IMPROVEMENTS IN MACHINES FOR TESTING THE STRENGTH OF CHAINS AND CABLES, AND FOR OTHER LIKE PURPOSES
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by James Tangye at the Office of
the Commissioners of Patents, with his Petition, on the 15th May
1865.
I, JAMES TANGYE, of the Firm of Tangye, Brothers, and Price, of Bir-
mingham, in the County of Warwick, Manufacturers, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN MACHINES FOR TESTING
THE STRENGTH OF CHAINS AND CABLES, AND FOR OTHER LIKE PURPOSES," to be as
follows:-
My Invention consists of the improvements herein-after explained in con-
structing and arranging the parts of machines for testing the strength of
chains and cables, and for other like purposes. The power ordinarily employed
for producing tension in the chain or cable to be tested is that of the ordinary
hydraulic press, and the machine for measuring and registering the tension to
which the chain or cable is subjected is connected to the cylinder of the
hydraulic press by means of a pipe. I arrange the parts of the testing
machine as follows:-The pressure in the cylinder of the hydraulic press is
communicated to a small cylinder forming part of the testing and registering
machine, and acts upon a piston in the said small cylinder. The top of the
piston rod of the said small cylinder is connected by means of a chain to a
quadrant fixed on the top of a rod, weighted at bottom, and capable of
vibrating as a pendulum; or the piston rod of the said small cylinder may be
connected to the said chain by means of a multiplying lever, instead of being
connected directly therewith. The pressure in the hydraulic press is trans-
mitted to the said pendulum, which is deflected from a vertical position until

page_text: the weight is raised so high as to balance the pressure to be measured. At
the back of the pendulum are two vertical graduated quadrants, both struck
from the centre on which the pendulum moves. The larger quadrant is fixed,
the smaller one is capable of moving upon the pendulum centre. Each of
the quadrants is graduated, and has a slot in it, in which a pointer slides.
Pins on the pendulum rod pass through the slots in the quadrants. As the
pendulum moves from a vertical towards a horizontal position, the pin in the
slot on the lower quadrant pushes the pointer before it as it rises, and when
by the breaking of the chain or otherwise the pendulum falls, the pointer is
left at the highest point it has been raised to in the slot in the quadrant, and
thereby registers on the graduation the maximum pressure which had been
attained. The object of the second or smaller quadrant is to signal when any
given pressure has been attained. The top of this quadrant is connected by
a link or chain to a weighted horizontal lever, the short arm of which has a
tooth, with which when the lever is in a horizontal position the spring hammer
of a bell engages. When the long arm of the lever is raised the hammer is
disengaged, and strikes the bell, and thus indicates when the required pressure
has been attained. In order to effect the lifting of the lever and ringing of
the bell at any required pressure, the pointer in the slot of the small quadrant
is made capable of being fixed at any part of the said slot. As the pendulum
rises the pin on the pendulum rod which traverses the slot in the small
quadrant moves freely in the said slot until it comes to the part at which the
pointer is fixed, when it raises the said pointer, and with it the quadrant, and
thus raises the lever connected to the quadrant. The arrangement last
described may be used for shutting off the hydraulic power when the required
pressure has been attained by raising or keeping open the suction valves of
the pumps..