Improvements in Apparatus for Making Pipes or Tubes of Uniform Sectional Area and Curvature.
Year: 1899

page_text: Date of Application, 28th Feb., 1899-Accepted, 13th May, 1899
COMPLETE DITUITIVATION.
[Communicated from abroad by BIRNEY CLARK BATCHELLER, of 1518, North 15th
Street, Philadelphia, Pennsylvania, United States of America, Mechanical
Engineer.]
Improvements in Apparatus for Making Pipes or Tubes of Uniform
Sectional Area and Curvature.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, 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:-
-
My invention relates to apparatus for rendering uniform the sectional curvature
of tubes, and primarily bent tubes of the kind used for pneumatic despatch
apparatus in which uniformity in sectional curvature is of the greatest importance
to the proper working of the system. It is of course almost impossible to bend a
tube without modifying its sectional curvature, and the object of my invention is
to provide means for restoring the tube to its normal and proper sectional cur-
vature without materially changing the lineal curvature and I have discovered
that this may be satisfactorily accomplished by the use of a number of expanding
devices each having but a small surface contact with the inside of the tube and
which, by reason of their function, I will call expanding mandrels being introduced
into the tube in series and driven forward therethrough by repeated light blows
communicated directly to the outermost expanding mandrel and through it to
the inner expanding mandrels all of which are in contact progressively. In this
way I am able not only to force the tube to the desired sectional curvature at any
given point but to maintain it at the desired curvature as the expanding pro-
gressively extends through the tube and I am able to do this without destructive
strains to the material of which the tube is composed by reason of the fact that
each blow is, compared to the strength of the material, a light one, and by reason
of the small contact of each mandrel with the tube the work of expanding at any
given point is comparatively small.
The nature of my invention and also certain features of advantageous construc-
tion in the devices and apparatus employed will be best understood as described in
connection with the drawings in which they are illustrated and in which
Figure 1 is a plan view illustrating the operation and apparatus used by me in
restoring a bent tube to its proper sectional curvature.
Figure 2 is a side elevation of the buttress against which one end of the pipe rests.
Figure 3 is an end elevation taken as on the section line 1—1 of Fig. 1.
Figure 4 is a side elevation of one of my expanding mandrels constructed as I
prefer to construct it and
Figure 5 is an end view of the same expanding mandrel.
A is a bent tube to be expanded or restored to proper sectional curvature and
which as shown I secure. in position to be operated upon by resting it upon
trestles BBB with its end abutted, as shown, against a supporting block D.
027

page_text: CC are fastenings of rope, each, as shown, wound round the pipe and anchored at
each end to some convenient anchorage; as shown, bolts CC etc., secured to the
floor. This, or an equivalent mode of securing the tube in place so that it will
have a certain power of yielding or springs under blows, is an important practical
feature of my construction, the cords permitting the pipe to yield slightly and
spring back to true position thus avoiding the shock which would be incident to
the rigid anchoring of the tube in position. E indicates my preferred form of
expanding mandrel made up, as best shown in Figs. 4 and 5, of two discs EE
having rounded edges, said dises being secured together by a stud as E2 and pre-
ferably provided at the centre of their outer faces with bosses E3 which when a
train, so to speak, of such mandrels are introduced into the tube, as shown in
Fig. 1, come in contact with each other. The particular advantage of the form of
expanding mandrel illustrated is that the two connected discs of course hold each
other in proper alignment and at substantially right angles to the centre line of
the pipe, while at the same time the construction' enables me to reduce the weight
of each mandrel to a low point and it is obviously very advantageous that the
weight of the mandrels shall be as light as possible so as to reduce their moment
of inertia. F is a frame or support in or upon which the power hammer G is
secured so as to be longitudinally adjustable. Preferably a pneumatic power
hammer of great speed of movement is employed, H indicating a hole by which
air is introduced to the hammer and the said hammer being made adjustable in
the frame as by means of an adjusting screw I. J indicates the piston rod of
the hammer having a head K, and L is a rod or bar through which the blow of
the head K of the hammer is transmitted to the outermost of the expanding man-
drels E. Of course the rod L may under certain conditions be secured to the
hammer but preferably it is rested against the boss E3 of the outer mandrel and
struck by the hammer.
As shown the train of mandrels E shown as situated in the pipe Fig. 1 are of
progressively large diameter and this is obviously advantageous and under some
conditions is practically necessary.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is:
1. An expanding mandrel for unifying the sectional curvature of tubes consisting
of two discs each having narrow rounded edges rigidly secured together by a stud.
2. An expanding mandrel for unifying the sectional curvature of tubes consisting
of two discs each having narrow rounded edges rigidly secured together by a stud
and having on their outer faces central bosses for receiving or transmitting impact
blows.
3. In an apparatus for unifying the sectional curvature of tubes, the combination
with means for anchoring the tube in place, of a power hammer, a frame in which
the hammer is adjustably secured, and a series of expanding mandrels, adapted
as described, to be driven through the anchored pipe by the repeated impact blows
of the hammer.
יהו.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.