Improvements in Testing Machines and Weighing Machines.
Year: 1891

page_text: Date of Application, 23rd Dec., 1891
Complete Specification Left, 23rd Sept., 1892-Accepted, 5th Nov., 1892
PROVISIONAL SPECIFICATION.
Improvements in Testing Machines and Weighing Machines.
I, JOSEPH HARTLEY WICKSTEED Machine Tool Maker Well House Foundry
Leeds, do hereby declare the nature of this invention to be as follows
The invention relates to traversing the poise upon the steel-yards of testing or
weighing machines. This I do by means of hydraulic, or other power, cylinders,
or cylinder in conjunction with counterweight which power acts through pulleys &
wire cords & attachments upon the poise in such a way that the working of the
apparatus can have no effect upon the balance of the steel yard, other than by
altering the position of the poise.
The cylinders, pulleys & counterweights are fixed & supported independently of
the steel yard & the force they exert upon the poise is conveyed through
horizontal cords which support their own weight & which are so attached to the
poise that they can bring no vertical pressure to bear upon the steel-yard. The
power for moving the poise may be applied at any desired speed by a regulating
valve worked by hand or a valve may be worked automatically by the steel-yard.
Dated this 23rd day of December 1891.
J. H. WICKSTEED.
COMPLETE SPECIFICATION.
Improvements in Testing Machines and Weighing Machines.
I, JOSEPH HARTLEY WICKSTEED Machine-tool Maker Well House Foundry
Leeds, 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 :-
The invention relates to traversing the poise upon the steel-yards of testing or
weighing machines. This I do by means of hydraulic, or other power, cylinders,
or cylinder in conjunction with counterweight which power acts through pulleys &
wire cords & attachments upon the poise in such a way that the working of the
apparatus can have no effect upon the balance of the steel yard, other than by
altering the position of the poise.
The cylinders, pulleys & counterweights are fixed & supported independently
of the steel-yard & the force they exert upon the poise is conveyed through
horizontal cords which support their own weight & which are so attached to the
poise that they can bring no vertical pressure to bear upon the steel-yard. The
power for moving the poise may be applied at any desired speed by a regulating
valve worked by hand, or a valve may be worked automatically by the steel-yard.
In the accompanying drawings
Figs. 1 & 2 shew respectively a side elevation & a plan, of an hydraulic cylinder
in conjunction with a counterweight acting through pulleys & wire cords &
attachments upon the poise of a testing machine steel-yard in my improved manner
& also shew an arrangement of valve which may be worked automatically by the
steel-yard.
Figs. 3. & 4 shew respectively in side & end elevation the details of the
attachments drawn. to a. larger scale.
Referring to Figs. 1 & 2. A. is the steel yard of a testing machine B is the
traversing poise C is an hydraulic cylinder, D D are a. pair of pulleys carried on a
crosshead which is thrust forward by the plunger of the hydraulic cylinder,
Price 87

