Improvements in or relating to Apparatus for Stopping and Braking the Motion of Machines, Power Shafts, Engines, Gearing, and the like, in the Case of Danger or Accident, so as to Prevent Injury, and in Devices to be Used in Combination therewith or Separately.
Year: 1888

page_text: Date of Application, 30th Jan., 1888
Complete Specification Left. 30th Oct., 1888
Complete Specification Accepted, 8th Jan.. 1899
Improvements in or relating to Apparatus for Stopping and Braking
the Motion of Machines, Power Shafts, Engines, Gearing, and
the like, in the Case of Danger or Accident, so as to Prevent
Injury, and in Devices to be Used in Combination therewith or
Separately.
Germany, Manufacturer.
I, WILLIAM PHILLIPS THOMPSON F.(.S. M.I.M.E. of the Agency for Foreign
Patent Solicitors 6, Lord Street Liverpool and 6, Bank Street, Manchester, both in
the County of Lancaster, and 323 High Holborn in the County of Middlesex, Civil
Engineer, do hereby declare the nature of this invention to be as follows:-
:-
The present invention relates to protecting devices, which can be applied to shafting,
machine tools, and motors, averts the danger of being caught by a shaft, belt, fly
wheel or pulley, in such a manner that if a person is scized by a moving piece of
mechanism, et cetera, such as the above, and carried away by it, the movable protecting
device causes either the driving belt to be thrown off, and a braking power applied, or
the stopping of the supply of motive power to the engine, and a brake to be applied
to the fly wheel at the same time.
Those parts of the mechanism which may directly or indirectly be dangerous for
the workinen, are surrounded by a movable protecting fencing which under ordinary
and regular conditions remains at rest, but is set automatically in motion in the case
of iminent danger by the person who is exposed to the danger, and causes thereby,
the stoppage of the whole of the machinery, or a part of the same in such a short time
that no serious consequence can ensue to the person concerned.
The invention is best described by aid of the accompanying drawings, in which:
Figures 1, 2, and 3, which are respectively side elevation, end elevation, and plan,
show a line of shafting provided with the protective device.
Figure 2 is a side view of the brake, and the apparatus for throwing off the
main belt.

page_text: Figures 4 and 5 the invention illustrated diagrammatically as applied to a
rolling mill.
.
Figure 6 illustrates in the same way the means employed for shutting steam off an
engine by means of the protecting device.
Figure 7 a means of transmitting direct, the motion of the safety hoop to the
cord F.
Figures 8 to 11 details of the protecting device.
Close to the pulley A (Figures 1, 3, 8, and 9) are the clamps a provided with an
inner lining of leather soaked in glycerine and arranged on the shaft B in such a
manner that the latter can freely revolve when the clamps a are held firmly in
position. A joint piece (Figure 9") is introduced and firmly beld between the
Hanges of these clamps by means of one of the flange bolts; a jaw c (figure 9) is
fixed on the round shank of the joint b.
The clamps a thus fitted, are applied on both sides of the pulleys. If one side of
the pulley is close to a bracket or hanger, the clamps are applied on the end or free
side of the bracket, or on to the shaft. The jaws c of two clamps forming the ends
of a free length of shaft, are opposite each other, and can be connected together by
means of a connecting rod C.
The jaws of these clamps are preferably placed in such a position that the connecting
rods lie immediately in front of the shaft and accordingly prevent a close contact
with the front part thereof. This position of the rods is not an essential one, but they
must of course always occupy such a position that the person caught by the shafting
comes immediately in contact with the rod (!.
The shank carries a piece d (Figures 8 and 9) in which the hoop D which
surrounds the pulley A, is fitted or fixed. A cord loaded by the weight E (Figures 2,
8, and 10) is attached to the hoop D, and passes over a pulley K by means of which
the weight of hoop D, rod C, and other parts belonging thereto, is balanced.
a
A tight rod F runs along the ceiling parallel to the shafting B. It passes over
rollers, and is at one end fixed to a lever H (Figures 1 and 8) for throwing off the
driving belt, and at the other end provided with a cord tightening device. The latter
is formed by passing the extremity of the cord over an end pulley and through
fixed eye g (Figure 1) and attaching to its end a weight. All the counterweights E
are connected by cords h, (Figures 1, 2, 8, and 9) with the tight cord F, which is,
however, not affected during the regular working, as the weights are counterbalanced
by the weight of the protecting device.
Now if an object be caught and carried away by the shaft B, the belt or the
pulley A, it must come in contact with the connecting rod C, or with the hoop D, and
shift these parts upwards. As soon as this takes place, the end of the cord i to which
the weight is attached, is lowered, and the weight pulls the tight cord F. The
weight G is therefore raised until it touches the eye g, when it cannot rise further, and
the weight E therefore pulls the lever H, and thereby brings the throwing off gear of
the main driving belt into action, and at the same time, causes a breaking device to
act on the main driving pulley. This throwing off gear can be actuated by mechanical,
electric, hydraulic or pneumatic power, but its action must be as quick as possible, so
that the person seized by the shaft, etcetera, shall not be seriously injured before the
motion is stopped.
In the case under consideration, the throwing off gear is set in action by mechanical
means. The lever H connected to the tight cord F (Figures 1, 2, 5 and 11) is
provided with a projection (Figure 8) bearing against a claw on the pulley I,
connected with another pulley K. Round the pulley I (figures 2ª and 8) a cord m
passes, one end being attached thereto, and the other end carrying the disconnecting
weight M (Figure 2) kept at rest by the claw held by the projection of the lever H.
A second cord n' round the pulley K carries the weight n, by means of which the
claw is brought back when desired, against the projection K of the lever H.
The weight M is connected with the belt fork shifter N by a cord o passing over a
pulley O. The other end of N is likewise connected with a loaded cord for the
purpose of bringing the said belt shifter back to its former position, and thereby allow

page_text: the driving belt to be shifted onto the fast pulley again. The hand lever L pulls by
means of a hook (Figure 1) the brake lever P, and its brake block Qaway from the
fast pulley R¹.
The mode of action is as follows :-
The projection of the lever H holds firmly as mentioned the claw of the pulley I,
and the brake apparatus is thereby at rest. If at the moment of danger the cord F
be pulled in the manner above described, the lever H is drawn back, and the claw / is
disengaged. The weight G falls at once, and by means of the cord o and belt shifter N
the driving belt is shifted to the loose pulley R, the hand lever L is pulled down at the
same time, and releases the brake lever P, which through the action of the weight X
applies the brake block Q against the fast pulley R¹.
It is advantageous to give a wedge shape to the brake block, and to arrange it so
that the fast pulley itself applies the brake.
By properly calculating the weights M and X, and giving the proper position to
the brake block Q, the fast pulley R, and with it the whole line of shafting, can be
brought to a standstill almost immediately, so that the person in danger has time to
free himself.
When this has occurred, the lever L is lifted by its handle, and the weight M
thereby raised. The counterweight of the belt fork shifter N moves it the necessary
distance to bring the belt back to the fast pulley. The brake lover P and the brako
block sink down in consequence of their own weight, and the weight n turns the
pulleys K and I until the claw engages the projection of the lever H which a spring
has brought back into its position of rest.
If now the hand lever is set free, the projection of the bar H receives again the
pressure of the weight M, and the throwing off gear cannot come into action.
If electricity is to be used to actuate this or any protecting device, the motion of
the lever H can be utilised to close a circuit, or instead of the tight cord F a conducting
wire may be used with advantage, and the arms of the protecting hoop D made long
enough to permit them to come to rest on the wire, or again a special rod may be
introduced between the back flanges of the clamps a, which rod is bent to such a shape
so as to form contact with the conducting wire.
In applying this modification, the protecting device can be counterbalanced by
means of weights in the manner already described, or there can be counterweights on
the arms of the protecting hoops, or the counterweights may be arranged on rods
inserted between the flanges of the clamps a.
If now the protecting device is raised, the arms of the same, or the rod adapted to
the clamps a touch the tight wire, thereby closing the circuit, and the electric current
effects the throwing off of the driving gear.
As the protecting hoop, set in motion, will, after coming in contact with the con-
ducting wire, probably move a little further before it stops, the protecting device
would break, if it is prevented from accomplishing this small further motion. In the
application of the aforementioned conducting wire, this draw-back is not to be feared,
because the wire is depressed by the end of the hoop in contact with it, or by the rod
attached in the clamp a, and it afterwards resumes it former position owing to its
elasticity.
If, on the contrary, the tight cord F is depressed by one of the rods forming the
prolongation of the hoop D before the throw off gear comes into action, the rod must
extend beyond the cord F sufficiently to prevent it slipping off the same. The end of
this rod can be jointed so that the cord F can return automatically to its proper position
as soon as the hoop D has resumed its normal position. This arrangement which
would correspond almost entirely to that described with respect to the use of electricity,
is represented in perspective on Figure 7.
On the side opposite the hoop D there is introduced in the clamps a, a rod D'
similar to the piece of Figure 9. This rod D¹ is weighted in such a manner as to
balance the weight of the hoop B, which consequently keeps the position assigned to
it. The rod D extends a little beyond the tight cord F, but can also rest lightly on
it. (When electricity is applied and a conducting wire used instead, such a contact is

page_text: a
of course not allowable). This end of the rod D¹ is, as shown on Figure 7, jointed;
small spring prevents the motion of the joint, so that when the hoop is moving upwards
the end of the rod is stiff, and the cord is depressed. The further rotation of the
hoop D overcomes the feeble pressure of the small spring, and causes the joint to be
beni, and the rod D³ passes the cord F. The jointed device of the rod D is not repre-
sented on the drawing, because such a device is generally known and easily understood
without any further description.
The tightening of the cord F can be utilised in conjunction with the device shown
in Figures 8, 10, and 7 to make a contact or complete a circuit. When water, air
pressure or explosive mixtures are employed to actuate the throw off gear, the motion
of the tight cord F or lever H can effect the opening of a water or air valve.
These devices are very suitable for workshops etcetera, where there are several lines of
shafting, and for which there must be the same number of lines of cord or wire. Pro-
tecting devices can also be easily applied to machine tools in connection with which
workmen are easily wounded.
In a rolling mill, such as that shown diagrammatically on Figures 4 and 5, the
clamps a are fixed on the axles of the rollers, and the rod is so situated that only a
body of the thickness of the plate to be rolled can pass through; any other thicker
body comes in collision with the rods C, thereby moving them, and bringing into
action the throwing off gear in the manner already described.
Similar to the foregoing are the protecting devices for toothed wheels, saw blades,
etcetera. It is therefore superfluous to go into any further description respecting
them.
In cases where the driving belts cannot be shifted on a loose pulley, such as for
instance, the belts that derive their motion directly from the engine, it is advantageous
to close the admission or regulator valve, and to effect the braking of the fly wheel by
means of the protecting device. Figure 6 shows such an example.
The movable protection hoop C surrounds the fly wheel, and is balanced aud hung
to a cord passing over rollers fixed in the ceiling, the other end of this cord being
wound round a disc several times fixed on the valve spindle.
If the engine attendant moving the fly wheel to start the engine is caught by
it, he at once comes in contact with the hoop C, which then follows the motion
of the fly wheel shaft, and the regulator or valve spindle is put in motion. If the
periphery of the cord disc on the valve is in the proper proportion to the periphery
of the fly wheel, the steam is shut off (for example, when the dotted position Chas
been attained) and before the workman has been hurt.
The braking apparatus is not shown in this Figure.
It could for example be
brought into action by the striking of the hoop C against a throw off gear.
Dated this 28th day of January 1888.
WM. P. THOMPSON & Co.,
Agents for the Applicant.

page_text: Improvements in or relating to Apparatus for Stopping and Braking
the Motion of Machines, Power Shafts, Engines, Gearing, and
the like, in the Case of Danger or Accident, so as to Prevent
Injury, and in Devices to be Used in Combination therewith or
Separately.
1, WILLIAM PHILLIPS THOMPSON F.C.S. M.L.M.E. of the Agency for Foreign
Patent Solicitors 6, Lord Street Liverpool and 6 Bank Street, Manchester, both in
the County of Lancaster & 323 High Holborn in the County of Middlesex Civil
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 :-
The present invention relates to protecting devices which can be applied to shafting,
machine tools and motors and which avert the dangers of being caught by a shaft,
belt, fly wheel or pulley, in such a manner that if a person is seized by a moving
piece of mechanism etcetera such as the above and carried away by it, the moveable
protecting device causes either the driving belt to be thrown off and a braking
power applied, or the stopping of the supply of motive power to the engine and a
brake to be applied to the fly wheel at the same time.
Those parts of the mechanism which may directly or indirectly be dangerous for the
workmen, are surrounded by a moveable protecting fencing which under ordinary
and regular conditions remains at rest, but is set automatically in motion in the case
of imminent danger by the person who is exposed to the danger and causes thereby
the stoppage of the whole of the machinery or a part of the same in such a short time
that no serious consequences can ensue to the person concerned.
The invention is best described by aid of the drawings accompanying the Provisional
Specification, in which Figures 1, 2, and 3, are respectively a side elevation, end
elevation, and plan, showing a line of shafting provided with the protective device.
Figure 2a side view of the brake and the apparatus for throwing off the main
belt.
Figures 4 and 5, the invention illustrated diagrammatically as applied to a rolling
mill. Figure 6 illustrates in the same way the means employed for shutting steam
off an engine by means of the protecting device. Figure 7 a means of transmitting
direct the motion of the safety hoop to the cord F, figures 8 to 11 details of the
protecting device.
Close to the pulley A (figures 1, 3, 8 and 9) are the clamps a provided with an
inner lining of leather soaked in glycerine and arranged on the shaft B in such a
manner that the latter can freely revolve when the clamps a are held firmly in

page_text: position. A joint piece 6 (figure 9") is introduced and firmly held between the flanges
of these clamps by means of one of the flange bolts, a jaw c (figure 9) is fixed on the
round shank of the joint b.
The clamps a thus fitted are applied on both sides of the pulleys. If one side of
the pulley is close to a bracket or hanger, the clamps are applied on the end or free
side of the bracket or on to the shaft. The jaws c of two clamps forming the ends of
a free length of shaft, are opposite each other and can be connected together by
means of a connecting rod C.
The jaws of these clamps are preferably placed in such a position that the connecting
rods C lie immediately in front of the shaft, and accordingly prevent a close contact
with the front part thereof. This position of the rods is not an essential
one, but they
must of course always occupy such a position that the person caught by the shafting
comes immediately in contact with the rod C.
The shank carries a piece d (figures 8 and 9) in which the hood D which surrounds
the pulley A is fitted or fixed.
A cord loaded by the weight E (Figures 2, 8, and 10) is attached to the hoop D,
and passes over a pulley e by means of which the weight of hoop D rod C and other
parts belonging thereto is balanced. A tight cord F runs along the ceiling parallel to
the shafting B. It passes over rollers and is at one end fixed to a lever H (figures
and 8) for throwing off the driving belt, and at the other end provided with a cord
tightening device. The latter is formed by passing the extremity of the cord over
an end pulley and through a fixed eye (figure 1) and attaching to its end a weight.
All the counterweights E are connected by cords (Figures 1, 2, 8 and 9) with the
tight cord which is however not affected during the regular working as the
weights are counterbalanced by the weight of the protecting device. Now if an object
be caught and carried away by shaft B, the belt or the pulley A, it must come in
contact with the connecting rod Cor with the hoop D and shift these parts upwards.
as this takes place, the end of the cord to which the weight is attached is
lowered and the weight pulls the tight cord F. The weight G is therefore raised
until it.touches the eye g, when it cannot rise any further and the weight E therefore
pulls the lever H and thereby brings the throwing off gear of the main driving belt
into action, and at the same time, causes a breaking device to act on the main driving
pulley. This throwing off gear can be actuated by mechanical, electric, hydraulic
or pneumatic power but its action must be as quick as possible so that the person
seized by the shaft etcetera, shall not be seriously injured before the motion is
stopped.
As soon
In the case under consideration, the throwing off gear is set in action by
mechanical means.
The lever H, connected to the tight cord F, (Figures 1, 2, 8 and 11), is
provided with a projection k, Figure 8, bearing against a claw on the pulley I,
connected with another pulley K. Round the pulley 1, Figures 2" and S, a
cord m passes, one end being attached thereto and the other end carrying the
disconnecting weight M, Figure 2", kept at rest by the claw held by the
projection of the lever H. A second cord n' round the pulley K carries
the weight n by means of which the claw is brought back, when desired,
against the projection K of the lever H. The weight M is connected with the
belt fork shifter N by a cord o passing over a pulley O. The other end of N
is likewise connected with a loaded cord for the purpose of bringing the said
belt shifter back to its former position, and thereby allow the driving belt to be
shifted on to the fast pulley again. The hand lever L. pulls by means of a hook,
Figure 1, the brake lever P and its brake block Qaway from the fast pulley R¹.
The mode of action is as follows:-
The projection k of the lever H holds firmly as mentioned, the claw of the pulley I,
and the brake apparatus is thereby at rest. If at the moment of danger, the cord F
be pulled in the manner above described, the lever H is drawn back and the
claw is disengaged. The weight G falls at once, and by means of the cord o, and
belt shifter N the driving belt is shifted to the loose pulley R, the hand lever L

page_text: is pulled down at the same time and releases the brake lever P, which, through the
action of the weight X applies the brake block Qagainst the fast pulley R¹.
It is advantageous to give a wedge shape to the brake block and to arrange it so
that the fast pulley itself applies the brake.
By properly calculating the weights M. and X, and giving the proper position to the
brake block, the fast pulley R and with it the whole line of shafting can be brought
to a standstill, almost immediately, so that the person in danger has time to free
himself.
When this has occurred, the inner end of the lever L is lifted by depressing its handle
and the weight M thereby raised. The counterweight of the belt fork shifter N
moves it the necessary distance to bring the belt back to the fast pulley. The brake
lever P and the brake block Q sink down in consequence of their own weight, and
the weight n turns the pulleys K and I until the claw engages the projection k of
the lever H, which a spring has brought back into its position of rest.
If now the hand lever is set free, the projection of the bar H receives again
the pressure of the weight M, and the throwing off gear cannot come into action.
If electricity is to be used to actuate this or any protecting device, the motion of
the lever I can be utilised to close a circuit, or instead of the tight cord F a con-
ducting wire may be used with advantage, and the arms of the protecting hoop D
made long enough to permit them to come to rest on the wire, or again a special rod
may be introduced between the back flanges of the clamps a, which rod is bent to such
a shape so as to form contact with the conducting wire.
In applying this modification, the protecting device can be counterbalanced by
means of weights, in the manner already described, or there can be counterweights
on the arms of the protecting hoop, or the counterweights may be arranged on rods
inserted between the flanges of the clamps a. If now the protecting device is raised,
the arms of the same or the rod adapted to the clamps a, touch the tight wire,
thereby closing the circuit, and the electric current effects the throwing off of the
driving gear.
As the protecting hoop set in motion will after turning in contact with the con-
ducting wire, probably move a little further before it stops, the protecting device would
break, if it is prevented from accomplishing this small further motion. In the
application of the aforementioned conducting wire, this draw-back is not to be feared,.
because the wire is depressed by the end of the hoop in contact with it, or by the rod
attached in the clamp a and it afterwards resumes its former position owing to its
elasticity.
