Improvements in Furniture Castors and in the Manufacture of same.
Year: 1891

page_text: Date of Application, 10th Feb., 1891
Complete Specification Left, 14th Mar., 1891-Accepted, 9th May, 1891
PROVISIONAL SPECIFICATION.
Improvements in Furniture Castors and in the Manufacture of
same.
I, ERNEST GUSTAV HOFFMANN of 5 Clarendon Villas Beaconsfield Road,
New Southgate in the County of Middlesex, Engineer, do hereby declare the
nature of this invention to be as follows:-
My invention relates to improvements in furniture castors and in the manufacture
of same.
The castor is somewhat similar to an ordinary one in that it has a
portion or base which is affixed to the article of furniture and a portion pivoted
thereto carrying a roller. Between these two portions however I place balls or
the like for the purpose of reducing the friction between the parts and for this I
form channels in one or both of the parts for the balls to work in.
The spindle of the roller is carried in a slot in the forked portion (which is
straight) instead of in a fixed bearing so that it can roll from its centre in either
direction in order to obtain the rake necessary for producing the swivel action.
The slots may be either straight curved or angular. In the latter cases the spindle
of the roller will be brought to the centre of said slot by the weight of the article
of furniture when at rest.
In place of carrying the spindle of the roller in slots it may be carried by
pivoted arms or cranks or by similar means which will allow it to be thrown out of
its centre.
In the manufacture of my improved castor I stamp the parts from sheet brass
or other suitable metal and subsequently shape same by suitable punches dies or
the like.
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, Applicant's Agent.
COMPLETE SPECIFICATION.
Improvements in Furniture Castors and in the Manufacture
same.
of
I ERNEST GUSTAV HOFFMANN of 5, Clarendon Villas Beaconsfield Road
New Southgate in the County of Middlesex 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 :-
My invention relates to improvements in furniture castors and to the manu-
facture of same. The castor is somewhat similar to an ordinary one in that it
has a portion or base which is affixed to the article of furniture and a portion
pivoted thereto carrying a roller. Between these two portions I place balls or
the like for the purpose of reducing the friction between the parts and for this I
form channels in one or both of the parts for the balls to work in.
The spindle of the roller is carried in a slot in the forked portion (which is
straight) instead of in a fixed bearing so that it can roll from its centre in
either direction in order to obtain the rake necessary for readily producing the
swivel action.
The slot in the forked portion or "horn" is curved or angular so that the roller
will be brought to the centre of same by the weight of the article of furniture
when at rest. In place of carrying the spindle of the roller in slots it may be
carried by pivoted arms or cranks or by similar means which will allow it to be
thrown out of its centre and returned thereto.

page_text: }
In the manufacture of my improved castor 1 stamp the parts from sheet brass
or other suitable metal and subsequently shape them by suitable punches, dies and
the like.
To clearly explain the nature of my invention I will describe it with reference to
the accompanying drawings in which
Figure 1. is a front view in section of my improved castor.
Figure 2. is a side elevation.
Figure 3. is a front view in section of a castor provided with an alternative
-arrangement for carrying the roller and
Figure 4. is a side elevation of same.
In Figure 1. the castor, has, the usual base a carrying a screw for attaching it to the
article of furniture, said, base a having an annular groove or race formed on the
under side of same for. receiving the anti-friction balls b. which also bear on
the, upper. surface of the "horn portion c. This horn portion is provided on
either side with curved slots d. as shown which carry the spindle f. of the roller
the metal of said slot. being stamped out in the process of manufacture and turned
up to form an increased bearing portion e. for the spindle. In this way the horn
portion may be of comparatively thin metal which it could not well be, if the
spindle. had its bearing only on the edges of a cut slot. To strengthen same the
horn is bent and hollowed as shown, during the pressing. The slot d. it will be
seen is curved so that the spindle f. will be brought back by the weight of the
article directly under the vertical pressure exerted upon it which is not the case
- with the usual curved horn of the ordinary roller castor the tendency of the weight
on which is to break them off from the vertical spindle.on which they turn. "The
balls b. also as will be seen form an increased bearing surface which is of assistance
in taking: some of the pressure from the vertical spindle.connecting the base a and
the horn c. The slot d. may be angular or of inverted V shape instead of curved
though it is not so desirable.
In Figures 3. and 4. I pivot cranks g. g. to the arms of the horn at the points h. h.
said cranks carrying the spindle f. of the roller at their other ends. This accom-
plishes the same result as the curved slot as the crank will fall back into its vertical
position and bring the spindle of the. roller directly beneath the vertical pressure
as soon as the article of furniture is ceased to be moved.
In these figures a stamped or drawn cup portion i. is shown instead of the base a.
...and screw, said cup portion having the groove or race for the balls.
I would have it understood that I do not claim the use of balls placed between
the base, and the horn of roller castors neither do I claim broadly the stamping of
the parts nor the slotting of the bearing of the roller spindle all of which I am
aware has been suggested but,
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A castor. having, the spindle of its roller carried in a curved or: angular slot
substantially as and for the purposes described.
2. A castor having its roller, carried by cranks or otherwise so that, it will, be
brought back directly under the vertical pressure exerted upon it substantially as
. described.
3. In the manufacture of roller castors-forming the horn portion by stamping and
pressing it into the shape substantially as described and illustrated in Figures 1
and 2.
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4. The improved castors substantially as described and illustrated.
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Dated this 14th day of March 1891.
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, Applicant's Agent.