Improvements in Micrometer Wire and Plate Gauges.
Year: 1885

page_text: Improvements in Micrometer Wire and Plate Gauges.
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We, WILLIAM CROSS, of Loughborough in the County of Leicester, Mechanical
Engineer, and AMBROSE WOOTTON CROSS of the same place, Associate Member
of the Institution of Civil Engineers do hereby declare the nature of our inven-
tion for "IMPROVEMENTS IN MICROMETER, WIRE, AND PLATE "GAUGES to be as
follows:-
112-1
The object of our invention is to provide a cheap and efficient micrometer, or
measuring instrument that will instantly indicate on a dial, the thickness of wires,
plates or other articles, in thousandths of an inch or such other figures or gauges as
may be used or required for various purposes or trades.
&
For this purpose we construct an instrument or gauge having a fixed jaw and a.
movable jaw or slide; on one edge of the slide a series of teeth are cut or made so>
as to form a rack, which, in sliding, actuates or engages a pinion carrying on its
arbor a pointer or hand.
3
The sliding motion of the rack when the jaws are opened causes the pinion to
revolve, and the pointer indicates on a dial in thousandths of an inch, or such
other figures or gauges as may be marked on the dial, the amount of opening.
between the jaws, according to the thickness of the wire, plate or other article
placed between them.
'
j
A spring connected from a fixed part of the instrument to the sliding jaw, always,
keeps the jaws closed, or in contact with anything placed between them for.
measurement; the jaws are opened for use by sliding the movable jaw by means.
of a small thumb-stud attached to it for the purpose.
To prevent any back-lash, or play between the teeth of the rack and the leaves
or teeth of the pinion, (which play or back-lash would be fatal to the instruments.
usefulness or success as an accurate micrometer), we construct alongside of the rack,
and within a recess formed in the side of the slide, a small counter-rack which by
means of a small spring attached to the slide, acting in an opposite direction to the.
spring which closes the jaws, (above referred-to), is made to press on the leaves or :
teeth of the pinion and keep them always, in actual working contact with the rack
teeth on the sliding jaw, in spite of wear, thus preventing play or back-lash..
The working parts referred to above are enclosed in a suitable casing, with a
handle for holding the instrument when in use.

page_text: "
We WILLIAM CROSS and AMBROSE WOOTTON CROSs of 37 Leicester Road,
Loughborough in the County of Leicester do hereby declare the nature of this
invention, to be particularly described and ascertained in and by the following
statement:
-
The object of our invention is to provide a cheap and efficient micrometer or
measuring instrument that will instantly indicate on a dial the thickness of wires,
plates or other articles in thousandths of an inch or such other figures or gauges as
may be required for various purposes or trades.
In the accompanying drawings Figure 1 is a front elevation of the complete
instrument with part of the dial removed and a portion broken away to show the
mechanism. Figure 2 is a longitudinal section from front to back and Figure 2* is
a portion of the same on an enlarged scale. Figure 3 shows in detail on an
enlarged scale the main rack and Figure 4 the supplemental rack.
Like letters of reference represent like parts in all the views.
A is a frame or casing of any suitable shape but preferably circular to match
C is a fixed
the dial and having the handle B by which it is held while in use.
jaw forming part of or carried by the frame A and made of or faced with hardened
steel. D is a slide reduced at the centre of its length to about half the thickness
(as shewn in Figure 2). where it is formed into a toothed rack D¹ which gears with
the pinion E fixed upon the spindle F which carries the index hand G. The end D².
should be of hard steel as it forms the movable portion of the guaging jaw and
upon the other end of D is the projection H passing through a slot A¹ in the
casing A by which D is retracted. The spring I secured at one end, in the case A
and at the other entering the nick or slot D³ serves to keep D always pressed
outwards and the end D' pressed against the jaw C or against the object which is
being gauged and is for that purpose inserted between C and D.
The object of the supplemental rack K is to prevent play or back lash between
the teeth of the rack D and the leaves of the pinion E. The supplemental rack K
lies against rack D and its teeth coincide with those of D¹ and engage with the
same leaves of pinion E. The projecting faces K¹ slide in the slots D* and prevent
K from slipping back out of gear with E. The spring L secured in one end of K
fits against the shoulder D' and keeps the teeth of K firmly pressed against the
teeth of E which are thus pressed against the teeth of D¹ and all chances of looseness
or back lash by wear or bad fitting is avoided between E and D¹ and consequently
the index G can be relied on for a truthful reading. The rack K being carried
entirely by D moves with it without interfering with its movement.
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 iş:
1. In a micrometer gauge the combination with a sliding gauge such as D
pressed by spring I outwards towards the fixed jaw C and having a rack such

page_text: as D¹ engaging with the pinion E of a supplemental rack such as K also engaging
with pinion E against which its teeth press under the influence of a spring L and
carried by slide D substantially as and for the purpose specified.
2. The combination with a rack and pinion of a spring controlled supplemental
rack carried by the chief rack and gearing with the pinion substantially as and for
the purpose specified.
3. The complete instrument substantially as specified.