If, on the contrary, the tight cord is depressed by one of the rods forming the
prolongation of the hoop D before the throw off gear comes into action, the rod must
extend beyond the cord F, sufficiently far to prevent it slipping off the same. The end
of this rod can be jointed, so that the cord F can return automatically to its proper
position as soon as the hoop D has resumed its normal position. This arrangement,
which would correspond almost entirely to that described with respect to the use of
electricity, is represented in perspective on Figure 7.
On the side opposite the hoop D) there is introduced in the clamps a, a rod Di
similar to the piece of Figure 9. This rod D' is weighted in such a manner as to
balance the weight of the hoop B, which consequently keeps the position assigned
to it. The rod B' extends a little beyond the tight cord F but can also rest lightly on
it. When electricity is applied and a conducting wire used instead, such a contact
is of course not allowable. This end of the rod B' is as shown on Figure 7, jointed
a small spring prevents the motion of the joint so that when the hoop is moving
upwards the end of the rod is stiff, and the cord is depressed. The further rotation
of the hoop D overcomes the feeble pressure of the small spring and causes the
joint to be hent, and the rod D1 passes the cord F. The jointed device of the rod D
is not represented on the drawing, because such a device is generally known and
easily understood without any further description.
The tightening of the cord F can be utilized in conjunction with the device shown

page_text: in Figs. 8, 10, & 7 to make a contact, or complete a circuit. When water, ai
pressure or explosive mixtures are employed to actuate the throw off gear, the motion
of the tight cord F or lever H can effect the opening of a water or air valve.
These devices are very suitable for workshops, etcetera, where there are several
lines of shafting and for which there must be the same number of lines of cord or
wire. Protecting devices can also be easily applied to machine tools in connection with
which workmen are easily wounded.
In a rolling mill such as that shown diagrammatically on Figures 4 and 5, the
clamps a are fixed on the axles of the rollers and the rod is so situated that only a
body of the thickness of the plate to be rolled can pass through; any other thicker
body comes in collision with the rods C, thereby moving them and bringing into
action the throwing off gear in the manner already described.
Similar to the foregoing are the protecting devices for toothed wheels, saw blades,
etcetera. It is therefore superfluous to go into any further description respecting
thern.
In cases where the driving belts cannot be shifted on a loose pulley, such as, for
instance, the belts that derive their motion directly from the engine, it is advantageous
to close the admission or regulator valve, and to effect the braking of the fly wheel
by means of the protecting device.
Figure 6 shows such an example.
The movable protection hoop C surrounds the fly wheel, and is balanced and hung
to a cord passing over rollers fixed in the ceiling, the other end of this cord being
wound several times round a disc fixed on the valve spindle.
If the engine attendant moving the fly wheel to start the engine is caught by it,
he at once cones in contact with the hoop C which then follows the motion of the fly
wheel shaft, and the regulator or valve spindle is put in motion.
the cord disc on the valve is in the proper proportion to the periphery of the fly
If the periphery of
wheel, the steam is shut off (for example when the dotted position Chas been attained),
and before the workman has been hurt.
The braking apparatus is not shown in this Figure. It could for example, be
brought into action by the striking of the hoop C against a throw off gear.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
1. In an apparatus for stopping and braking the motion of machines, shafting,
engines, gearing, and the like, the protecting hoop D, and the fence or connecting
stay C, which are arranged so as to be capable of turning on the driving shaft, but
can only move in the case of impending danger, when a person or object, caught or
carried away by the motion, comes in contact therewith, the above apparatus being
used alone or in combination with a throw or cut off gear, and braking apparatus,
substantially as described.
2. In combination with the apparatus described in claim 1, a cord F, or conducting
wire, or its equivalent, by means of which a stopping lever H is moved by the parts I
or C in the case of imminent danger, said lever releasing a mechanical throw off and
braking gear, either directly or through the medium of electricity, steam, air, or water
pressure, substantially as set forth.
300