IN MEANS OR APPARATUS FOR ENABLING CHAINS ROPES, BARS OR THE LIKE TO SUSTAIN TENSILE STRAINS WHEN SUBJECT TO SHOCKS OR OTHER INEQUALITIES
Year: 1884

page_text: тельно Блащо WBCA
Ropes, Bars, or the like, to Sustai
Subject to Shocks or Inequalities of Load.
I, JAMES GEORGE LOCKWOOD of Stockton on Tees in the County of Durham
"IMPROVEMENTS
Engineer do hereby declare the nature of said Invention for
IN MEANS OR APPARATUS FOR ENABLING CHAINS ROPES, BARS OR THE LIKE TO
SUSTAIN TENSILE STRAINS WHEN SUBJECT TO SHOCKS OR OTHER INEQUALITIES
to be as follows :-
"
My Invention relates to means or apparatus for enabling chains, ropes, bars or
the like to sustain tensile strains due to shocks or other inequalities such as arise
when a uniform power of motion is applied to a variable resistance, as in the case
of hoisting weights, drawing piles, or an addition is suddenly made to a suspended
load, or the motion of a heavy body is abruptly checked or reversed.
In carrying out my Invention I connect a spiral spring or its equivalent to the
chain, rope, bars or the like employed in transmitting tensile strains between the
points of resistance, in such a way as to offer an elastic resistance in the case of
sudden variations in the tensile strains which would produce shocks resulting in
fractures or other injuries to chains or similar unyielding articles, and at the same
time to transfer the strain from the spring to the chain so as to relieve the spring
from continuing to sustain a load which would injure its elasticity for future
efforts. In order to effect this the spiral spring or its equivalent is secured at each
end to the chain (or the like) which continues past or through the said spring, the
portion of chain or the like between the points of connection with the spring being.
of aufficient length to remain slack when the spring is not extended, but is so
adjusted as to length, that when the spiral spring has reached the limit of its safe
extension the slack portion of the chain or the like is drawn tight and takes up the
strain and bears it conjointly with the spiral spring which is thus prevented from
extending further-By employing more than one spiral spring or their equivalents
placed one within another or otherwise suitably arranged one of which may be
called the principal spring and the others, auxilliary springs, the elastic resistance to
sudden variations of load instead of being derived entirely by one spiral spring
which extends so far and then shares its load with the intercepted portion of the
chain or the like as before described, may be derived from a combination of spiral
CD G31

page_text: springs so connected to the chain or the like, that when one spring has extended so
far, an auxilliary spring begins to extend, and so on until the strain reaches the
intercepted portion of the chain or the like as before described and all further
extension of the springs is prevented-In order to effect this each auxilliary spring
is connected to the chain or the like at any suitable points not between the points
of connection of the principal spring so as not to affect the intercepted or slack
portion of the chain or the like, this may be done by means of a chain or other
suitable means of connection from one or both ends of each auxilliary spring to the
principal chain or the like, the chain or connections of the auxilliary springs being
adjusted to different degrees of slackness, so that when the principal spring has
extended a certain distance the connections of an auxilliary spring are put in
tension which causes the auxilliary spring to extend as well as the principal spring
and so on until the portion of chain or the like between the ends of the principal
spring is put in tension and all further extension of the springs is prevented.
Doted this O6th dow of Nanambar 100%
.
Improvements in Means or Apparatus for Enabling Chains,
Ropes, Bars, or the like, to Sustain Tensile Strains when :
Subject to Shocks or Inequalities of Load.
:
I, JAMES GEORGE LOCKWOOD of Stockton-on-Tees in the County of Durham,
Engineer do hereby declare the nature of my invention for "IMPROVEMENTS IN
MEANS OR APPARATUS FOR ENABLING CHAINS, ROPES, BARS OR THE LIKE TO
SUSTAIN TENSILE STRAINS WHEN SUBJECT TO SHOCKS OR INEQUALITIES OF LOAD
"
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 means or appliances for relieving articles subject to
tensile strains such as chains, ropes, hawsers, wires or other similar articles from
shocks or injurious effects arising from sudden variations in the force with which
such tensile strains are applied as for instance when a uniform power of motion is
applied to a variable resistance as in the case of hoisting weights or drawing piles,
or when an addition is suddenly made to a suspended load or when the motion
imparted to a heavy body by means of a tensile strain or pull is abruptly checked
or reversed.

