An Improved Apparatus for Adjusting Surveyor's Measuring Chains and Steel Tapes.
Year: 1893

page_text: Date of Application, 5th Dec., 1893-Accepted, 20th Jan., 1894
COMPLETE SPECIFICATION.
An Improved Apparatus for Adjusting Surveyor's Measuring Chains
and Steel Tapes.
We, EDWIN PARNELL MUNTZ, of Winter Street Malvern in the Colony of
Victoria, Surveyor, HENRY LITTLEJOHN, of Gellibrand Street, Kew, in the said
colony, Surveyor, and LINDSAY RUSSELL, of "Aberfoyle" Kingsley Street,
Camberwell in the said colony, Surveyor, 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 object of this invention is to provide a simple and inexpensive apparatus
which will enable variations in the length of surveyor's measuring chains and steel
tapes to be readily adjusted, so as to compensate for permanent alterations in the
length of such chains and tapes by breakage or otherwise, and also so as to com-
pensate for the temporary, variations in their length by reason of the changes in
temperature.
The apparatus consists of a frame, preferably of gun metal made in two parts
connected together by guide rods and a right and left hand screw-threaded spindle
fitted with a small capstan nut, one of said parts having either a handle, as is usual
on the ends of surveyor's chains, or else an eye-bolt, to which a spring balance may
be connected, to ensure a certain strain being put upon the chain. This part of
the apparatus can be used by itself if so preferred.
At the opposite end of the other part of said frame is a longitudinally sliding bar,
having a screw-threaded spindle at one end working inside a long thumb nut let
into said frame, and thus prevented from moving endwise. The outer end of this
sliding bar is fitted with an eye-bolt, to which the end of the chain or tape is
secured, preferably through the medium of a spring hook.
A scale is marked on one side of the slot in the main frame in which the sliding
bar works, to indicate the amount of adjustment required in order to provide for
the variations in the temperature.
Having now generally described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we will proceed to more
particularly describe the same with the aid of the accompanying drawings,
wherein
Figure 1 is a plan, and
Figure 2 a side elevation of our improved apparatus for adjusting surveyor's
measuring chains and steel tapes.
Figure 3 is a plan (drawn to a smaller scale) of said apparatus applied to the end
of a surveyor's steel tape.
Figures 4, 5, and 6 are cross sections on the respective lines 4-4,5-5, and 6-6
in Figure 1.
Figure 7 is a plan of that part of said apparatus which can be used separately for
the permanent adjustment of the chain to correct mechanical variations."
The same letters of reference indicate the same parts in all the figures.
A represents the main frame or body of the apparatus, said frame or body
being made by preference of cast gun-metal, whilst B represents that part of the
end of said body or framing which is separate therefrom but which is connected
thereto by the right and left-hand screw-threaded spindle C, having a capstan
nut C' the screw-threaded ends of said spindle being arranged to work in corre-
sponding holes in the fixed and movable parts of the frame A.
The adjustable part B of the frame is fitted with two guide rods b, each working
in holes in the main frame A. D represents the sliding bar which is arranged

page_text: to work to and fro in a slot d formed for the purpose in the frame A, said sliding
bar being fitted with an eye-bolt e, with which a spring hook e¹ upon the end of the
chain or tape E can be readily connected or disconnected. represents a screw-
threaded spindle which is formed upon or secured to the sliding bar D, and which
passes through a correspondingly threaded thumb nut d2 working within the main
frame A. indicates a graduated scale, marked on the face of one side of the
slot d, whilst a represents a small arrow or pointer which is marked upon the face
of the sliding bar D, and which, with the scale, serves to indicate the position into
which the bar should be moved in order to compensate for the expansion and
contraction of the chain or tape caused by the variations in the temperature.
With an apparatus such as we have described, the length of the surveyor's chain
or steel tape can be readily adjusted, as will be well understood. Any difference in
such length caused by difference in temperature can be temporarily adjusted by
rotating the nut d² until the arrow d on the sliding bar D is brought into its correct
position opposite the scale d³, whilst any mechanical variation in the length of
the chain can be permanently adjusted by turning the capstan nut C¹ in the required
direction.
If preferred, the mechanical differences adjuster can be used separately, as
illustrated in Figure 7.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
First. The herein described apparatus for adjusting surveyors' measuring chains
and steel tapes, consisting of the various parts constructed arranged and operating
substantially as and for the purposes herein described and explained and as illus-
trated in the accompanying drawings.
Second. In an apparatus for adjusting surveyor's measuring chains and steel
tapes, a frame having one part adapted to be moved to and fro by means of a right
and left hand screw-threaded spindle (such as C) and being fitted with a sliding
bar (such as D) connected at one end to a tape or chain and actuated by a thumb
nut (such as d) the whole being constructed and arranged substantially as and for
the purposes herein described and explained and as illustrated in the accompanying
drawings.
Third. In apparatus for adjusting surveyor's measuring chains and steel tapes, a
frame made in two parts (such as A-B) connected together by guide rods and a
right and left hand screw-threaded spindle (such as C) substantially as and for the
purpose herein described and explained and as illustrated in the accompanying
drawings.
Fourth.. In apparatus for adjusting surveyor's measuring chains and steel tapes,
a frame (such as A) fitted with a sliding bar (such as D) connected. to one end of
the chain or tape and having a screw-threaded spindle (such as d¹) fitting into a
thumb nut (such as d) working within such frame, substantially as and for the
purposes herein described and explained and as illustrated in the accompanying
drawings.
Dated this Twenty-sixth day of October One thousand eight hundred and
nuetr thuon
nmate-thuon
E. P. MUNTZ.
H. LITTLEJOHN.
LINDSAY RUSSELL.
Harris & Mills,
23, Southampton Buildings, London, W.C., Agents.