Improvements in Thrust Blocks for Propeller Shafts, applicable also for the Bearings of other Shafts.
Year: 1895

page_text: Date of Application. 19th Oct., 1895
Complete Specification Left, 18th July, 1896-Accepted, 29th Aug., 1896
PROVISIONAL SPECIFICATION
Improvements in Thrust Blocks for Propeller Shafts, applicable also
for the Bearings of other Shafts.
I, PERCY HADFIELD ALLSOPP, of Didsbury Road, Icaton Noiris, near
Stockport, in the County of Lancaster, Mill Manager, do hereby declare the
natue of this invention to be as follows
This invention is intended primarily for thrust blocks for the shafts of sciow
propellers, but may also be applied to footstep bearings or other beatings which
have to sustain a considerable amount of weight or pressure, and is designed to
reduce o overcome the friction.
It consists essentially in constructing the block or bearing with a cavity or
recess in the face against which the collar on the shaft bears, and maintaining the
same filled with compressed air or other fluid under picssure.
In carrying out the invention as applied to thrust bearings, I construct the
bearing of suitable size and length with the face turned and ground true at both
ends. In the face I tuin or form a cavity or recess with a small or narrow inlet.
On the shaft 1 place a suitable collar or ng tuned and ground to beat against
the face of the bearing As an alternative arrangement the cavity or recess muy
be formed in the rotating collar, but at present I prefer to form the same in the
face of the bearing.
On the top of the bearing I mount a small air pump, which is continually worked
by the rotation of the shaft. The pump is connected with the inlet to the recess
or cavity which is thus kept filled with compressed air. Instead of air, water, oil,
or other fluid may be employed. Or the pressure may be effected by connecting
the inlet of the 1ccess to the boiler.
When the shaft is working, and the weight upon the bearing, an air-tight joint
is formed, and the weight is taken off the adjacent surfaces by the pressure of the
air in the access thus relieving and reducing the fiction. The pump is worked
continuously and any excess of an passes away between the joints. Any suitable
lubricant may also be used. The same action will take place when water or oil is
employed.
if desired two ot more rings may be employed each surface being similarly
constructed.
For footstep beatings the upper surfaces of the bearing may be constructed
with a cavity for the compressed air and the end of the shaft be provided with a
collar.
Dated this 16th day of October 1895.
WM. P. THOMPSON & Co.,
6, Bauk Street, Manchester, Patent Agents.

page_text: Improvements in Thrust Blooks for Propeller Shafts, applicable also
for the Bearings of other Shafts.
I, PERCY HADFIELD ALLSOPP, of Didsbury Road, Heaton Norris, near
Stockport, the County of Lancaster, Mill Manager, 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 is intended primarily for thrust blocks for the shafts of screw
propellers, but may also be applied to footstep bearings or other bearings which
have to sustain a considerable amount of weight or pressure, and is designed to
reduce or overcome the friction.
It consists essentially in constructing a recess or cavity between the adjacent
faces of the collar on the shaft and the thrust block maintaining the same filled
with compressed an on other fluid under pressure equal to the amount of the thrust
all the time the shaft is running to reduce the friction.
It will be fully described with reference to the accompanying diawings which
show two examples applied as thrust benings.
Fig. 1 Front elevation of thrust block.
Fig. 2. Sectional elevation.
Fig. 3. Transverse section on line - Fig. 2
Fig. 4. Transverse section on line y-y Fig. 1.
Fig. 5. End elevation.
Fig. 6. Front elevation of thrust block showing a modification.
Fig. 7. Sectional elevation of same.
Fig. 8. Transveise section on line - Fig. 7.
Fig. 9 Transverse section on line y-y Fig. 6
Fig. 10 End elevation.
Fig. 11. Sectional elevation of another modification.
Fig. 12. Sectional end elevation.
The bearing or journal A is constructed of any suitable size and strength also
the colla B on the shaft C which takes the thrust. The adjacent faces of these
are tuned and ground time and in the face of one or both I foin au anuular cavity
01 recess D.
I at present prefer to form the air cavity D in the colla B the face is turned
flat and the annular cavity or recess D 18 then turned in the prepared face.
Cavities are turned in both sides of the collar B as shown where by reason of
reversing, the thrust is first exerted on one side of the collar and then on the other
The collar may however be formed with the cavity on one side only.
The thrust block is made in two parts embracing the shaft C which are held
exactly in position by means of taper pins baud set screws bor bolts. The face
of the thrust block against which the recessed face of the colln B beats is turned
flat and the adjacent faces of the collar and bluck ground together thus forming an
an tight joint.
There is a small inlet port of way d formed in the thrust bearing A through
which an is forced into the recess or cavity D in the collar B.
Instead of the recess i cavity D) being formed in the collar of the shaft it may
be formed in the face of the thrust block or it may be formed in the upper part or
cap of the thrust bearing two or more of such caps being fitted between a number
of collars placed together.
In Figs. 1 to 5 the improved thrust bearing is shown with a single collar Bon
the shaft C placed between two blocks one on eithci side and recesses made in both
faces of collar B.

page_text: In Figs. 5 to 10 I have shown the shaft formed with two collars B and the
thrust block placed between them each ring in its inner face being formed with
recess or cavity D.
In Figs. 11 and 12 I have shown the shaft C formed with a number of collars B
between each of which is placed a cap formed with the recess of cavity in
the face.
An at pump E is connected by the pipe e to the inlet d by which when the
shaft is rotating a continual supply of air is pumped into the cavity. The air
pump E is placed in any convenient position and is worked by the rotation of the
propeller shaft B by means of the eccentric F placed thereon or the an pump may
be worked independently by a small engine.
The cavity D is maintained filled with compressed air or other fluid. A little
oil may be pumped in with the air thereby helping to keep the joint an tight and
assist lubrication.
The total pressure of the an in the recess and pump is just equal to the thrust
and any excess of fluid passes away between the joint The weight is taken off the
adjacent surfaces of the collar and block by the pressure of the air thus relieving
and reducing the friction.
For footstep bearings the upper surfaces of the bearing may be constructed
with a cavity for the compressed an and the end of the shaft be provided with a
collar.
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. A thrust block for propeller or other shafts provided with a recess or cavity
between the adjacent faces of the colla on the shaft and that on the block against
which it bears such cavity being maintained filled with an elastic fluid under
pressure substantially as described.
2. A thrust bearing constructed with a cavity filled with compressed air between
the bearing or thrust surfaces substantially as descubed and shown either in Figs. 1
to 5, Figs. 6 to 10 or Figs. 11 and 12 of the drawings.
Dated this 3rd day of July 1896.
WM. P. THOMPSON & Co.,
Manchester, Liverpool, and Loudon, Patent Agents