Year: 1898

page_text: Date of Application, 13th Apr., 1898-Accepted, 9th July, 1898 -
A communication from DANIEL MYERS, 69, Clinton Street, Cleveland, Cuyahoga
County, State of Ohio, United States of America, Wholesale Druggist.
I, ALFRED JULIUS BOULT, of 111, Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, 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 invention relates to certain improvements in scales, and particularly to
so-called platform scales; although certain parts of the invention may be used
in connection with the bearings for .scale beams. In platform scales, as com-
monly constructed, the platform is supported at the four corners on knife edge
bearings which are arranged in pairs as nearly in alignment as practical. These
knife edge bearings engage with hardened bearing blocks carried by the plat-
form. Usually one pair of said bearing blocks have V-shaped notches which
embrace one pair of knife edges, whereby movement of the platform transverse
to said knife edges is prevented. The scale beams also carry two aligned knife
edges which are supported in V-shaped notches in co-operative hardened bear-
ing blocks, which are supported on a fixed scale member, that is, on a part of
the scale framework.
In an accurate ard sensitive scale, each of these knife edges and the co-operat-
ing V-shaped notches in the associated bearing blocks, must be in perfect align-
ment relative to each other; and the knife edge bearings and the blocks must
engage squarely with each other, to prevent binding and to diminish friction
when the scale is operated,-which results are very difficult to attain unless the
bearing blocks are adjustable. The present invention has for one of its objects
to make these bearing blocks automatically adjustable, so that they may engage
properly with the knife edges, the construction of the parts being such that
the automatic adjusting movements shall be effected with no appreciable friction.
Another purpose of the invention is to so connect the adjustable bearing blocks
with the parts which carry them, that said parts may be taken out of the scale
and handled, without danger that the bearing blocks will be lost or get out of
proper operative position. In counter scales, which are among the scales to
which the present invention is applicable, it is often necessary to remove the
platform for the purpose of cleaning the same. One object of the present inven-
tion is to provide means whereby even an unskilled person shall invariably, in
returning the platform to the scale, cause it to engage properly with the sup
porting knife edge bearings. In many scales of the general character referred
to, the platform is composed of two parts viz., a part commonly called the sub-
platform, which rests upon and is supported by the knife edge bearings before
referred to, and the plate or upper platform, which rests upon the sub-platform.
One part of the present invention relates to the means for maintaining the upper
platform and sub-platform in proper relation to each other.

page_text: In the drawings Figure 1 is a front elevation of a scale embodying the inven-
tion; Figure 2 is a plan view of the base, when the upper platform is removed,―
this view showing the platform levers and the 'sub-platform resting thereon;
Figure 3 is a vertical sectional view in the plane indicated by line 3-3 of
Figure 2; Figures 4 and 5 are, respectively, a perspective view of one of the
bearing blocks G, and a perspective view of one of the plates H; Figure 6 is a
sectional view of a substitute construction; Figure 7 is an enlarged sectional
view of one of the bearing blocks G, associated plate H, and the interposed balls;
Figure 8 is a sectional plan view of the upper part of the scale on line 8-8 of
Figure 1; Figure 9 is a sectional view on line 9-9 of Figure 8; Figure 10 is
a vertical sectional view corresponding to that shown in Figure 3, but showing
(1) a modified construction of the means for holding the self-adjusting bearing
blocks in proper position, and (2) novel means for supporting the upper plat-
form upon the sub-platform; Figure 11 is a bottom view of one of the legs of the
sub-platform shown in Figure 10.
The scale shown in the drawing is a so-called computing scale, and it is, except
in respect to those parts thereof which constitute the present invention, substan-
tially like the computing scale shown and described in British Patent 822 of
1897. This particular scale, however, is shown siniply because the invention
has been successfully used in connection with such a scale; but the invention is
applicable to any form of beam scales or platform scales,-whether they are
computing scales or merely scales intended to indicate weight. But. neither the
particular arrangement of beams, nor their graduation, to which features the
computing qualities of the scale are due, are material to this invention.
Referring to the parts by letters, W represents a hollow scale base which
encloses and supports the platform levers A and C, which may be of any approved
form. The lever A carries two horizontal knife edge bearings a a,
which are
arranged as nearly as may be in the same horizontal plane and in alignment,
near the front of the scale. The lever C carries two similarly. arranged knife
edge bearings c c near the rear of the scale. In some scales the upper platform
rests upon the sub-platform which is supported upon the knife edges. This con-
struction is shown in the drawing; but the invention is equally applicable to
a scale wherein the platform is made in one piece; in fact, it may be assumed,
for the purpose of this description, that the upper platform E, as shown in
Figure 3, is rigidly fastened to, or is a part of, the sub-platform E. In the
remainder of this description, the part which carries the bearing blocks will
be referred to as the platform, while the removable top plate will be .called the
upper platform.
At each of the four corners of the platform is a downwardly extended leg, e.
Each leg is bifurcated, the furcation e¹ extending in the same direction as the
corresponding knife edge bearings a or c. Each bifurcated leg forms an effective
housing for a self-adjusting bearing block, which housing has two vertical
sides e²e and a horizontal end. The end is a hardened surface which is, in the
best construction, formed by a plate H which is rigidly fastened therein. The
end plate, so-called, may, however, be an integral part of the housing.
G represents a bearing block, one of which bearing blocks is placed loosely
in each of said housings; and it is free to move, to the extent hereinafter indi-
cated, in various directions, that is to say, it is able to move slightly in all
directions in a substantially horizontal plane, and its ends are also movable
up and down about a fulcrum furnished by the balls J. In the proximate sur-
faces of each plate H and bearing block G are formed depressions h¹ g¹-the
bottoms of which are preferably slightly concave. As shown in Figures 4 and 5,
two. depressions are formed in each plate and block, and the depressions are
arranged substantially as shown in Figures 3 and 7, whereby a vertical plane
passing through the center of both balls will be transverse to the housing and
at right angles substantially to the corresponding knife edge. Between each

