Year: 1840

page_text: MACKELCAN & MURDOCH'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS' SHALL COME, we, FREDERICK
PAYNE MACKELCAN," of Birmingham, in the County of Warwick, Civil
Engineer, and JAMES MURDOCH, of Hackney Road, 'in the County of
Middlesex, Civil Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by 'Her.
Letters' Patént: under the Great Seal of Great Britain, bearing date at West-
minster, the Twenty-third day of December,' in the fourth year of -Her reign,
did, for Herself, Her heirs and successors, give. and 'grant unto us, the said
Frederick Payne Mackelcan and James Murdoch, our exors, adñors, and
assigns, Her especial licence, full power, sole privilege and authority, that we,
the said Frederick Payne Mackelcań and James Murdoch, our.exors, admörs,
and assigns, or such others as we, the said Frederick Payne Mackelcan and
James Murdoch, our exors, admors, or assigns, should at any time agree with;
and no others, from time to time'and at all times hereafter during the term of
years therein mentioned, should and lawfully might inake, use,. exercise, and
vend,' within England, Wales, and the Town of Berwick-upon-Tweed, the

page_text: Invention of "CERTAIN IMPROVEMENTS OF OR BELONGING TO TABLES, A PORTION OF
WHICH IS APPLICABLE TO OTHER ARTICLES OF FURNITURE," being partly commu-
nicated from a certain Foreigner residing abroad; in which said Letters
Patent there is contained a proviso that we, the said Frederick Payne
Mackelcan and James Murdoch, or one of us, shall cause a particular
description of the nature of our said Invention, and in what manner the same
is to be performed, by an instrument in writing under our hands and seals, or
the hand and seal of one of us, to be inrolled in Her said Majesty's High
Court of Chancery within six calendar months next and immediately after the
date of the said in part recited Letters Patent, as, upon reference thereunto,
will fully appear.
NOW KNOW YE, that in compliance with the said proviso, we, the said
Frederick Payne Mackelcan and James Murdoch, do hereby declare that the
nature of our Invention consists in improvements in the construction of bed
and sea tables, likewise in table castors and table fastenings, a particular
description of which, illustrated by Drawings, is hereunto annexed. .
The improved bed table is intended to be used by a person while in bed.
The side elevation is shewn in Figure 1, and the end elevation in Figure 2.
The part A, B, or A, H, passes over the bed, while the part D, E, passes
under it. The portion of the top from B to A is consequently in front of the
person in bed, and at the same time is well supported by the projecting base
beneath. The framing, which is principally made of metal tube, is in two
parts, A, C, I, H, and H, I, F, D; and the upper part may be raised or
lowered as the tubes B, H, and C, I, pass down inside the tubes H, G, and
I, F, and slide in them. The upper part is fixed at any height by four small
pins passing through the tubes where the sliding takes place. The form of
bracing which gives the table strength is what is commonly termed a truss.
A, H, and C, H, form the struts; A, C, the tie; and B, H, the king post of
the upper portion D, E; and F, E, the struts; D, F, the tie; and E, G, the
king post of the lower part. The braces H, F, and I, E, merely serve to
keep the uprights parallel and steady. This system of bracing by a truss may
be applied to other furniture, as, for example, a bedstead; Figure 3, where
A, B, and C, B, are the struts; A, C, the tie; and D, B, the king post.
The improved ship table is intended to be used at sea, and is so constructed
as to keep everything level that is on it, notwithstanding the motion of the
ship.
Figure 4 is a side elevation when the cabin floor is level; and Figure 5 is.
the same when the floor is not level. A, Figure 4, is the top, which is cut
into small pieces, each sufficient to hold a plate or dish, as is shewn in

page_text: Figure 6, which is a plan. Each of these pieces at top has a little ball affixed
to the under side, and from the bottom of this ball there proceeds a rod or
stem downwards. B, Figure 4, is the main frame, and is shewn in plan,
Figure 7. It is a square or oblong, divided by cross bars into compartments.
A little above the centre of each compartment is a small cup, supported by
four rods from the four corners of the compartment. The cups are hemi-
spherical, with an aperture in the bottom; the position of them horizontally
may be seen in Figure 7, and their height above the main frame in Figure 4,
where they are seen immediately under the top. C, C, Figure 4, is another
frame, the plan of which is Figure 8. This frame, by way of distinction, is
called the governor. D, Figure 4, is a small platform with weights upon it,
shewn in plan in Figure 9. The relative position of these various parts, and
the motions of some of them, are as follows:-Each ball rests in a cup, and
the stem passing through the bottom of the cup enters a hole in the governor.
The four stems at the four corners of the table belonging to the divi-
sions E, F, G, H, of the top, Figure 6, have a nut at the lower end, so that
the governor is suspended by them. The four middle stems belonging to
divisions I, J, K, L, are larger than the rest, and sustain the platform on
which the weights rest. The motion is thus:-When the floor becomes
sloping the platform D swings to one side, until the stems by which it hangs
are upright. These four stems move the governor with them, and the
governor moves all the other stems with it; thus they all become upright.
The divisions of the table top are fixed at right angles to the stems; and the
stems being upright, they must of necessity be level. The same principle
is applicable to any other article of furniture, as, for example, a berth,
Figure 9, A.
The improvements in table castors we shall now describe.
Figure 10 exhibits an elevation, and Figure 11 a vertical section of a
castor, especially designed for metallic furniture, but equally adapted to furni-
ture made of wood. It consists of an iron screw pin with a conical head,
resting and working in a conical cup at the junction of the horns. The top of
the cone, which is downwards, is made cylindrical, and receives a small ring or
ferrule with a pin through it to prevent the cup and horns from falling off.
The degree of taper in the head of the screw pin may differ, as shewn in
A, B, C, Figure 12. The peculiarity of this castor is, that it has only one
rubbing surface (independent of the axis axis of the bowl), namely, that of the
cone, which, by its oblique position, receives both the downward and lateral
pressure. This cone also serves the purpose of the usual vertical pin, but is so
strong from its form that it can neither be bent nor broken.

