Year: 1887

page_text: Date of Application, 19th Sept., 1887
Complete Left, 18th June, 1888
Complete Accepted, 20th July, 1888
I, EDWARD LYALL of Brownhills, near Walsall in the County of Stafford, Mining
Engineer, do hereby declare the nature of this invention to be as follows:-
The principal object of this invention is to provide a levelling staff which can be
increased in length by means of parts sliding upon each other and will afford
an unbroken series of figures irrespective of the amount of the alteration in
length.
Thus if constructed for extension from three to five feet six inches, by my
invention any intermediate amount of extension may be effected and the figures
displayed in their proper order.
Supposing the staff to be constructed in two parts one sliding in a groove at the
back of the other, the grooved portion being numbered and divided on its face from
zero up to say 3 feet the latter end of the staff being termed for convenience the top
of the bottom joint. To the top of the bottom joint is attached a tape rather more
than double the length of the second joint and upon this tape the scale is continued to
say 5 feet 6 inches. At each end of the second joint is a guide pulley and the tape
passes over the upper guide pulley, down the back of the joint, under the bottom guide
pulley and up between the sliding joint and the bottom joint, lying in the groove at
the back thereof and the end is fixed at the top of the bottom joint.
By sliding the second joint of the staff upwards the tape is exposed and forms a
continuation of the first part of the scale whilst by closing the two parts of the staff,
the lettered portion disappears behind the second or sliding joint. The whole tape
being in a state of tension longitudinally around the second joint and being also fixed
to the top of the bottom is merely paid off and taken up by the two guide pullies as
the sliding portion is moved to and fro.
To retain the sliding portion in any desired position a thumb screw may be
inserted through the side of the bottom joint or any convenient clamping device may
be employed.
It is not essential that the second joint of the staff should slide in a groove formed
in. the bottom joint what is really requisite being that it should be capable of being

page_text: moved along the other so as to form a prolongation thereof and display the figured
tape.
The tape itself may be of any suitable material either continuous or in separate
pieces say of wood or metal-attached to or formed into a continuous chain by links
or other means.
It is obvious that this invention is applicable to other measures than those herein
described.
I EDWARD LYALL of Brownhills, near Walsall in the County of Stafford, Mining
Engineer, 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 principal object of this invention is to provide a levelling staff which can
be increased in length by means of parts sliding upon each other and will afford
an unbroken series of figures irrespective of the amount of the alteration in
length.
Thus if constructed for extension from three feet to five feet six inches, by my
invention any intermediate amount of extension may be effected and the figures
displayed in their proper order.
Supposing the staff to be constructed in two parts one sliding in a groove at
the back of the other, the grooved portion being numbered and divided on its face
from zero up to say 3 feet the latter end of the staff being termed for convenience
the top of the bottom joint. To the top of the bottom joint is attached a tape
rather more than double the length of the second joint, and upon this tape the
scale is continued to say 5 fect 6 inches. At each end of the second joint is a
guide pulley and the tape passes over the upper guide pulley, down the back of
the second joint, under the bottom guide pulley and up between the sliding joint and
the bottom joint, lying in the groove at the back thereof, and the end is fixed at the
top of the bottom joint.
By sliding the second joint of the staff upwards the tape is exposed and forms a
continuation of the first part of the scale whilst by closing the two parts of the staff
the lettered portion of the said tape disappears behind the second or sliding joint.

