Improvements in Slide Bevels.
Year: 1898

page_text: Date of Application, 14th Nov., 1898-Accepted, 10th Dec., 1898
COMPLETE SPECIFICATION.
Improvements in Slide Bevels.
I, CHRISTOPHER DAVID BEVAN, of No. 8, Stanley Terrace, Mount Pleasant, in
the Town and Borough of Swansea, in the County of Glamorganshire, Wood-
work-Instructor, 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:-
My invention relates to improvements in slide bevels, and has for its object
the construction of a slide bevel of greater efficiency than has hitherto been
attained which, firstly, when used for marking the bevels of roof timbers and like
purposes can be set to the required angle quicker and easier than a bevel of
ordinary construction, secondly, where the top and bottom angles of roof
timbers and like objects differ, will obviate the necessity of using two bevels to
mark such different angles, thirdly, the construction of a form of slide bevel
by which the length of roof timbers and like oblique objects can be obtained in a
simple and speedy manner.
In order that my invention may be clearly rendered, reference may be had to
the accompanying sheets of drawings.
Fig. 1, Sheet 1, shows a side elevation of a roof truss, with a slide-bevel such
as I shall describe, in a similar position to that in which it is placed when it
is used.
In this Sheet, No. 1, the following letters have reference:
-
A and B are the two respective halves of the roof truss divided by a central
vertical line.
CD, the dividing central vertical line.
E, the rafters.
FF, the tie-beam.
G, the bottom bevel or angle of the rafter.
H, the top bevel or angle of the rafter.
I, the right angle made by the line CD and the tie-beam FF.
J, the bevel in position. K, angle of blade.
The above letters are separate and distinct from the letters on Sheets Nos. 2
and 3.
Fig. 1, Sheet 2, shows an external view of one side of the bevel.
Fig. 2, Sheet 2, shows a sectional view of Fig. 1, Sheet 2, through the line de,
on an enlarged scale.
Fig. 3, Sheet 2, shows a plan view of the stock b Fig. 1.
In this Sheet, No. 2, the following letters have reference: -
a, the blade.
al, one face of the blade marked with standard inches and parts of inches.
a 2, the reverse side of the blade marked with feet and parts of feet according
to a scale on which one inch represents a foot.
b, the stock.
61, one face-edge of the stock marked with standard inches and parts of inches.

page_text: a scale on which one inch represents a foot.
c, screw clips or clamps.
de, section-line through Fig. 1.
f, the angle of the blade from which the measurements begin to count.
9, the strips of metal which keep the two halves of the stock apart.
Fig. 1, Sheet 3, shows an external view of the reverse side of the bevel shown
in Fig. 1, Sheet 2.
Fig. 2, Sheet 3, shows a portion of the face-edge of the stock, Fig. 3, Sheet 2.
on an enlarged scale.
In this Sheet, No. 3, the same letters as those in Sheet No. 2 have reference,
the same letters being used to indicate like parts in both sheets.
Referring to Sheet 1, Fig. 1 will be seen to be a side elevation of a roof truss
divided into two halves A and B by a central vertical line CD, each half respec-
tively forming a right-angled triangle having for its base one half of the tie-
beam F F, its altitude the line CD, and one of the rafters E for its hypotenuse.
When the pitch, or angle of inclination, of the rafters EE varies, it will be seen
that the difference will be made in the top and bottom angles, H and G, of the
rafter E, the right angle I remaining unaltered.
My said invention consists of the combination of a L shaped blade, which
represents the right angle GIH, with, and moving freely in, a stock, the said
stock representing the rafter E, can be fixed to any angle desired. It will be
seen that the angles G and H are only equal to each other when the rafter is
at an angle of. 45° with the tie-beam F and the vertical line CD. This angle
so rarely occurs in practise that it is usual to find the angles at G and H
different to each which necessitates the use of two separate bevels of ordinary
construction.
In constructing a slide-bevel according to my invention I employ a shaped
metal blade about 1" wide, and 1/16" thick, of any desired length, having its
two halves at right angles with each other as shown at 1. Fig. 1, Sheet No. 2.
The said blade being marked on one face with standard inches and parts of inches
as shown at a 1, Fig. 1, Sheet No. 2, and marked on the reverse face with feet
and parts of feet according to a scale on which one inch represents a foot as
shown at a 2, Fig. 1, Sheet No. 3. The measurements to follow each other starting
to count the first division from the angle f Fig.1, Sheets Nos. 2 and 3.
In combination with such a blade I employ a stock of any desired length, such
a stock being made of two metal halves, each half being of a channel (w)
shape, about 1/2" across the bottom and the edges turned up at right-angles for
a distance of 1/" The said halves being fastened together at the ends by rivets,
and kept apart sufficiently to allow the blade to slide between them, by the
strips of metal g. Fig. 3, Sheet No. 2. Each half of the stock has a slot or
groove cut along its length up to the separating strips at the ends, to allow
the screws of the clips to slide along it. The face edge b1, Figs. 2 and 3, Sheet
No. 2, and b 1. Fig. 2, Sheet No. 3 being marked with standard inches and parts
of inches, and the face edge 2. Figs. 2 and 3, Sheet No. 2. and 62, Fig. 2,
Sheet No. 3, being marked with feet and parts of feet according to a scale on
which one inch represents a foot, such markings to correspond with the markings
on the face of the blade next adjacent to it. An external elevation of such a
stock is shown at 6, Fig. 1, Sheets Nos. 2 and 3, a plan view in Fig. 3, Sheet
No. 2, an enlarged sectional view at Fig. 2, Sheet 2, and a portion of the face
edges of each half at Fig. 2, Sheet 3, drawn on a larger scale.
To fix and hold the blade in the stock at any desired angle, I employ two clips
of the form shown in c, Fig. 1, Sheets Nos. 2 and 3, and an enlarged sectional
view of which is shown at c, Fig. 2, Sheet No. 2. The said clips consisting of
two halves, to one of which a screw is rivetted, the screw passing through the
slots in the stock and a hole in the other half of the clip, has either a wing nut