page_text: Figure 13 exhibits an elevation, and Figure 14 a diametrical section of a
castor having two concentric sockets, one of which is fixed to the leg of the
table, and the other revolves around it, together with the horns and wheel.
The horns are consequently not as heretofore a separate piece of metal jointed
to the socket, but they are made in one solid piece with the socket, conferring
thereby a degree of strength never before obtained: At aa, is the revolving
socket cast in one piece; or otherwise made solid with the horns 6, 6, that
carry the axis c of the wheel d. The. fixed socket is shewn at e, having á
point f; which turns- in an oil cup 9, formed to receive it in the revolving
socket a, and so that the vertical pressure shall be sustained upon the apex of
the inverted cone. Around the upper edge of the fixed socket is an annular
projection h, which, when a lateral pressure is exerted, just touches the-inner
circumference of the revolving socket; and as these parts have to sustain the
lateral friction, they are turned; polished, and lubricated: The friction and
pressure therefore in this castor are sustained by the strongest parts of the
structure instead of the weakest, as is the case in the common castor, where the
whole weight, increased in intensity by the leverage of the horns; is made to
impinge upon the edge of the collar-next to the, vertical pin; and which, as is
well known, rapidly destroys or cripples it. It should be noticed, that there are
two-modes provided for fixing this improved castor,-first, by unscrewing the
plug-k, the hole 7 is opened for the insertion of a turnscrew to turn a screw
into the wood, which, being done, the castor is to be turned round till another
screw hole presents itself, as that shown with a screw in it on the opposite the
side: If any circumstance should render this mode difficult, the lower part of
revolving socket a may be unscrewed at m, from the upper, and the lower
portion of it removed until the interior socket is satisfactorily fixed.
Figure 15 exhibits another modification of the principle of the double-socket
castor, in which (instead of a pivot) a pin is made the centre of motion
of the revolving socket as well as the means of connecting the two sockets
together. For screwing on the fixed socket, a passage for the screw-driver is
made through the bottom of the socket to the screw holes, as shewn at e in
the Figure: In other respects this castor is essentially the same as that pre-
viously described under Figures 13 and 14. To allow of the separation of
the sockets, if required; the bottom of the pin may bé fastened by a screwed
'nut.'
he
Figure 16 exhibits a diametrical section of a castor, the mechanical action
of which is nearly similar to the foregoing, but is adapted for less weighty or
'inferior furniture. At a is an iron collar, which is to 'be first screwed to the
leg of the table. b is a socket made in one piece with the horns, which is

page_text: next to be placed on the leg with its periphery c,. c, under the flange of the
collar a. Then a hole is to be bored up the leg of the table, into which is to
be turned the strong screw d, the polished lower end of which becomes the
centre of 'motion of the socket. A rounded washer e is put upon the screw
inside the socket to keep the wood from rubbing against the bottom. The
inside of the head of the screw (which should also be provided with a smooth
washer) thus sustains the vertical while the collar sustains the lateral pressure
and friction.
..
Figure 17 shews an elevation of a castor, having precisely the same
mechanical: arrangements as the last mentioned, but designed for furniture
that will admit of but little elovation. In the construction of castors with two
sockets it is not essential that the fixed socket should be entirely sunk within
the revolving one, as it may be partially or almost wholly raised above it, as is
sufficiently illustrated by the Diagram Figure 18 A, wherein the moveable
socket a is shown as connected to the fixed socket 6 by an annular turn over
of the edge of the metal of the moveable one into a circular groove c made
around the fixed one, by means of pressure with a burnisher (an operation' too
well known to brassfounders in shell work to need explanation here); but as
the thickness of metal to be turned over should be, somewhat greater than
ordinary, a rubbing tool of greater efficacy or leverage than the common
burnisher is, desirable. The necessity of any turn over is however obviated by
connecting the revolving and fixed portions of: the castor by means of an axle
pin, as in the case of Figure 15. It may be further noticed, that the leading
object of the preceding mechanical arrangements is to cause the lateral friction
to be thrown as remotely as practicable from, the centre of motion or pivot.
And this object may be obtained by a further modication of the Plan.exhibited
in Figure 18 A, by making the bottom only of the socket revolve along with
the horns. Thus a, Figure 18 B, will represent the fixed socket 6; the bottom
and horns, with an inclined periphery c, c, the extreme edge of which is made
thin, and turned into a groove in the socket a, to keep 6 and. ȧ together, with
the-inclined faces just clear of absolute contact.:s If the mechanical action of
this castor is not quite so favorable in point of leverage as the former described,
the superior convenience it affords of fixing. may! be deemed an" equivalent.
In the application of these improved socket castors to metallic furniture the
socket will be shorter, cylindrical, and otherwise adapted thereto, similar to
the socket shewn at Figure 30.
.
:
Figure 19 exhibits a section, Figure 20 a side elevation, and Figure 21 a
front elevation of a castor, provided with two running wheels or bowls, the

