Improvements in and relating to Electric-welding or Metal-working Apparatus.
Year: 1890

page_text: Date of Application, 27th May, 1890-Accepted, 25th Oct., 1890
COMPLETE SPECIFICATION.
[Communicated from abroad by HERMANN LEMP, of 19, Allen Avenue, Lynn,
Massachusetts, United States of America, Electrical Engineer.]
Improvements in and relating to Electric-welding or Metal-working
Apparatus.
I, WILLIAM ROBERT 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 the construction of electric welding or metal working
apparatus in which the piece or pieces of metal to be welded, or otherwise operated
are held in suitable clamps or holders movable with relation to one another and are
heated at the part to be welded, upset or worked in any other manner, by means of
currents of great volume but low electro motive force supplied to the part or parts to
be heated from an induction coil or converter having a secondary of low resistance
and large cross section as compared with the primary.
My invention consists in an improved construction of and manner of mounting
and guiding the clamp slide or body which carries the movable clamp of the
apparatus.
In the accompanying drawings,
Figure 1 is a cross section through an apparatus containing my invention taken on
the line xx Figure 2.
Figure 2 is a side elevation of the apparatus.
Figure 3 is a plan of one end of the apparatus.
S, is the secondary of a transformer which has a primary conductor P, connected
with any source of alternating electric currents for the purpose of developing currents
in the secondary which may be supplied to the work to be heated through the clamping
or holding devices for the work. The secondary S, is shown as rectangular in
circumferential outline or shape and split or interrupted at the point i to prevent
the currents developed in it by the alternating current flowing in the primary wire P,
from flowing in short circuit. The primary wire P, lies in a groove in the side of the
secondary.
The iron core of the transformer, as indicated at C, C, is made of two bundles of
sheet-iron plates, the ends of which are adapted to match, as shown in Figure 1, and
are held in position by means of end-plates or frames D, D, bolted together. The
iron forms a magnetic circuit through the centre of the secondary and primary, as
shown, and around the outside thereof. Each bundle of sheet-iron plates is held
together by suitable bolts applied at c. The magnetic circuit or core of iron might.
be formed in other ways. When the groove is formed in the side of the secondary,
as shown, the primary may be wound on a suitable mould or form and then slipped into
place in the groove.
M, M³, indicate the two clamp bodies or rests in which the work to be welded or
otherwise treated, after heating by the electric current, is clamped and supported.
In the present instance I have shown the apparatus as employed for welding together
two pieces of wire or other conductor W, W. The clamp body or block M may rest
upon and be fastened to one end of the secondary bar or may be formed integral with
such bar. The clamp body M is made as a slide by which it may be moved towards
the opposite clamp body. For the purpose of moving such slide I may employ a
screw H, working in a cross-head I, which is guided on the bar K below and is
connected at the top to two bars L, extending rearwardly from the clamp slide or
body M. This clamp slide M has a V-shaped bearing, as shown, upon the seat or rest
in which it moves. The V-shaped rest is formed on one end of the secondary S, and

page_text: I preferably interpose between the slide and its bed or secondary bar S a series of rolls
or balls H, preferably of copper, which permit, the slide to move with the greatest
freedom, but do not interfere with the free conduction of electricity from the rest or
bed on the top of the secondary to the slide. The clamp slide might be held down to
its bed or guide by gravity, though I prefer to employ spring pressure for which
purpose I provide the clamp slide with the rollers R R that run beneath a projection
upon the secondary, forming a rail for them as indicated in Fig. 1, and are supported
on rods B, which pass down through said projections from the slide, and are provided
at their top with springs S that tend to pull the clamp slide down against its seat.
The rollers H might be sometimes omitted in small machines, but it is ordinarily
preferable to retain them. By this construction I not only cause the clamp slide to
be guided accurately, but permit it to move with great freedom. I also avoid the
difficulties which have been met with in previous forms of clamp slides for electric
welding apparatus which are liable to stick when expanded by the heating effect of
the electric current passing through them from the clamp bed. Not only by this
construction is there a large contact surface which will perfect itself by wear, but
any expansion in the clamp slide, or the seat therefor, will only result in raising the
movable part in a direction opposite to the spring pressure. By using the V-shaped
bearing I also facilitate the construction of the guide. I find in practice that an
electric current of great volume may be passed from the seat or bed to the slide
without any undue heating even though the rollers be employed.
I do not limit myself to any particular form of rollers, though I prefer to use rolls
in the form of cylinders, as indicated.
Any desired means may be employed for moving the one clamp towards the other.
Suitable devices for holding the work down in the clamp are employed as indicated.
The devices shown consist of a clamp lever A³, which is pressed down upon the work
by means of a lever A', pivoted eccentrically to the lever A³, but engaging with the
upper and lower sides thereof. A indicates a removable piece which may be replaced
by another having an upper surface fitted to a different shape or size of wire or
conductor W, when different kinds of work are to be done.
Having now particularly described and ascertained the nature of my invention
and in what manner the same is to be performed, as communicated to me by
my foreign correspondent 1 declare that what I claim is :-
1. In an electric welding or metal working apparatus, a clamp slide for the work
supported and guided on its bed and in electrical connection therewith by a V-shaped
bearing, as and for the purpose described.
2. The combination in an electric welding or metal working apparatus with a
clamp slide having a V-shaped bearing, of a downward pressure spring, as and for
the purpose described.
I
3. The combination with the conducting slide in an electric welding or metal
working apparatus, of a conducting slide-rest on which the slide bears by a
V-shaped. bearing, and interposed conducting cylindrical rods of copper, as and for
the purpose described.
Dated
of May 1000.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.