Improvements in Suspension Shackles of Weighing Machines.
Year: 1893

page_text: Date of Application, 5th Oct., 1893
Complete Specification Left, 5th July, 1894-Accepted, 11th Aug., 1894
PROVISIONAL SPECIFICATION.
Improvements in Suspension Shackles of Weighing Machines.
I, CHARLES HENRY BARTLETT of Branscombe, Woodstock Road, Bristol, in
the County of Gloucester, Scale Maker, do hereby declare the nature of this
invention to be as follows:
This invention relates to improvements in the construction of the middle and
end centre suspension shackles of weighing scales and it has for its object to
lessen the cost of manufacture and increase the strength and durability of the
shackle.
The invention consists in making the shackle (whether or not intended to receive
agate bearing blocks for the knife edge centres) of but two pieces of metal formed
and united as hereafter described.
The two faces and the one end of the shackle are formed of a single plate of
metal having an aperture stamped out of suitable form, the plate being bent or
doubled at the middle of its length to bring the faces parallel to each other at the
proper distance apart and form the upper or lower end of the shackle as the case
may be, whilst the opposite end and the sides or perimeter of the shackle are
formed of a strip of metal stamped out of proper form bent to a U-shape and
placed edgewise between the two faces to which it is secured by rivetting and by
shoulders on the strip engaging in undercut notches in the edges of the face
portions.
The aperture stamped in the plate constituting the two faces of the shackle
extends nearly from end to end of the plate and is of such form as, when the plate
is bent double and united to a perimetral plate as above mentioned, to form a
shackle of the ordinary U-form adapted to give passage to the beam and knife
edge centre.
The shackle may itself form the bearing for the knife edge or may contain
agate bearing blocks the bend at the middle of the plate being shaped
accordingly.
The rivet holes are punched out near the ends of the plate and the undercut
notches are also punched out in its outer edge at either side of the middle portion
of the plate, and the perimetral strip is punched out with laterally-extending lugs
or shoulders at its ends adapted to engage with such notches and with studs at its
middle which are rivetted over after being inserted in the corresponding holes in
the face portions.
If agate bearing blocks are provided they are secured in the shackle in the
manner described in another application for Letters Patent dated the 22nd day of
June 1893, No. 12310.
Dated this 5th day of October 1893.
C. H. BARTLETT,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in Suspension Shackles of Weighing Machines.
I CHARLES HENRY BARTLETT of Branscombe, Woodstock Road, Bristol, in
the County of Gloucester, Scale Maker, do hereby declare the nature of this
invention and in what manner the same is be performed to be particularly
described and ascertained in and by the following statement :-
This invention relates to improvements in the construction of the middle and
end centre suspension shackles of weighing scales and it has for its object to
lessen the cost of manufacture and increase the strength and durability of the
shackle.
The invention consists in making the shackle (whether or not intended to receive
agate bearing blocks for the knife edge centres) of but two pieces of metal formed
and united as hereafter described and illustrated in the accompanying drawings
forming part of this Specification, wherein
Figure 1 is a longitudinal elevation of part of the beam, the middle and one end
shackle together with the corresponding knife edges being in central vertical
section.
Figure 2 is a plan.
Figure 3 is a transverse section through the middle centre suspension shackle.
Figure 4 is a transverse section through the end centre suspension shackle.
Figures 5 and 6 show developed in the flat the two parts of which the middle
shackle is made.
Figures 7 and 8 are similar views of the parts of which the end shackle is
composed.
Figure 9 is a perspective view of the middle shackle.
In all the above figures the shackles are not provided with agate bearing blocks
but such bearing blocks may be provided and fixed as hereafter explained.
The two shackles are similarly constructed and their parts are denoted by
the same reference letters, each shackle being composed of but two pieces of
sheet metal A and B stamped out of the forms shown in Figures 5 6, 7 and 8
that is to say the two faces a a and the one end a¹ of the shackle are formed
of a single plate of metal A having an aperture e stamped out of the form
shown in Figure 6. To form the shackle the plate is bent or doubled at the
middle of its length to form the V-shaped bearings a' for the ends of the knife
edge centre and to bring the faces a a parallel to each other at the proper
distance apart, the V-shaped bearing for the knife edge centre being at the
upper or the lower end of the shackle according as the shackle is to be used
at the end or the middle of the beam. The opposite end and the sides of the
perimeter of the shackle are formed of a strip of metal B stamped out of the
form shown in Figures 5 and 7 and bent to a U-shape and placed edgewise
between the two faces a a to which it is secured by the shoulders of the
enlarged ends of the strip engaging in undercut notches d in the edges of the
face portions a and by studs on the strip B being rivetted into apertures d'
in the face portions a the parts A and B being thus firmly united.
The aperture e stamped in the plate A extends nearly from end to end of the
said plate is of such width as to admit the beam and is provided with lateral
recesses to give passage to the knife edge centre of the beam.
It will be understood that in fitting together the parts A and B the ends of the
one come opposite the middle bend of the other and vice versa. The middle centre
shackle has a rigid suspension eye D, rivetted to its upper end for the suspension
of the scales from a support above, whilst the end centre shackles have each a
swivel eye E pivoted to its lower end for the attachment of the scale pan suspension
chains.
F is the scale beam, G is the middle knife edge centre and H is one of the end

page_text: knife edge centres. Each of these knife edges is secured to the beam in the
manner described in the Specification of a previous Patent granted to me dated
June 22nd 1893 No. 12310 that is to say the knife edge is seated in a V-shaped
notch cut in the edge of the beam and is secured therein by a U-shaped strap I
having eyes i which embrace and bear against the back of the knife edge bars, the
strap being provided with a pressure screw J bearing against the edge of the
beam F and screwing through a hole tapped in the bend of the strap I.
The shackle instead of being adapted to itself form the bearing for the knife
edge as at a' may contain agate bearing blocks, in which case the bends at a¹ would
be made rectangular and the agate bearing blocks would be secured in the shackle
in the manner described in my previous Patent aforesaid.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The construction of the suspension shackles of the weighing scale of two
plates of metal punched out and bent to U-shape fitted together, the middle bend
of the one opposite the ends of the other, and united to form a shackle substantially
as specified.
2. In the construction of the suspension shackles of weighing scales of two
plates, as described, the interlocking of shoulders on the ends of the plate forming
the perimeter or edge of the shackle with undercut notches made in the edges of
the plate forming the faces of the shackle, as described.
3. In the construction of the suspension shackles of weighing scales of two
plates, as described, the interlocking of shoulders on the ends of the plate forming
the perimeter or edge of the shackle with undercut notches made in the edges of
the plate forming the faces of the shackle, in combination with studs on the
edge of the former plate rivetted into holes made in the latter plate, as
specified.
Dated this 5th day of Jul 1894
C. H. BARTLETT,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.