page_text: Chains ropes or other similar articles usually employed to transmit heavy tensile
strains or pulls may be regarded practically as incapable of offering an elastic
resistance when suddenly subjected to an additional tensile strain, and in con-
sequence are liable to break or suffer deterioration under a load which more
gradually applied would be well within their power of endurance at the same time
injurious shocks are liable to be transmitted to any machinery or apparatus to
which they are attached. In order to enable chains or other equivalent articles to
obviate such shocks by offering an elastic instead of a rigid or non elastic resistance
to sudden variations in the tensile strain or pull to which they are subjected,
I connect to the said Chain or other equavalent article at any one or more suitable
positions a spiral spring coiled up in any suitable manner so that a check chain or
its equivalent may be connected with the spring to take off the tensile strain before
the spiral spring has reached the limit beyond which it cannot be extended without
destroying its efficiency for future efforts.
The spiral springs employed for this purpose are preferably coiled to parallel or
barrel shaped forms the parallel form offering a greater resistance for a given
diameter of rod forming the coil, while in the barrel shaped form the resistance to
extension is more uniform through all the coils of the spring. It is of course
obvious that other ways of coiling the spring may be adopted if found to be
suitable for the object of my invention. In some cases two or more spiral springs
may be connected to operate together by placing a smaller or auxiliary spring inside
a larger or principal spring, so that when the principal spring has extended to a
certain distance the auxiliary spring will come into operation and increase the
elastic resistance by assisting the principal spring, this would be an advantage
where the rapid diminution in the resistance of a single spring as the extension
proceeds would be liable to cause a second shock when the check chain comes into
operation.
And in order that my Invention may be fully understood I will now proceed
particularly to describe the same and for that purpose shall refer to the accom-
panying drawings wherein like letters of reference are employed to indicate the
same parts in both the Figures.
Figure 1 illustrates in sectional view a spiral spring coiled to a barrel shape with
a check chain connected to it internally, Figure 2 illustrates in sectional view a
spiral spring coiled to a parallel shape with an auxiliary spring and check chain
internally connected to it. I have not thought it necessary to describe or illustrate
other forms in which the spring could be coiled so as to admit of the check chain
or its equivalent being connected with it according to my invention as from Figures 1
and 2 illustrating the way in which the appliance is constructed with spiral springs
coiled in the usual way and the description generally it will be readily understood
how a similar combination of a check chain or its equivalent with any suitable form
of coiled spring could be effected according to my invention.
a is the spiral spring the coil of which terminates at each end in an eye or ring a¹
so that the chain 6 or other article may be secured to it. To these rings or eyes a¹
are connected the check chain or its equivalent, the link c¹ being connected to the
eye a¹ at one end of the coil a and another link, or (as I prefer for facility of
construction) a shackle c' is connected to the eye a¹ at the other end of the coil a ;-
When a check chain is connected to the spiral spring a as shewn in Figure 1 the
links should be slack enough to allow of the spring a extending to a certain
distance when the links of the check chain become drawn tight and share the load
with the spring, the slackness of the links of the check chain when the spring is
compressed, is shown in Figure 1 by the distance between the letters d d, this being
the distance to which the spring a can extend, after which all further extension is
resisted by the check chain, When a spiral spring and check chain are employed
in combination as shown in figure 1, the elastic resistance of the spring rapidly
diminishes as the coils open consequently in some cases where the nature of the
tensile strain requires it, this diminution of the elastic resistance may be obviated
in the manner illustrated in Figure 2 where a smaller auxiliary spring e is shewn

page_text: internally connected to the larger or principal spring a by means of links or
shackles c the coil e of the spring terminating in a ring or eye e' at each end for
that purpose The links or shackles c connecting the springs e and a may be made
to a slack fit when the springs are in compression as shown by the letters d' d' so
that the principal spring a will extend that distance before the auxiliary spring e
will be brought into action. This distance may of course be adjusted to suit the
relative powers of resistance of the springs and the nature of the strains to which
they are to be subjected. In addition to the auxiliary spring e, a check_chain or
its equivalent must be provided as already described with reference to Figure 1,
and this check chain may be connected to the eyes or rings a¹ of the spring a or
to the eyes or rings e¹ of the spring e as shewn in Figure 2 or it may be connected
to the eye or ring a' of the spring a and to opposite eye or ring e¹ of the spring e
or in any suitable manner so as to restrict the extension of both springs to the
required limit.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be carried into effect I declare that
what I claim is
An appliance or means to enable chains, ropes or other equivalent articles subject
to tensile strains to offer an elastic resistance to variations of such tensile strains,
the said appliance consisting of a combination of one or more spiral springs with
or more check chains or their equivalents substantially as hereinbefore
described.
one
Dated the 24th day of August 1885.