IMPROVEMENTS IN CLUTCHES
Year: 1884

page_text: I HENRY JAMES HOGG KING Engineer Newmarket near Stroud Gloucestershire
do hereby declare the nature of my invention for IMPROVEMENTS IN CLUTCHES
to be as follows:-
This Invention relates to Improvements in Ratchet Clutches.
In the ordinary Ratchet Clutch when the pawls are moving slower than the
ratchet teeth, the pawls rise and fall as the teeth pass by them producing when the
teeth are running much faster than the pawls a great deal of noise, and wear and
tear so much so that a heavy clutch soon wears itself out. There is also a tendency
in the ordinary ratchet clutch, if more than one pawl is used, for some of the pawls
to get properly into gear, and one or more of the others to catch on the points of
the Ratchet Teeth or not get into gear at all. & my Invention has for its object
the correction of these defects and includes a plan for the more perfect lubrication
of the working parts, (which portion of the Invention is also applicable to Friction
Clutches.
In the Ratchet Clutch I prefer to make; I use two pawls, which are centred
diametrically opposite each other, and which are coupled together by a connecting
rod, so that one cannot move in or out of gear without the other. The weight of
each pawl is also nearly counterbalanced by a tail so that the pawls have only a
slight tendency to keep themselves out of gear, by vertue of centrifugal force.
When running under these circumstances, if the pawls run slower than the ratchet
teeth, they will be lifted out of gear, and will remain out even though the pawls
should begin to run faster than the teeth & in order to put these pawls into gear
(which for the future I shall call the large pawls) I employ a small pawl or pawls
connected with the large ones in such a manner, that they throw the large ones
into gear, for when the speed of the pawl portion of the clutch exceeds the Ratchet
portion the small pawls come into contact with some small ratchet teeth (small
duplicates of the large ones,) and throw the large pawls into gear.
When the pawl
portion of the clutch runs slower, than the Ratchet portion a friction ring or clip
something like an Eccentric Strap, and which works on the ratchet portion of the
lutch keeps the small pawl or pawls from riseing and falling over the small Ratchet
teeth, and at the same time helps to keep the large pawls out of gear consequently
[Price Bid

page_text: there is no wear beyond the slight amount on the friction clip and no noise
whatever. The only condition to be complied with being that the Friction of the
Clip or ring must be sufficient to overcome the tendency of the small pawl to fall
into gear.
This friction ring forms an essential part of my Invention as the arrangement
and position of the pawls may be varied, and the small ones may be dispensed with
but in all cases the large pawls are put into gear through the agency either
indirectly or otherwise of the Friction Ring or Clip-In order to make the friction
as uniform as possible I prefer to produce the friction by means of a brass plate,
kept at an uniform pressure, by a spring which works inside the friction clip.
Dated this first day of February 1884.

page_text: I, HENRY JAMES HOGG KING, Engineer of Newmarket Near Stroud, Gloucester-
shire do hereby declare the nature of my invention for IMPROVEMENTS IN CLUTCHES
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:―
In the ordinary Ratchet Clutch when the Pawls are moveing slower than the
ratchet teeth, the pawls rise and fall as the teeth pass by them, producing when the
teeth are running much faster than the pawls, a great deal of noise and wear and
tear, so much so that a heavy clutch soon wears itself out.
There is also a tendency in the ordinary ratchet clutch, if more than one pawl is
used for some of the Pawls to get properly into gear, and one or more of the others
to catch on the points of the Ratchet teeth or not get into gear at all, and my
Invention has for its object the correction of these defects. In the Ratchet Clutch
I prefer to make I use two pawls, which are centred diametrically opposite each
other, and which are coupled together by a connecting rod so that one can not
move in or out of gear without the other The weight of each pawl is also nearly
counterbalanced by a tail so that the pawls have only a slight tendency to keep
themselves out of gear by virtue of centrifugal force when running. Under these
circumstances if the pawls run slower than the ratchet teeth they will be lifted out
of gear and will remain out, even though the pawls should begin to run faster than
the teeth & in order to put these pawls into gear (which for the future I shall call
the large pawls,) I employ a small pawl or pawls connected with the large ones, in
such a manner that they throw the large ones into gear for when the speed of the
pawl portion of the clutch exceeds the ratchet portion the small pawls come into
contact with some small ratchet teeth (small duplicates of the large ones) and
throw the large pawls into gear When the pawl portion of the clutch runs slower
than the ratchet portion a friction ring or clip something like an Eccentric Strap
and which works on the Ratchet Portion of the clutch, keeps the small pawl.or
Pawls from riseing and falling over the small ratchet teeth, and at the same time
helps to keep the large pawls out of gear consequently there is no wear beyond the
slight amount on the friction clip and no noise whatever, The only condition to
be complied with being, that the friction of the ring or clip must be sufficient to
overcome the tendency of the small pawls to fall into gear.
This friction ring forms an essential part of my Invention, as the arrangement
and position of the pawls may be varied and the small ones may be dispensed with
but in all cases the large pawls are put into gear, through the agency either
indirectly or otherwise of the friction ring or clip. In order to make the friction
as uniform as possible, I prefer to produce the friction by means of a brass plate
kept at an uniform pressure by a spring which works inside the friction clip and
in order that this Invention may be more fully understood, I have appended hereto
a Sheet of Explanatory drawings.
Fig 1 & 2. show an Elevation and Section of the clutch I prefer to make.-
1 & 2 are the large pawls, which are shown in gear with the ratchet portion of tho
clutch 3. These pawls are centred on the pins 4 & 5 but the working strain is
borne by the main casting at 6 & 7. These pawls are nearly balance weighted by
the tails 8 & 9, and it will be noticed they are coupled together by the connecting
rod 10 so that one can not move without the other. These large pawls carry
smaller ones 11 & 12 which are centred on the pins 13 & 14. These small pawls
engage, with the ratchet teeth 15, which are small duplicates of the large ones 3-
If we now suppose that the Ratchet portion of the clutch, begins to move faster
than the pawl portion, the large pawls will be lifted out of gear by the teeth 3
passing under them and will remain out without any tendency on their part to fall
in again-The small pawl 11 which is kept up to its work by the spiral spring 16