page_text: The whole tape being in a state of tension longitudinally around the second joint and
being also fixed to the top of the bottom is merely paid off and taken up by the two
guide pulleys as the sliding portion is moved to and fro.
To retain the sliding portion in any desired position a thumb screw may be inserted
through the side of the bottom joint or any convenient clamping device may be
employed.
It is not essential that the second joint of the staff should slide in a groove formed
in the bottom joint what is really requisite being that it should be capable of being
moved along the other so as to form a prolongation thereof and display the figured
tape.
*The tape or band itself may be of any suitable material either continuous or in
separate pieces-say of wood or metal-attached to or formed into a continuous chain
by links or other means, it may be an endless band secured at the requisite point
to the primary joint, or a length having the two ends secured to the primary
joint.
These improved ineasuring instruments may be constructed of any desired length
and the scale markings thereon may be made to accord with any system of measure-
ment whether metric or otherwise.
In the accompanyings drawings:
Figures 1 and 2 are respectively a front and a back elevation of an instrument
constructed according to my present invention for measuring up to say four feet and
shewn in a partly extended condition.
Figure 3 is a longitudinal or vertical section of the same shewn, in full lines, as
partly extended and in dotted lines in a normal or closed condition.
Figure 4 is a transverse section of the same taken on the line A B figure 1.
Similar letters of reference indicate similar parts throughout the figures of
drawing.
a and b indicate the two parts or joints of the staff and c indicates the groove
at the back of the joint a. d, d, indicate guides or grooves formed at the sides of
the groove c for enabling the joint 6 to be slid up and down in the groove c.
e indicates the face of the joint a which face as shewn at Figure 1 is divided and
numbered as a scale up to two feet. f indicates the tape which is connected to
the upper end of the joint a and which as herein before described is rather more
than double the length of the sliding joint and the face of which is divided and
numbered as a scale from two up to four feet. 9, g, indicate the pulleys or rollers
which are carried in brackets 7, h, secured to the ends of the sliding joint 6 and
the lower of which is of less width than the upper. The tape f as shewn clearly
at figure 3 passes from the part at which it is fixed to a joint a upwards and over
the upper of the rollers g, thence down at the back of the joint 6, to, and under
the other roller and thence up in the groove c, and between the two joints a and b
and its second end is again connected to the upper end of the joint a, the portion
of the tape which never appears at the front of the instrument being as shewn
at Figures 2 and 4 in width less than that which does appear, so as to enable it
to move freely around the lower of the rollers 9, 9, and work freely in the groove_c.
i indicates the thumb screw by means of which the two joints a and b may be
temporarily secured together in any desired position relatively with each other.
As has been hereinbefore mentioned any suitable means other than that shown on
the drawing may be employed for prolonging the figured tape of beyond the upper end
of the joint a, and it is to be understood that the instrument may be constructed of
various lengths and that the flexible portion thereof may be composed of any
suitable material either continuous such for example as tape as hereinbefore described
or steel or brass band or they may each be made up of separate pieces say of wood
or metal, attached to or formed into a continuous chain by links or other equivalent
means.
To illustrate the advantage of the herein described measuring instrument and to
more clearly explain what is meant by the continuous reading of the measurements
indicated thereon it may be mentioned that in the case of an instrument of ordinary

page_text: construction for measuring up to four feet and formed in two parts which are
respectively divided and numbered as scales of from zero to two feet and from two to
four feet, that the scale measurements shewn upon the sliding joint thereof will read
continuously with those shewn upon the other joint only when the said sliding joint
is withdrawn to its fullest extent, for no matter to what extent the sliding joint is
withdrawn from the stationary joint, the top of the instrument will still indicate the
same as though four feet were measured, the true measurement only being arrived at
by deducting from the four feet limit the length of the sliding joint unexposed, that
is to say the part not drawn out from the stationary joint-In my measuring
instrument the measurements obtained no matter to what extent the sliding joint be
withdrawn still read continuously from zero up to the measurement desired.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is
1. In a measuring instrument such as described the obtaining of a continuous
reading by means of a band such as f fixed at the end of the bottom or primary joint
and passing round the ends of the top or movable joint whereby the said band can be
exhibited and withdrawn substantially in the manner and for the purpose described
and illustrated in the accompanying drawings.
2. The complete linear measuring instrument substantially as described and illus-
trated in the accompanying drawings.
:
Dated this 16th day of June 1888.
EDWARD LYALL