Improvements in Screw Nuts for Split Pulley Bosses.
Year: 1897

page_text: Improvements in Screw Nuts for Split Pulley Bosses.
I, MAURICE WILLIAM SMITH, of 8 to 14, Coronet Street, Hoxton, in the County
of London, Manufacturer, do hereby declare the nature of this invention to be
as follows;-
This invention relates to screw nuts such as are used to tighten up the bosses
of split pulleys upon shafting, and has for its object to provide simple strong and
reliable nuts for the purpose.
According to my improvements I make the nut in two parts coned and screwed
internally and adapted to be fitted together face to face. From the upper inner
face or side of one part and from the lower inner face or side of the other part,
portions are cut away leaving on each side of each part a corresponding projecting
part having at and about its head a corresponding and reversed projection cut
square or angularly and in such manner that when the said formed inner faces
of the two parts are slidden together the projection of each part will fit into the
recess of the other part at each side of the nut and so form a practical solid though
bipart annular nut, the internal coned screw of which will be screwed upon the
externally screwed and coned split boss of the pulley and no movement of the two
parts of the nut in regard to one another is possible.
I prefer to make the said projecting heads of each side of each part of a nut
of angular or dovetailed form so that the nut will lock and cannot be divided
without sliding its parts in opposite directions, such nuts readily engage the
screw threads on the screw boss and are not liable to disengagement at starting
the screwing action, and no. loose pins or the like, are required. For operating
this nut, holes for a lever or a tapping lug or angular flats may be formed around
the periphery.
Improvements in Screw Nuts for Split Pulley Bosses.
I, MAURICE WILLIAM SMITH, of 8-14, Coronet Street, Hoxton, in the County
of London, Manufacturer, do hereby declare the nature of this invention, and
Price 8d.1

page_text: 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 screw nuts such as are used to unite and tighten up
the bosses of split pulleys upon shafting, and has for its object to provide simple
strong and reliable nuts for the purpose, by the use of which the pulleys can be
more readily fixed or detached than heretofore, and bolts and nuts such as are
at present in use are dispensed with. I will describe my invention with reference
to the accompanying drawings wherein Fig. 1 is a front view of the split boss
of a pulley placed upon a shaft and the two parts of my improved screw nut are
shown in position for sliding together before screwing over the boss. Fig. 2
is a similar view on the other side of the pulley showing the two parts of the screw
nut slidden and secured together and screwed over the split boss, and Fig. 3 is
a sectional plan of a pulley showing to the left the screw nut before putting
same together, and to the right the nut screwed up to working position on the
split boss.
According to my improvement I make the screw nut in two parts M and N
adapted to be slidden and fitted together face to face as hereinafter explained
and then to form an annulus which is coned and screwed internally to correspond
with the split boss B of a pulley A.
Each part M and N is as much longer than a semicircle as the length of the
parts forming the joints, and to form the joint at each side of the annulus,
portions are cut away from the inner face of one part and the outer face of the
other part. Assuming for convenience of description that the two parts are in
the position shown in Fig. 1, from the upper inner face of the part M and from
the upper outer face of the part N the portions m n are cut away to a depth
equal to about half the thickness of the metal or less, and at the outer ends of
such cut away parts are formed or left corresponding but reversed projections m² n
such as are shown in Fig. 3. A joint is formed in exactly similar manner at the
opposite side of the annulus as shown.
By this construction, when the said meeting faces of the two parts M and N
are slidden together the two projections m¹ n¹ thereon at each side of the annulus
will fit into the corresponding recesses m and n at each side of the annulus
and so form a joint of the form shown to the right of Fig. 3. Thus a practically
solid though bipart annular nut is made, the internal coned screw of which
when screwed upon the externally screwed boss B of the pulley A will efficiently
secure same to the shaft, and no movement of the two parts of the nut relative
to one another is possible.
I prefer to make the said projecting heads m¹ and n¹ at each end of each part
of a nut with angular or suitably dovetailed surfaces, such, for example, as are
illustrated at m² n² in order that the nut may lock and cannot be divided without
sliding its component parts in opposite directions; such nuts readily engage the
screw threads on the screw boss and are not liable to disengagement at starting
the screwing action, and no loose pins or the like are required. For manipulating
these screw nuts, holes such as H for a lever, or equivalently a tapping lug or
angular flats may be formed around the periphery.
Although I have described my invention particularly in reference to its use
with split pulley bosses, it is evident that it may with equal facility and efficiency
be applied to split externally screwed couplings, chucks, and so forth, without
in any way altering the features of the invention as above set forth.
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;-
Screw nuts for uniting externally screwed bosses, made in two parts coned
and screwed internally to fit upon such bosses, each said part being cut away
about each of its ends as above explained, and having projecting parts formed

page_text: in such manner that the two parts when slidden together face to face will be
securely attached and form a practically solid annular nut, substantially as herein
described and illustrated in the accompanying drawings.