Improvements in or relating to Screw Tipping Gear. for Wagons and Carts.
Year: 1895

page_text: Date of Application, 31st Dec., 1895
Complete Specification Left, 21st Sept.. 1896-Accepted, 14th Nov., 1895:
PROVISIONAL SPECIFICATION.
Improvements in or relating to Screw Tipping Gear. for Wagons
and Carts.
We, THE BRISTOL WAGON AND CARRIAGE WORKS COMPANY LIMITED Of
Lawrence Hill, Bristol, Wagon and Carriage Builders and JAMES MACDONALD of the
same place Engineer, do hereby declare the nature of this invention to be as
follows:
This invention has reference to screw tipping gear for wagons and carts of the kind
in which the front of the wagon or carriage body is tipped by means of a vertical
screw which works through a nut on the under side of the body, the lower portion
of the screw passing through a boss and being rotated by mitre gearing by means
of a handle.
In this screw tipping gear as hitherto constructed a shoulder or flange in the
vertical screw rests upon the boss which thus forms the bearing of and takes the
friction of the screw. This friction is considerable and it is the object of this invention
to reduce it.
With this object we form one or more annular grooves in the upper face of
the said boss and one or more corresponding grooves in the lower face of the shoulder
or flange of the vertical screw and in these grooves we place a series of balls.
The friction and weight of the screw are thus borne by the balls and as these move
during the rotation of the screw the friction is greatly reduced.
Dated this 31st day of December 1895
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents.
Improvements in or relating to Screw Tipping Gear for Wagons
and Carts.
WO, THE BRISTOL WAGON AND CARRIAGE WORKS COMPANY LIMITED of Lawrence
Hill, Bristol, Wagon and Carriage Builders and JAMES MACDONALD of the same
place, Engineer, 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 :-
This invention has reference to screw tipping gear for wagons and carts of the kind
in which the front of the wagon or carriage body is tipped by means of a vertical
screw which works through a nut on the under side of the body, the lower portion
of the screw passing through a boss and being rotated by mitre gearing by means of
a handle.
In this screw tipping gear as hitherto constructed a shoulder or flange in the
vertical screw rests upon the boss which thus forms the bearing of and takes the
friction of the screw. This friction is considerable and it is the object of this invention
to reduce it.
With this object we form one or more annular grooves in the upper face of the

page_text: said boss and one or more corresponding grooves in the lower face of the shoulder
or flange of the vertical screw and in these grooves we place a series of balls. The
friction and weight of the screw are thus borne by the balls and as these move
during the rotation of the screw the friction is greatly reduced.
This invention is illustrated by the accompanying drawings, in which
Figure 1 is a sectional elevation of an arrangement of screw tipping gear pro-
vided with our improvements and Figure 2 is a general elevation of a four
wheeled wagon illustrating the application thereto and mode of operation of our
improved screw tipping gear.
In these figures, 1 is the vertical screw by means of which the wagon body A
is tipped. This screw is adapted to adjust itself to the arc in which the front of
the wagon body moves when tipped. For this purpose the lower portion 1" of the
screw passes through a boss 2 formed on a horizontal spindle 3 which works in
bearings 4 (only one of which is shown) attached to the under frame of the wagon.
The screw-threaded portion 1 of the screw works in a nut (not shown) mounted
by means of trunnions capable of movement in elongated holes in brackets fixed to
the wagon body. As the wagon body is being tipped, the nut and the spindle 3
turn on their axes to allow the screw 1 to accommodate itself to the arc in which
the front of the wagon body moves. The screw is rotated by means of a pair of
bevel wheels 5 and 6, one bevel wheel 5 being fixed on the end 1ª of the screw,
and the other bevel wheel 6 being fixed on a horizontal spindle 7 which abuts against
a lateral cylindrical extension 2a formed on the boss 2. This extension 2ª acts as
a guide for the bevel wheel 6 and the spindle 7 to ensure their proper position in
line with the spindle 3. The spindle 7 is carried in bearings 8 (only one of which
is shown) fixed on the under frame of the wagon. The requisite rotary motion for
effecting the desired tipping movement is imparted to the spindle 7 by means of a
crank handle 9.
With the object of reducing the friction resulting from the load on the screw at
the place of contact between the vertical screw 1 and the supporting boss 2, an
annular groove 10 is formed in the lower face of the shoulders 11 of the screw 1,
and a corresponding annular groove 12 is formed in the upper face 13 of the boss 2
and in these grooves 10 and 12 are placed a ring of loose balls 14 which support the
load and convert the otherwise rubbing or grinding friction of the load carrying
contact surfaces into the very much smaller rolling friction.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :---
1. In and for tip-wagons, carts and the like the combination with screw tipping
gear of ball bearings to the screw, substantially as and for the purposes described.
2. The combination and arrangement of parts forming the improved screw tipping
gear substantially as described and as illustrated in Figure 2.
Dated this 21st day of September 1896.
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents.