination with a diametrically yielding gauge ring, of an abutment
body and a pressure body, one of which is fitted together with an inner circum-
ferential surface of the gauge ring and the other with an outer circumferential
surface of this ring, and means for separately varying the effective diameter of
each of the two surfaces, by which the abutment body and the pressure body are
in contact with the said circumferential surfaces of the gauge ring, substantially
as and for the purpose set forth.
5. The combination with a diametrically yielding gauge body, of an abutment
body having a spiral rib adapted to enter a spiral groove on the gauge body, and
means for pressing the gauge body against the abutment body at different relative
positions of both bodies, substantially as described.
Dated this 18th day of October 1899.