Improvements in Apparatus for the Manufacture of Bent Cranks.
Year: 1890

page_text: Date of Application, 7th Oct., 1890
Complete Specification Left. 7th July, 1891-Accepted, 8th Aug., 1891
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for the Manufacture of Bent Cranks.
I, WILLIAM ROGER DAWE Nottingham Street, Sheffield, in the County of
York, Works Manager, do hereby declare the nature of my invention to be as
follows:-
In carrying out my invention I propose to use hydraulic pressure as the motive
power to operate the various parts of the apparatus.
I construct a bed plate in the form of a rectangular cross with unequal arms,
two long and two short ones, suitable slots being provided in them in which the dies
or slide blocks will move and be kept in their proper positions. At or about the
end of each arm fix a hydraulic cylinder (four in all) with rams to force
forward their respective dies or blocks, and the bar of material from which the
crank is to be made is held at each end between the heads of the rams upon
the long arms, the dies upon the short arms being opposite the centre of the bar on
each side.
The bar is supported against adjustable dies or blocks upon the long arms of the
bed plate arranged at equal or unequal distances from the centre line of the opposite
rams, the adjustment being made by distance pieces placed between the heads of
the rams and the adjustable blocks before mentioned.
These two adjustable blocks form two points of resistance between which the
crank is bent, and they are set far enough apart to allow the throw of the crank to
be made deeper than is required in the finished size.
One of the rams on the shorter arm is provided with a die block shaped to form
the inside (or throw) of the crank. It bears against the bar centrally between the
two adjustable blocks, and as the hydraulic pressure is applied to it so as to bend
the bar, the adjustable blocks move towards each other, by the simultaneous action
of the two end rams.
The ends of the bar are prevented assuming an angular position by means of
retaining blocks preferably in the form of rollers fixed in a suitable position at the
back of the bar.
When the crank has been thus far formed, the fourth ram is brought into
operation and brings its die to bear upon the crown of the crank, compressing the
extra material before mentioned into the crown, and completing the size and shape
of the crank.
ROBT. F. DRURY, Fel. Inst. P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant.
COMPLETE SPECIFICATION.
Improvements in Apparatus for the Manufacture of Bent Cranks.
I, WILLIAM ROGER DAWE, Nottingham Street, Sheffield, in the County of
York, Works Manager, 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 :-
In carrying out my invention I propose to use hydraulic pressure as the motive
power to operate the pressing tools used in bending the crank, and in the annexed
sheets of drawings I have illustrated the apparatus as constructed and successfully
DiQ7

page_text: the ngures in when they occur.
Fig. 1, is a plan of the apparatus with a shaft in position for bending.
Fig. 2, side view of support for end of shaft.
Fig. 3, side view of spacing block.
Fig. 4, enlarged plan of bending dies, closed.
Fig. 5, section of same showing bent crank.
I construct a strong metal bed plate A, preferably in the form of a rectangular
cross with unequal arms, two long ones marked A', A², and two short ones A³, A¹;
these constitute a suitable form of bed plate, but I do not bind myself to this
or any other particular configuration.
Longitudinal slots B, are made down the centre of the said arms, extending
towards the centre of the bed plate; these slots are to receive and guide the
dies or bending blocks C1, C2, C3, C4, and other auxiliary parts.
At or about the end of each arm of the bed plate, I fix a hydraulic
cylinder D, D, D³, D³, having rams E', E, E, E', which move towards the
centre in line with the arms of bedplate, and therefore towards each other in
pairs. The dies or bending blocks C1, C2, are adjusted in longitudinal position
to suit the width of the required crank, by means of removable spacing blocks F,
of various widths, see Fig. 3, which are placed in the slots B, as shown in Fig. 1 ;
the said dies are grooved on their faces to a half circle or thereabouts, as indicated
by dotted lines, or they may have removable concaved faces dovetailed into them,
to suit shafts of different diameters.
The outside die C³-and the inside die C, may be made either solid or
expansible; I have shown C, made in two parts, clearly seen in Fig. 4, and keyed
together by a gib and cotters G, passed through a lug H, on rack part; the parts
are separated to the desired degree by the insertion of a metal strip or strips
placed between them, and are secured in the head of the ram by the keys K, or
set screws, or like means. The side dies C, C², are placed at such a distance apart
as will allow the throw of the crank to be bent rather deeper than the required
size, or in other words that there will be rather more material in the bent portion
than is necessary to form the crank if simply bent.
The two parts marked I, 12, are adjustable sliding supports or carriers to carry
the shaft S, and retain its ends in position, during the operation of bending their
tendency being to assume an angular position, a side view of this appliance is given
in Fig. 2.
When the cotter J is withdrawn, the handle K, can be lowered, and a side
entrance obtained for the shaft, into the bearing L, the handle is then raised and
the cotter is replaced.
The pressure blocks M1, M2, by means of which the pressure of the rams is
transmitted to each end of the crank shaft, are adjusted in the slots to abut
upon the ends of the shaft S, either close to the carriers I, or at a little distance
behind them, the shaft being supported horizontally and centrally with the concave
grooves of the dies.
When the shaft to be operated upon is thus placed and supported in position by
the carriers I, and with the pressure blocks M, in contact with its ends, and the
face of the die C, also in contact with the shaft, then hydraulic pressure is applied
by the action of the three rams E, E, E, the die C, which is formed to the
finished size of the inside of the throw of crank, presses the shaft between the
dies C, C, which are approaching each other, the blocks M', M², also moving
forward and pressing against the ends of the shaft.
When the three dies have thus approached each other, and the crank or throw
is partly formed, the fourth die C, is brought into action, and compresses the
crown of the crank, forcing into it the excess of metal which I have previously
mentioned, and thus increasing the thickness where it is required for machining.
The pressure applied to the ends of the shaft, not only materially aids in the

page_text: formation of the crank, but prevents attenuation at the bends or corners, and is a
most important and essential feature in this invention.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is carried into practice, I declare that what I
claim is :-
1 An apparatus or machine for bending cranks, consisting of a bed plate
provided with four hydraulic cylinders and rams which move towards a common
centre, fitted with adjustable bending and pressing dies to form the crank; carriers
to support and retain the ends of crank shaft, and blocks for pressing against each
end of the shaft simultaneously, substantially as hereinbefore described, and
illustrated in the annexed drawings.
2 An apparatus for the manufacture of bent cranks, in which longitudinal
pressure is applied to the opposite ends of the crank shaft, during the operation of
bending the throw, for the purpose of preventing attenuation at the corners of the
cranked parts, substantially as hereinbefore described.
Dated the 6th day of July 1891.
ROBT. F. DRURY, Fel. Inst. P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant.