Stretching Apparatus for Driving Belts or the like.
Year: 1897

page_text: Date of Application, 17th Apr., 1897
Complete Specification Left, 17th Jan., 1898-Accepted, 19th Feb., 1898
PROVISIONAL SPECIFICATION.
Stretching Apparatus for Driving Belts or the like.
I, GEORGE FREDERICK REDFERN, of the Firm of G. F. Redfern & Co., The General
Patent Office, No. 4, South Street, Finsbury, in the County of London, Patent
Agents, do hereby declare the nature of this invention (a communication to me
by Den Norske Remfabrik, of Christiania, in the Kingdom of Norway, Manufacturers,)
to be as follows:-
This invention relates to an apparatus for stretching driving belts to facilitate the
sewing together or uniting of the ends when on the pulleys.
The improved apparatus comprises two toothed bars or rails which at one end are
jointed together and at their other end have rigidly fixed a clamp or gripping device
for holding one end of the belt. This gripping device advantageously consists of a
channel shaped piece of metal having lateral flanges to which an upper clamping
plate is connected by means of screws and has two arms provided with bearings for a
shaft carrying an operating lever or handle on one end and a crank or an excentric
between the arms. To this crank is connected one end of a movable bar or rail also
provided with teeth and arranged longitudinally between the two first mentioned bars,
which latter have sliding upon them a second clamp or gripping device of similar
construction to the one previously described and adapted for holding the other end of
the belt. To this sliding clamp are pivoted pawls which engage with the three
toothed bars in such a manner that when the central bar is moved the sliding clamp
will also be moved towards the fixed clamp the pawls engaging with the fixed bars
holding the movable clamp against a return movement whilst the movable bar is
moving back preparatory to again moving the clamp forward.
The apparatus herein before described is sometimes modified in that instead of
pawls, which engage toothed rails or rack-bars, excentric cams are used, which act
frictionally on smooth rails advantageously grooved longitudinally and that instead of
the clamps or gripping devices having clamping screws and nuts, excentric grippers
are used, the gripping surfaces of the said grippers being advantageously toothed or
roughened.
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1007
Stretching Apparatus for Driving Belts or the like.
I, GEORGE FREDERICK REDFERN, of the Firm of G. F. Redfern & Co., The General
5 Patent Office, No. 4, South Street, Finsbury, in the County of London, Patent
Agents, do hereby declare the nature of this invention (a communication to me by
Price 877

page_text: Den Norske Remfabrik, of Christiania, in the Kingdom of Norway, Manufacturers,)
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:—
This invention relates to an apparatus for stretching driving belts to facilitate the
sewing together or uniting of the ends thereof when on the pulleys.
In the accompanying drawing:
--
Figure 1 is a side elevation of apparatus made according to my invention.
Figure 2 is a plan thereof,
Figure 3 is a side elevation of a slightly modified construction of apparatus, and
Figure 4 is an end elevation of the same.
The improved apparatus comprises two bars or rails a, a having teeth a' and which
at one end are jointed together and at their other end have rigidly fixed a clamp or
gripping device B for holding one end of the belt A. This gripping device B
advantageously consists of a channel-shaped piece of metal b having lateral flanges to
which an upper clamping plate o is connected by means of screws & and which has
two arms e, e provided with bearings for a shaft f carrying an operating lever or
handle g on one end and a crank or an excentric h between the arms e, e. To this
crank his connected one end of a movable bar or rail i also provided with teeth i¹
and arranged longitudinally between the two first mentioned bars a, a which latter
have sliding upon them a second clamp or gripping device C of similar construction
to the device B and adapted to hold the other end of the belt. A. To this sliding
clamp are pivoted pawis a², a², i2 which engage with the three toothed bars a, a,
and i, in such a manner that when the central bar i is moved by means of the
handle g and excentric h the sliding clamp C will also be moved towards the fixed
clamp B the pawls a², a² engaging with the fixed bars a, a holding the movable
clamp C against a return movement whilst the movable bar i is moving back
preparatory to again moving the clamp C forward.
In the modified construction of the apparatus shewn in Figures 3 and 4 instead of
the pawls engaging the toothed rails or rack-bars, excentric cams l, l, m are used,
which act frictionally on smooth rails a, a, i advantageously grooved longitudinally
to receive them as shewn in Figure 4. The said cams are mounted loosely on the
pin n, secured to the channel-shaped piece b, in such a manner that their longer
radii are remote from the two ends of the belt A so that the pull of the belt A in the
direction of the arrow Figure 3 will cause the excentrics 1, to grip the rails and
thus hold the device C in position. The forward movement of the bar i under the
action of the excentrich will cause the excentric m to grip the said bar and thus
operate the clamp C, the excentrics 1, running freely over the bars a, a.
By this arrangement the movable bar i can be moved through any distance by the
handle g and eccentric h, the said movement not being limited, as is the case with
the above described arrangement, by the length of the teeth on the bars. This is of
particular advantage when the final tension is being applied to the belt A. In this
construction, also, instead of the clamps or gripping devices B, C having clamping
screws and nuts, they are provided with eccentric grippers o, o, the gripping surfaces
of which are preferably toothed or roughened as shewn. These eccentrics are
arranged in the opposite manner to the eccentrics l, l, m, that is to say, in such a
manner that they grip the belt ends when the said ends pull in the direction of the
arrows 1 and 2 respectively of Figure 3. The said eccentrics o, o are mounted on
pivots p, p which are lodged in recesses or notches q, q formed in lugs r of the
clamps B and C and held therein by pins 8, 8.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. In stretching-apparatus for driving-belts or the like, the employment of two
clamps or gripping devices of which one is rigidly fastened to one end of two parallel
toothed bars or rails while the other is adapted to be moved along these bars or rails

page_text: by a third bar or rail, arranged between the two first bars and moved backwards and
forwards by means of an eccentric or the like, so as to intermittently, through the
medium of a pawl, move the movable clamp which is held from return movement by
pawls engaging with the fixed bars, substantially as, and for the purpose, hereinbefore
described.
2. In stretching-apparatus for driving-belts or the like of the kind described in
Claim 1, the employment of clamps or gripping devices consisting of a lower channel-
shaped part b enclosing the rails and of an upper part c the said two parts being
arranged to grip through the medium of screws, the ends of the belt, and of an
excentric h, mounted on a spindle f carrying a handle g supported in arms e, e
rigidly secured to the clamp B, the said excentric being designed to effect the
to-and-fro movement of the movable bar or rail, substantially as described and
illustrated.
3. In stretching-apparatus for driving-belts or the like of the kind described in the
preceding claiming clauses, the modification wherein, in lieu of pawls which engage
toothed racks or rails, excentric cams l, l, m are employed which engage with smooth
rails, substantially as described and illustrated.
4. In stretching-apparatus for driving belts or the like of the kind described in
the preceding claiming clauses tapering the edges of the excentric cams l, l, m and
correspondingly grooving the rails a, a, i, substantially as described and illustrated.
5. In stretching-apparatus for driving-belts or the like of the kind described in
Claims 1 and 2, the modification wherein, in lieu of the gripping pieces b and c
excentric cams o, are used which are advantageously provided with teeth or grooves
and are loosely placed in recesses or notches q in lugs r of the clamps B and C so as
to grip the belt ends, substantially as described and illustrated.
Dated the
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.