Improvements in Hydraulic Presses.
Year: 1888

page_text: PROVISIONAL SPECIFICATION.
Improvements in Hydraulic Presses.
We, RALPH HART TWEDDELL of No. 14 Delahay Street, Westminster, in the County
of Middlesex, Engineer, JAMES PLATT and JOHN FIELDING both of the Atlas Iron
Works in the City and County of Gloucester, Engineers, do hereby declare the
nature of this invention to be as follows:-
When hydraulic presses are made with followers of large extent, such as are
employed for bending boiler or armour plates, it is usual to apply two, three or more
separate hydraulic cylinders to move such followers, but it is found difficult to make
all the plungers of these cylinders move equally so that the followers sometimes angle
themselves and do not apply a uniform pressure throughout the whole extent of the
object acted on.
Our invention relates to such a construction of hydraulic press that we can obtain
an equable movement of the follower and deliver uniform pressure throughout its
extent. For this purpose we employ a hydraulic cylinder with its axis at right
angles to the direction in which the follower has to move, and to the plunger of this
cylinder and to side rods extending back from the plunger on each side of the
cylinder we attach cross heads on each of which we mount a pair of rollers in contact
with each other and also with inclines fixed on the follower or on the stationary
framing or on both. As the plunger is moved outwards by the hydraulic pressure
these rollers rolling along the inclines push the follower in a direction at right
angles to the line of motion of the plunger, with a force depending on the inclination
along which the rollers run. When there are inclines as above described on the
stationary framing the crosshead is jointed to the hydraulic plunger by a thrust
connecting rod allowing for the lateral movement of the cross heads. The inclines
however may be made only on the follower, the rollers running in that case along
guides on the stationary framing which are parallel to the axis of the cylinder. The
Inclines may be curved so as to vary the force applied to the follower at different parts
C

page_text: of the stroke of the plunger. The follower and plunger may be drawn back by any
suitable means such as a small hydraulic cylinder or they may be caused to return by
gravity according as the press is arranged to have its follower moved horizontally
or vertically.
5000
ABEL & IMRAY,
Agents for the Applicants.
Improvements in Hydraulic Presses.
We, RALPH HART TWEDDELL of No 14 Delabay Street Westminster in the County
of Middlesex Engineer, JAMES PLATT and JOHN FIELDING both of the Atlas Iron
Works in the City and County of Gloucester, Engineers, 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 :-
When hydraulic presses are made with followers of large extent such as are
employed for bending boiler or armour plates it is usual to apply two three or more
separate hydraulic cylinders to move such followers but it is found difficult to make
all the plungers of these cylinders move equally so that the followers sometimes angle
themselves and do not apply a uniform pressure throughout the whole extent of the
object acted on.
Our invention relates to such a construction of hydraulic press that we can obtain
an equable movement of the follower and deliver uniform pressure throughout its
extent.
For this purpose we employ a hydraulic cylinder with its axis at right angles to the
direction in which the follower has to move and to the plunger at this cylinder
and to side rods extending back from the plunger on each side of the cylinder we
attach crossheads on each of which we mount a pair of rollers in contact with each
other and also with inclines fixed on the follower or on the stationary framing or
on both. As the plunger is moved outwards by the hydraulic pressure these rollers
rolling along the inclines push the follower in a direction at right angles to the line of
motion of the plunger with a travel and force depending on the inclination along
which the rollers run. When there are inclines as above described on the stationary
framing the crosshead is jointed to the hydraulic plunger by a thrust connecting rod
allowing for the lateral movement of the crossheads. The inclines however may be
made only on the follower the rollers running in that case along guides on the
stationary framing which are parallel to the axis of the cylinder. The inclines may

page_text: be curved so as to vary the force applied to the follower at different parts of the stroke
of the plunger. The follower and plunger may be drawn back by any suitable means
such as a small hydraulic cylinder or they may be caused to return by gravity
according as the press is arranged to have its follower moved horizontally or
vertically.
The accompaning drawings represent a press embodying this invention in form
applicable for bending plates Fig 1 is a side elevation Fig 2 is a sectional plan
on X X and Fig 3 is a part sectional plan on Y Y. The hydraulic cylinder A is in this
case vertical and its plunger is provided with a thrust connecting rod B which as the
plunger ascends pushes up a cross head C carrying on each side rollers. By side
links D this crosshead C is connected to a similar crosshead E below this crosshead
having also rollers on both sides. The rollers on the one side of both crossheads run
along inclined guides F on the fixed framing and along vertical guides G on the
follower H which is guided at the top along the upper frame and has rollers I at the
bottom running along the base. The plate to be bent is introduced in a vertical
attitude between the follower H and the fixed side frame K the faces of the follower
and the frame being made of the required curvature. L'are rests for the lower edge
of the plate. When the pressure in the cylinder A is relieved the plunger and the
crossheads C and E descend and pressure acting in a small drawback cylinder M the
plunger crosshead of which is connected by side rods N to the follower H draws back
the follower. The hydraulic cylinder A might lie horizontally under the follower H
which in that case would become retracted by its own weight, the plunger of A being
provided with a suitable drawback. Instead of the inclines F being on the fixed
framing they might be on the follower H the vertical guides C being on the framing.
Or there might be inclines on both the framing and the follower. Also instead of two
sets of crossheads and rollers there might be several sets distributing the strain over
the length of the follower. Although we have shewn in the drawings a press suited
for bending plates it is obvious that the follower and frame K might be provided with
shear blades for cutting plates or with punches and dies for punching a number of
holes in a plate interposed between them, for raising heavy weights or for other
purposes for which hydraulic presses are applicable. And obviously the hydraulic
cylinder might be vertical, the follower being horizontal, or both might be inclined
according to the conditions under which the press has to act.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
For making equably a follower of considerable length in a bydraulic press, the
combination of a hydraulic cylinder having its axis perpendicular to the line of motion
of the follower, crossheads moved by its plunger and rollers carried by the crossheads
and bearing against inclines which are arranged to distribute the strain over the
length of the follower substantially as described.
Dated this 15th day of November 1888.
ABEL & IMRAY,'
Agents for the Applicants.