Improvements in Means for Producing Adhesion between Chains and Pulleys or between other like Pieces of Mechanism.
Year: 1891

page_text: Date of Application, 18th Aug, 1891-Accepted, 19th Sept., 1891
COMPLETE SPECIFICATION.
Improvements in Means for Producing Adhesion between Chains
and Pulleys or between other like Pieces of Mechanism.
1 JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of
Middlesex Gentleman do hereby declare the nature of the said invention which
has been communicated to me from abroad by Armand de Bovet of 47 Rue
Taitbout, Paris in the Republic of France Engineer and 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 means for producing adhesion between two pieces of
mechanism such as a chain or wire rope and a pulley or drum and may be employed
with great advantage whenever it is desirable or necessary to provide means for
causing the two parts such as the chain and the pulley to adhere strongly together
and at the same time to enable such parts to be released by causing the adhesion
to cease suddenly or otherwise.
The invention consists in constructing one of the two parts in such a manner as
to admit of imparting to it the properties of an electro-magnet which may be
rendered active or inactive as desired that is to say is capable of being magnetised
or de-magnetised by the action of an electric current so as to attract or release
the other part in the same way as the armature of an ordinary electro-magnet can
be alternately attracted and released.
For the purpose of magnetising or demagnetising the pulley or other like piece
of mechanism to which the invention is applied I may employ any suitable
arrangement enabling the circuit of the electric current circulating in the coils of
the electro magnet to be regulated or alternately opened and closed so as to
regulate or interrupt the current flowing in the said coils.
In order to obtain the best result it is desirable to so arrange the part performing
the function of the electro-magnet as to enable the part attracted to be charged to
saturation.
And in order that the said invention may be fully understood I shall now proceed
more particularly to describe the same and for that purpose shall refer to the
several figures on the annexed sheet of drawings the same letters of reference
indicating corresponding parts in all the figures.
Figure 1 of the accompanying drawings represents in side elevation a drum or
pulley such as is employed in vessels used for towing barges or the like by means
of a submerged chain.
Figure 2 represents the pulley in front elevation partly in section.
Figures 3 and 4 are similar views partly in section illustrating a modified form
of pulley and
Figure 5 illustrates another arrangement in elevation.
According to the arrangement illustrated in Figures 1 and 2 a series of horseshoe
electro magnets is employed the said magnets being arranged on each side of the
pulley as represented in Figure 2 and provided with coils 1 and yokes 2. The
periphery of the pulley is divided radially into a number of segments 3 connected
to the legs or branches of the magnets so as to form pole pieces being. suitably
insulated by radial plates a (Figure 1) of brass or other non-magnetic material
and by a non-magnetic ring or washer 6 Figure 2. The said pole pieces or
segments 3 form the peripheral groove of the pulley for the reception of an iron
chain 4 the links of which close the magnetic circuits and the general arrangement
of the coils and magnets resembles that of the electro magnets in a Siemens dynamo
or electro-magnetic machine working with alternate currents.
The chain being carried partly round the pulley as represented in Figure 1 for

page_text: example it is evident that by causing an electric current to circulate in the coils 1
of the electró magnets the pole pieces or segments 3 forming the groove of the
pulley may be magnetised so as to cause the chain 4 to adhere strongly to the
pulley and effectually prevent any slipping of the said chain upon the said pulley
and by 'regulating or diverting the current the magnetisation of the pulley and
consequently the adhesion of the chain due to the magnetisation may be controlled
or arrested as required."
According to the arrangement illustrated in Figures 3 and 4 the pulley is formed
by two discs 5 bolted together they being magnetically separated by a ring band
presenting a groove forming an annular space for the reception of a coil or bundle
of wire M. This combination forms an annular electro-magnet the poles of which
form the periphery or groove of the pulley as indicated at N S Figure 4. The
action of this pulley is controlled by means of the current circulating in the coil M
as hereinbefore described with reference to Figures 1 and 2.
Figure 5 illustrates another arrangement according to which a series of horseshoe
electro-magnets is arranged with the legs or branches of the said magnets in a
radial position in the pulley the yokes 2 being at the centre and the pole pieces N S
forming the periphery or groove of the pulley. The general arrangement of the
coils in this pulley resembles that of the coils in an alternate current Gramme
machine.
When applied to the chain pulleys of vessels employed for towing purposes this
invention presents the advantage of enabling the necessary adhesion between the
chain and the pulley to be obtained without rendering it necessary to cause the
chain to embrace a large portion of the periphery of the pulley and thus facilitates
the operations of shipping and unshipping the chain and dispenses with the necessity
for hauling a great weight of chain on board of the towing vessel.
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. The improved means for producing adhesion between chains and pulleys or
the like by the action of electro-magnets arranged and operating substantially as
hereinbefore described.
2. The combination of a pulley and chain with means for magnetising the groove
of the pulley so as to cause adhesion between the said pulley and the chain
substantially as hereinbefore described with reference to the accompanying
drawings.
3. The combination of a pulley and chain or other equivalent pieces of
mechanism with means for increasing or regulating the amount of friction or
adhesion between them by the action of electro-magnets substantially as herein-
before described with reference to the accompanying drawings.
4. The several arrangements and combinations of parts constituting electro-
magnetic pulleys or pulleys provided with means for magnetising the grooves
thereof substantially as hereinbefore described & illustrated in Figures 1 and 2, 3
and 4 and 5 respectively of the accompanying drawings.
Dated this 17th day of August 1891.
J. H. JOHNSON & Co.,
Agents for the Applicant.