page_text: plate H and block G, and in the depressions referred to, are placed two hard
metal (preferably steel) balls J J, which, because they are in said depressions,
form a single row transverse to the housing. The depressions are of such size
that the balls may move in them to a limited extent, that is to say, until the
balls engage with the sides of said depressions,--wherefore it is evident that the
bearing blocks G may move more or less relatively to the plates H, both horizon-
tally in all directions, and as upon a horizontal axis coincident with the line
of contact between the balls and block G.. In the outer. (lower) surface of the
two front blocks G are the V-shaped grooves which are intended to bear evenly
upon the knife edges a. The movements of the block G upon the balls as
described, allow said blocks to automatically fit themselves upon said knife
edges, and that obviously with practically no friction. The lower faces of the
rear bearing blocks G.may have plane horizontal surfaces, wherefore the
described horizontal movement of the blocks is unnecessary; but the blocks
will rock upon the balls, as previously described and thereby automatically come
into a position resting squarely on the knife edge bearing c.
It is believed that the particular construction of the bearing blocks G and
plates H shown in Figures 4 and 5, and heretofore described, is, for many reasons,
the best; but a modified construction is shown in Figure 6. In the construction
shown in Figure 6, the block G is provided with two studs g³ g³-said studs
being arranged transversely with respect to the V-shaped groove. The plate H
has two very deep depressions . The balls rest upon the studs, and, not only
the balls, but the studs also enter the depressions so far that the ends of the studs
will, when the blocks move, engage with the sides of the depressions, thus
limiting the relative horizontal movement of block and plate.
In a practical construction, these blocks should be prevented from moving so
far away from the plates H as to permit the balls to escape from said depressions
when the part which carries the blocks (for example, the platform as shown in
most of the figures) is lifted off the platform levers. To secure this result, two
pins e, which are secured to the sides of the housing, loosely enter holes g³ in
the sides of the associated block G. These pins are not pivots, nor do they sup-
port any of the weight of the parts when said parts are assembled as described;
their only function being to prevent the blocks G from moving out of operative
position with respect to the plates H and interposed balls J-in other words,
to prevent the blocks from moving far enough away from the plates H to permit
the escape of the balls J from the depressions referred to.
In Figure 10 other means are shown which act substantially as do the pins
referred to, to prevent the described objectionable movement of the blocks G.
These means consist of the plates K which are secured to the bottom of each
side of the housing. The inner ends of these plates project under the edges of
the blocks G, wherefore they prevent the blocks from falling out of the housing,
and, because they are close to said blocks, they prevent them from moving far
enough downward to permit the balls to escape from the depressions. The inner
ends of these plates are bevelled, as shown, so as to guide the knife edges a or c
into engagement with the blocks when the parts are being assembled.
The invention, considered broadly, is not limited in its use to the scale platform,
but may be used at any other point in the scale, when such use would be advan-
tageous; for example, the bearings for the scale beams may be similarly con-
structed. In Figures 8 and 9 the particular form of the bearing which is best
for the purpose, is shown. Two fixed brackets b b are bifurcated (Fig. 9), thereby
forming a housing like those formed by bifurcating the legs of the platform. A
plate His rigidly secured in a horizontal position so as to form the bottom of said
housing. One of the bearing blocks G' is loosely fitted in each housing above the
plate H. In the upper surface of said block V-shaped grooves are formed;
and the aligned knife edge bearings d, which are secured to and project horizon-
tally in opposite directions from the beam D rest upon said bearing blocks and in

