IMPROVEMENTS IN THE MEANS FOR SECURING FLANGE AND OTHER JOINTS, ALSO APPLICABLE FOR JOINTS OF DRIVING BANDS AND THE LIKE.
Year: 1875

page_text: LETTERS PATENT to Heinrich August Theodor Ehrhardt, of Duessel-
dorf, in the German Empire, for the Invention of "IMPROVEMENTS
IN THE MEANS FOR SECURING FLANGE AND OTHER JOINTS, ALSO APPLICABLE
FOR JOINTS OF DRIVING BANDS AND THE LIKE.'
Sealed the 25th February 1876, and dated the 17th December 1875.
PROVISIONAL SPECIFICATION left by the said Heinrich August
Theodor Ehrhardt at the Office of the Commissioners of Patents,
with his Petition, on the 17th December 1875.
I, HEINRICH AUGUST THEODOR .EHRHARDT, of Duesseldorf, in the
German Empire, do hereby declare the nature of the said .Invention
for "IMPROVEMENTS IN THE MEANS FOR SECURING FLANGE AND OTHER JOINTS,
ALSO APPLICABLE FOR JOINTS OF DRIVING BANDS AND THE LIKE," to be as
follows:-
My Invention consists in employing in place of bolts or screws for
securing together the flanges and other joints of metal tubes, boiler or
tank plates, metal cases, and the like, a steel cramp of a trough form,
which is made with the space between the edges of the trough some.

page_text: what smaller than the thickness of the two flanges which it has to
secure, so that on being sprung open and fitted over the said flanges
the said edges will nip the flanges firmly together, so as to make them
form a perfect joint. The said cramps may be of any convenient length
that will allow of their being readily sprung open; thus for the circular
flanges of pipes or tubes of moderate diameter the entire circumference
may be secured by four separate cramps, which in this case are formed
with a curvature in the direction of their length corresponding to the
curvature of the flange.
In order to afford a maximum amount of strength in the cramp with
a minimum amount of metal I form the back part thereof, constituting
the bottom of the trough, with corrugations in the direction transversely
to the trough.
To enable the cramp to be sprung open readily, I prefer to form the
edges of the trough with lips curved outwards, so that by inserting. into
these lips the ends of two levers hinged together as a pair of tongs, and
bringing the other ends of the levers together by hand or screw power,
.the
cramp will be sprung open; or in place of levers two jaws connected
by a screw, like the jaws of a vice, may be employed. For insuring a
water, air, or steam-tight joint between the flanges thus secured these
may be made with hollows in their meeting surfaces, in which is inserted
a ring or fillet of caoutchouc or copper, or other suitable soft metal or
packing material; or the flanges may be curved at their outer edges, so
as to overlap each other, the said caoutchouc or other packing being
inserted between such curved parts.
The said cramps may also be employed for joining together the ends
of driving bands for machinery or of travelling belts or webs. For this
purpose the cramps are by preference made with the nipping edges
approaching each other much nearer than the sides of the trough, so
that there is sufficient space inside the latter for the ends of the band or
belt when inserted between the nipping edges to be bent over the
inner side thereof, whereby a firmer holding of the ends will be
insured.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Heinrich August Theodor Ehrhardt in the Great
Seal Patent Office, on the 9th June 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HEINRICH :
AUGUST THEODOR EHRHARDT, of Duesseldorf, in the German Empire,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of December, in the
year of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Heinrich August Theodor
Ehrhardt, Her special license that I, the said Heinrich August Theodor
Ehrhardt, my executors, administrators, and assigns, or such others as
I, the said Heinrich August Theodor Ehrhardt, my executors, adminis-
trators, and assigns, should at any time agree with, and no others, from
time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE MEANS
FOR SECURING FLANGE AND OTHER JOINTS, ALSO APPLICABLE FOR JOINTS OF DRIVING
BANDS AND THE LIKE," upon the condition (amongst others) that I, the
said Heinrich August Theodor Ehrhardt, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Heinrich August Theodor Ehrhardt,
do hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascer-
tained in and by the following statement thereof, reference being had
to the accompanying Sheet of Drawings, and to the figures and letters
marked thereon, that is to say :-
<
My Invention consists in employing in place of bolts or screws for
securing together the flanges and other joints of metal tubes, boiler or
tank plates, metal cases, and the like, a steel cramp of a trough form-
:

page_text: .
which is made with the space between the edges of the trough some-
what smaller than the thickness of the two flanges which it has to
secure, so that on being sprung open and fitted over the said flanges the
said edges will nip the flanges firmly together, so as to make them form
a perject joint. The said cramps may be of any convenient length that
will allow of their being readily sprung open; thus for the circular
flanges of pipes or tubes of moderate diameter the entire circumference
may be secured by four separate cramps, which in this case are formed
with a curvature in the direction of their length corresponding to the
curvature of the flange.
· In order to afford a maximum amount of strength in the cramp with a
minimum amount of metal, I form the back part thereof, constituting
the bottom of the trough, with corrugations in the direction transversely.
to the trough.
To enable the cramp to be sprung open readily I prefer to form the
edges of the trough with lips curved outwards, so that by inserting into
these lips the ends of two levers hinged together as a pair of 'tongs, and
bringing the other ends of the levers together by hand or screw power,
the cramp will be sprung open; or in place of levers two jaws connected
by a screw, like the jaws of a vice, may be employed. For insuring a
water, air, or steam-tight joint between the flanges thus secured these
may be made with hollows in their meeting surfaces, in which is inserted
a ring or fillet of caoutchouc or copper, or other suitable soft metal or
packing material; or the flanges may be curved at their outer edges so
as to overlap each other, the said caoutchouc or other packing-being
inserted between such curved parts.
The said cramps may also be employed for joining together the ends
of driving bands for machinery or of travelling belts or webs. For this
purpose the cramps are by preference made with the nipping edges
approaching each other much nearer than the sides of the trough,
so that there is sufficient space inside the latter for the ends of the
band or belt when inserted between the nipping edges to be bent over
the inner side thereof, whereby a firmer holding of the ends will be
insured.