page_text: has however always the tendency to fall into gear, and would continuously rise and
fall over the small teeth, were it not kept clear of them by means of the friction
clip 17 a portion of which 17' comes into contact with 18, and the friction of the
clip being sufficiently great to overcome the resistance of the spring 16 the pawl
is kept clear of the teeth 15. (The necessary friction of the clip 17 is produced
by the brass 19 which is kept in contact with 3 by the spiral spring 20.
If we now suppose the pawl portion of the clutch to begin to move faster than
the ratchet portion 18 will move away from 17 and 11 will be caught by the
first ratchet tooth 15 which presents itself. This will at once throw the large
pawls 1 & 2 into gear, and owing to the shape of the teeth and arrangement of
.centres, when the large pawls are in gear the small ones are clear of the teeth 15,
so that no strain comes upon them beyond putting the large ones into gear. In
the event of the spring 16 failing the small pawl 11 is thrown into gear by the
projection 21 on the friction clip 17, coming into contact with the arm 18. The
small pawl 12 is a duplicate of 11, and is usually fitted to these Clutches to give
extra security Figs 3 & 4 show an Elevation and Section of a 'Ratchet Clutch in
which the small or Secondary pawls 'for throwing 'the 'large ones into gear are
dispensed with. In this case the pawls are attached directly to the friction ring 17
by means of the Connecting Rods 22 & 23, or the pawls may be made like bell
cranks as shewn in dotted lines at 24 & 25. If two or more pawls are used in this
arrangement each pawl must be attached to a separate friction ring as shewn @ A.
Fig 4 or the friction ring may be made in lengths and fitted 'to dovetail pieces as
shewn in Section @ B, a pawl being attached to each length so that each pawl and
its friction ring may act independently of the others. The object of this is to avoid
'breakage for if one pawl should slip into gear, and the others should fail to do so
breakage must result if they are both attached to the same rigid ring. Another
plan to avoid breakage is to make the connecting rods, or bell cranks sufficiently
elastic (by springs as to allow them to yield and not break-When a bell crank
pawl like 24 is used a spring must be introduced to give 'the pawl a 'tendency to
fall into gear.
Having now particulary described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
1st The use in a Ratchet Clutch (of a frictional arrangement) such as the friction
ring or clip shewn in the drawings which shall act directly or indirectly on the
pawl or pawls with sufficient force to keep them clear of the Ratchet teeth when
the pawls are running slower than the ratchet teeth, and which will put the pawls
gear when they begin to run faster than the ratchet teeth.
into
2nd The use of a Secondary pawl connected with the primary or large pawls in
such a manner as to throw them positively into gear, without any liability of their
catching on the points of the teeth.
3rd The use of a connecting rod or its equivalent, to couple two or more pawls
together in such a manner, that the group coupled together shall go into gear @
the same time.
4th The use of Friction rings in duplicate or in Sections as described in relation
to Figs 3 & 4 so that each pawl, can act independently of the others and thus
avoid breakage, also the use of Spring connecting rods or pawls as described to
effect the same purpose.
Dated this 21st day of October 1884