page_text: said V-shaped grooves.
In the bottom of the block G¹, and in the top of the
plate H the depressions g¹ h¹ are formed, and two balls J J lie in said depres-
sions, the blocks resting thereon. The depressions are so placed that a vertical
plane passing through the center of both balls is at substantially right angles
to the knife edge bearings d. A plate b is secured to the top of the sides of
the housing, which plate lies so close to, but out of contact with the knife edge
bearings dd, that only a very limited upward movement of said bearing could
take place, this movement being so small that the bearing block could not
move away from the plate H¹ far enough to permit the balls to escape from said
depressions. The blocks G¹ have the same freedom of motion as do the blocks G
in the platform legs, because they are constructed and mounted in a similar
manner, and they automatically adjust themselves so as to properly engage with
the knife edge bearings d.
•
Although, as before stated, the platform may be made in one piece, it is desir-
able to construct it in two parts, and to support the upper platform upon the
platform which carries the bearing blocks G.
It is also desirable to provide means for levelling the platform, and for main-
taining said platforms in substantially the same relation to each other, while
permitting a slight but substantially frictionless horizontal vibration of the upper
platform. These results are produced by the following means; At the corners
of the platform, above the bearing blocks, are the vertically adjustable ball
cups M. These ball cups are concave depressions in the tops of the heads of
screws or bolts m, which are carried by the platform and are vertically adjustable
with respect thereto. These screws screw down into the platform, their lower
ends entering lateral recesses e. Each of these is open from one side, whereby
a wrench may be introduced to operate the jam nut m' on the lower end of the
screw. On the inner side of the upper platform El are similarly arranged ball
cups c
A ball N is placed between each pair of cups, that is to say, it rests
in the cup M, while the cup e rests upon the ball. By adjusting one or two or
three of the cups M up or down, the platform may be levelled and caused to
bear evenly on all of the balls N. At the same time the platfrom E' may move
slightly in all directions and that without much friction, and without transmit-
ting any considerable strain to the knife edges a a cc. The upper platform E¹,
however, automatically returns to its normal position relative to the platform E.
Having now particularly described and ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondent, and in what manner
the same is to be performed, I declare that what I claim is :-
1. In a scale, the combination of a scale member having two or more housings,
each of which consists of two sides and a horizontal end, a bearing block loosely
fitted in each housing, the end of each housing and the adjacent horizontal
face of the associated bearing block having each a single row of correlated depres-
sions, a single row of balls confined between the block and housing and in said
depressions, whereby said block may move horizontally and may rock as upon
an axis coincident with the line of contact between the balls and block, and
means which prevent the block from moving far enough from the end of the
housing and to permit the escape of the balls from said depressions, substantially
as specified.
2. In a scale, the combination of a platform having downwardly projecting
supporting legs which are vertically bifurcated to form housings, each housing
having two vertical sides and a horizontal end, hardened bearing blocks loosely
fitted in each housing, the horizontal end of the housing and the proximate face
of the corresponding bearing block having a transverse row of depressions, a row
of balls in said depressions upon which the bearing block may rock as upon a
pivot, pins secured to the sides of the housing and projecting loosely into holes
in the sides of the block, whereby said pins serve not as pivots for the blocks,

page_text: but merely to retain the blocks in the housings and to limit their movement,
substantially as specified.
3. In a scale, the combination of two fixed supports which are bifurcated to
form housings composed of two sides and a horizontal end, an independent bear-
ing block loosely fitted in each of said housings, the proximate horizontal sur-
faces of each block and its housing end having transverse depressions, and a row
of balls confined in said depressions between each block and its housing end,
with a scale beam having projecting from opposite sides two aligned knife edge
bearings which rest upon said blocks, and cap plates secured-to-the-sides-of-the-
housings above said knife edge bearings, substantially as specified.
4. In a scale, the combination of a platform having bifurcated legs, which serve
as housings, bearing blocks loosely fitted in said housings, a row of balls inter-
posed between each block and the end of the housing and confined in depressions
in said blocks and housing ends, and plates having bevelled ends secured to the
ends of the legs and extended under the edges of the bearing blocks, with plat-
form levers and knife edges carried by said levers and adapted to support said
bearing blocks, substantially as specified.
5. In a scale, the combination of a platform having a plurality of vertically
adjustable ball cups secured thereto, an upper platform having corresponding
ball cups on its lower face, and balls, which are interposed one between each
pair of ball cups, substantially as specified.
Dated this 13th day of April 1898.
BOULT & WADE,
Agents for the Applicant.