page_text: of a pipe. Fig. 1 shews a side view, partly in section, of the ends of
two pipes, the flanges of which are secured together by four such
cramps; and Fig. 2 shews an end view, with the cramps partly in
section. The steel trough-shaped cramps A are in this case made of a
curved form, corresponding with the curvature of the pipe flange, four
such cramps being conveniently used, as shewn, for securing the entire
circumference of the flanges of moderate sized pipes, but a greater or
less number may of course be employed.
The edges a, a, of the cramp being made with a less space between
them than the united thicknesses of the flanges to be joined, they are
sprung open either by hand or by means of instruments, such as are
shewn at Figs. 15 to 17, in order to enable them to be fitted over
the flanges B, B, of the pipe, which they hold with an elastic force,
corresponding in intensity to the strength of the steel and the extent to
which they are sprung open.
To facilitate the opening out of the cramps they are by preference.
formed with curved lips a¹, a¹, into which the jaws of the expanding
instrument are inserted, as indicated at Figs. 15 and 17.
In order to afford a maximum holding power of the cramps with a
minimum amount of metal, I sometimes make them with the back.
corrugated, as shewn at Figs. 3 and 4, which represent respectively a
part sectional side view and part sectional end view of two pipe ends
secured together by such cramps. Here the cramp A is formed with
corrugations a at the back running in the direction of the length and
dying out towards the lips a, a, as indicated; or according to another
modification for increasing the strength of the cramp I arrange them
as shewn at Figs. 5, 6, and 7, which shew respectively a plan, a section
on line X, X, and a section on line Y, Y. In this case the steel cramp A
has fitted upon it one or more other cramps A¹, A', which may or may
not be formed with strengthening flanges a³, and which are slid on to A
from the ends thereof, the back of the cramp A being by preference.
made to taper slightly from either its middle towards each end, as shewn
at Fig. 7, or from the one end towards the other, so that A¹ may be.
made to nip A more or less by driving the former to a greater or less
extent on to the latter.
Figs. 8 to 11 shew various adaptations of the cramp for securing.

page_text: formed to receive packing rings D of plastic or elastic material between
them, which is compressed by the application of the cramps A, A, so as
to form a fluid or gas-tight joint, the cramps being made with corru-
gations a³, as already explained. Fig. 10 shews a side view, and Fig. 11
a cross section of a straight cramp A, adapted for securing the lids or
sides of metal cases E, these being formed with projecting rims or
flanges, which may either be curved, as shewn at e, with packing inserted
between them, or they may be flat.
Figs. 12 to 14 shew the application of the cramp A for securing
together the two ends of a driving or travelling belt, strap, or band F. :
Fig. 12 shews a cross section; Fig. 13 shews a side view, partly in
section; and Fig. 14 shews a plan. The cramp A. being expanded by
the tongs G, as shewn at Fig. 15, the two ends of the belt F are inserted
sufficiently for them to turn over to each side, so that on releasing the
cramp by unscrewing the nut g of the tongs G the cramp will securely
nip the two ends of the strap together.
Fig. 16 shews a plan, and Fig. 17 shews a side view of an instru- .
ment H, suitable for expanding the cramps when these are of considerable
length and strength, the jaws h, h, being inserted into the lips a¹ of the
cramp A, and the jaws h¹ then made to recede from 7 by turning the
nuts h². h³ is a handle for conveniently holding the instrument and
cramp.
Fig. 18 shews an instrument I, which may in some cases be useful for
forcing the two flanges B, B, of a pipe together before putting on the
cramps. It consists of two levers I, I, hinged together at i, and moved
to or from each other at their other ends by a right and left handed
screw .K, K, are cushions that are made to press against the flanges B
so as to force them together by the action of the screw i¹.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I wish it to be understood that I
made no claim to the before-described instruments for expanding the
cramps or pressing together the flanges, but what I claim is,-
First. The use of a steel trough-shaped spring cramp for securing
together flanges by the pressure of its lips or edges when somewhat
expanded, substantially as herein described.
Second. The use of a steel trough-shaped spring cramp for securing

page_text: together circular flanges, formed with a longitudinal curvature corre-
sponding to the curvature of the flanges, substantially as herein
described.
Third. The use of a steel trough-shaped cramp, having flanges with
projections or holes at its edges for facilitating the springing open of the
same, substantially as herein described.
Fourth. The use of a steel trough-shaped cramp having corrugations
formed on the back thereof, substantially as and for the purposes
described.
In witness whereof, I, the said Heinrich August Theodor Ehrhardt;
have hereunto set my hand and seal, this Second day of June, in
the year of our Lord One thousand eight hundred and seventy-
-six.