page_text: E E are wire cords surrounding the pulleys & each attached at one end to a fixed
portion of the cylinder, & at the other end to the poise, by my improved
attachments.
G. G. are continuations of the cords from the poise, which pass over the
pulleys H. H. H. to the weight L, which weight is constantly straining the cords
taut against the hydraulic cylinder C & tending to draw the poise back along the
steel-yard whenever the hydraulic pressure is exhausted from the cylinder C.
My improvements would equally apply, if instead of a direct counterweight
being used to pull back the poise, a weight were used hung upon a snatch block &
so only travelling half the distance of the poise or if instead of either such
application of a weight a plunger were used working in an hydraulic cylinder under
constant pressure, but of only half the power of the cylinder C, or if instead of any
of the 3 foregoing methods, the cords were brought round in an endless circuit to
the cylinder C which would then be fitted with a double acting piston or with twò
single acting plungers instead of with the one single acting plunger described.
When counterweights are used the two cords G G are brought closely together
at their ends into the centre line of the counterweight, so that it is impossible for
the weight to descend more rapidly with one cord than with the other, & this
ensures that the poise shall traverse upon the steel-yard with its axis at all times
parallel with the axis of the steel-yard, for if from any frictional resistance opposing
the advance of the poise unequally at its two sides, it should tend to advance one
side beyond the other & get ascew with the beam or steel-yard so called, the result
would be that the forward moving side would have to lift the whole mass of the
counterweight & so would relieve the backward tending side from all back pull
from the counterweight & enable it easily to overcome the frictional resistance
retarding it & keep square across the steel-yard.
The extreme ends of the cords E. E are each independently attached to the
fixed portion of the cylinder & where they pass over the pulleys D. D. on the cross-
head, are equally prevented from moving one in advance of the other by having
the crosshead rigidly attached to the plunger of the hydraulic cylinder C &
not capable of swivelling thereupon. M. M. are hydraulic valves of ordinary
construction for regulating by hand the admission or exhaust of water from the
cylinder C by which the crosshead carrying the pulleys D. D. is thrust forward so
as to advance the poise, or is allowed to be drawn back by the counterweight L.
so as to retire the poise. N is an hydraulic valve of good ordinary construction
which is opened or closed by the rise or fall of the steel-yard either by means of
an ordinary tappet bar, or by its motion making or breaking an electric circuit or
circuits & thereby opening or closing the valve. The adjustment of the poise is
thus made automatic so that instead of regulating the admission of water to the
hydraulic cylinder by the hand valve M, that valve may be left open during the
test, or may be dispensed with & the admission or non-admission of water for
the advance of the poise, will be regulated automatically by the motion of the steel-
yard which will open the valve N whenever it rises above the horizontal line &
will close it whenever it drops below it.
Referring to Figs 3 & 4. The cords E. E. & G. G. by which the poise is
traversed are connected with it in the centre plane of its mass through a pair of
radius rods O. O. on each side of the poise, which hinge upon studs P. P. fixed in
the poise. The other ends of the radius rods O. O. are connected by a cross
bar F. the central axis of which describes a vertical line insomuch as it is a neutral
axis between the two ends which are attached to the radius rods & which describe
arcs in opposite directions whenever the poise moves vertically in relation to the
crossbar F.
To this central axis of F the wire cords are attached & it follows that the
poise can rise & fall vertically without encountering resistance from the taut
wire cord.
The wire cord is self supporting between its pulleys & is incapable of adding

page_text: weight to the poise because the axis of the crossbar of the parallel motion to
which it is attached can only resist horizontal forces & offers no resistance to
vertical forces.
The parallel motion as described consisting of crossbar & radius rods hinged
upon fixed studs in the poise, is counterbalanced by the small weight R. & so does
not rest any of its weight upon the wire cord. Its whole weight as counterbalanced
by R. together with the weight of R. rests upon the studs fixed in the poise & these
parts are weighed in at the adjustment of the poise to make up its standard of
weight. The parallel motion as described is in a state of neutral equilibrium &
therefore any sag of the cord which is attached to it can only depress the position
of the parallel motion but cannot rest any of its weight upon the poise.
Having now particularly described & ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. The novel feature of attaching to the poise of a steel yard, the parallel
motion mechanism as described so that cords may pull with any force horizontally
at the poise without impeding the vertical motion of the steel-yard, or bringing
any vertical force to bear upon it.
2. The novel feature of applying cords pulling in a direct central plane upon the
poise of a steel-yard, from pulleys fixed upon supports independent of the
steel yard.
3. The novel feature of drawing a poise along a steel yard by two parallel
cords, so connected at their ends either to fixed points or to the centre line of the
mass of a counterweight & so actuated by non swivelling crossheads, or crosshead
as described, that one cord cannot pull its side of the poise in advance of the side
pulled by the other cord.
4. The novel feature of adjusting the balancing position of a poise by an
hydraulic valve, opened & closed by the motion of the steel-yard itself, in
conjunction with the traversing apparatus described.
Dated this 22nd day of September 1892.
J. H. WICKSTEED.