page_text: or milled headed nut fitted on it, which by its action when tightened on the screw
draws the two halves of the stock together and holds the blade at the desired
angle.
In using my said invention the action is as follows:-
Fig. 1, Sheet No. 1, shows an elevation of a roof truss, the span or breadth of
which is twelve feet and the rise or altitude four feet. To obtain the angles G
and H of the rafter E, it is necessary to fix the face edge of the stock b 1. Fig. 3,
Sheet 2, in a line coinciding with a line drawn from a point distant 4 feet (accord-
ing to the scale on the blade) in a vertical direction from the point K of the
blade Fig. 1, Sheet 1, to a point distant 6 feet (according to the same scale) in
a horizontal direction from the point K, Fig. 1, Sheet 1.
J, Fig. 1, Sheet 1, shows the bevel set as described. The bevel being drawn
to a larger scale than the roof truss in order to show its action clearer.
Given the length of the base and the altitude of any angle for roofs or like
purposes such a bevel can be set at once very quickly and the required top and
bottom angles obtained as shown.
Where such angles are very much smaller the bevel can be set according to
the standard measurements on the reverse side of the bevel.
As this can be done in less time and with less trouble than by fixing rods or
rafters in the required positions and setting a bevel or bevels to the angles
required, the first object of my invention is attained viz. :-the construction of a
form of slide bevel which will accomplish the taking of such angles in a quicker
and easier manner than has hitherto been attained.
Again referring to Fig. 1, Sheet 1, it will be seen that, when the bevel is set
to the required angle if the face edge of the stock is held against the back of the
rafter E the two edges of the blade are respectively parallel to the top and bottom
bevelled ends of the rafter E and can be used for marking either or both of the
angles G and H. In this manner the second object of my invention is accom-
plished viz.the construction of a form of slide bevel which can be set to mark
two such angles or bevels with one setting and will obviate the necessity of using
two separate bevels to mark the two angles where the top and bottom angles
differ.
The face edge of the stock 62, Fig. 3 Sheet 2, being marked with feet and parts
of feet according to the scale on the blade, by counting the measurement between
the points where the edges of the blade cross or intersect the face edge of the
stock the length of the rafter E is obtained according to a scale on which one
inch represents a foot, thus attaining the third object of my invention viz.:-the
construction of a form of slide bevel by which the length of roof rafters and such
like oblique objects can be obtained in a simple and speedy manner.
I do not comprise in my invention a L shaped blade without any measurements
marked on it or one marked with standard inches only. Nor do I comprise in
my învention, in combination with such a blade, any other form of stock than
such a stock as is herein substantially described and shown.
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 slide bevel, the combination of a L shaped blade moving freely in a
stock whereby such a blade may he fixed and held at any required angle by the
screw-clips, such a blade and stock being marked with standard inches and parts
of inches on the one side, and with feet and parts of feet, according to a scale
of one inch to the foot, on the other side substantially as herein described and
shown with reference to the appended sheets of drawings.
2. A shaped blade which is marked on one face with standard inches and
parts of inches, and on the other face with feet and parts of feet according to a
scale on which one inch represents a foot, in combination with such a stock as

page_text: is herein substantially described and shown with reference to the appended sheets
of drawings.
3. A stock of the form shown, marked on one half of its face edge with stan-
dard inches and parts of inches, and on the other half of its face edge with. feet
and parts of feet according to a scale of one inch to the foot. The markings on
each half of the face edge of the stock to correspond with the measurements
marked on the face of the blade next adjacent to it, substantially as herein
described and shown with reference to the appended sheets of drawings.
Dated this 12th day of November 1898.
CHRISTOPHER DAVID BEVAN,
Applicant.