page_text: axle of which is mounted in an axle block between them. The fixed socket a
is united to the revolving one in the same manner as delineated, or it may
be without a turn over of the metal, as before explained. To the bottom of
the revolving socket, instead of the usual horns, is cast a single descending
pillar or axle block c, which necessarily revolves also. At d is a pivot, whose
. upper end is fastened in the bottom of the fixed socket a, and whose lower
conical extremity rests in a small pivot hole of the revolving axle block c.
e, e, are the two bowls revolving freely upon their axis f, which passes through
the axle block.
Figure 22 shews a side elevation, Figure 23 a section, and Figure 24 a
front elevation of a castor, provided, in addition to a pair of running wheels (as
in the last described), with an antifriction roller, which, while it entirely
prevents all lateral friction, confers upon the castor an extraordinary degree of
strength and facility of motion. At a is a common socket having a pivot b,
the conical extremity of which rests in a pivot hole made in the axle block c.
d, d, are the bowls which revolve freely on their pin e. Atf is a strong anti-
friction wheel, the axis g of which is a stout pin screwed into the solid metal
of the axle block, but having its extremity (reduced and polished) so far pro-
truding into an annular groove in the vertical pivot b as lightly to garter it;
and prevent the lower part of the castor from dropping off when the furniture
may be lifted from the floor. By this addition of the wheel fit will be noticed
that the previous oblique direction of the force is changed entirely into the
vertical, that the friction arising from the weight upon the leg of the table,
when the same is turned, is supported upon two points, namely, the point of
the pivot and the periphery of the antifriction wheel, consequently there cannot
be any lateral friction, there being no oblique or lateral surfaces in motion that
even touch each other. The whole weight or force being thus directed entirely
upon the horizontal axles of the wheels confers such strength and smoothness
of action that castors on this principle may be made of much less weight than
others, to sustain and work under any given load.
Figures 25, 26, 27, 28, are designed to shew the application of the same
combination of wheel work to that denomination of castors distinguished by
the term "plate castors." Supposing the sockets in Figures 22, 23, and 24 to
be removed, it will be observed that there will remain essentially the same
mechanism to work the plate castor, as delineated in Figures 25, 26, and 27
(Figure 28 being merely a plan of the same plate castor). The correspondence
of the various parts in these several Figures are also indicated by the recur-1
rence of the same letters of reference. But as plate castors are usually

page_text: applied to heavier and coarser articles than socket castors, they are conse-
quently chiefly made of iron, of greater massiveness and with less regard to
finish.
Figure 29 is merely introduced to shew that plate castors of this novel kind
are owing to the position and form of the axle block adapted to receive wheels
of great diameter without raising the furniture to an extraordinary height,
thus affording the facility of rolling over very thick carpets, or where there are
no carpets of surmounting very considerable asperities or irregularities of
surface. It would also be proper to notice, that the circular form in the cross
section given to the bearing periphery of the bowls, as shewn at O, O, in
Figure 29, is preferred in all cases where the surface rolled upon is sufficiently
hard to prevent any permanent indentations.
Figure 30 shews the application of the same kind of castor to metallic
furniture, whether solid or hollow. To the top of the plate is merely cast a
short ornamental hollow case, into which the solid or hollow leg is put and
pinned through.
The improved table fastening is delineated at Figures 31 and 32, Figure 31
being a plan, and 32 a side view. At a is a metallic plate, which is to be
screwed upon one of the leaves or flaps of a table, and to this plate is cast a
solid picce of the segmental form delineated at b. To the other flap of the
table, which is to be connected to the former, is to be screwed the plate c, and
to this plate is fixed a stout vertical pin d, which forms the axis or fulcrum of
a lever (of the second class) represented by d, e, f. g is a flat steel spring, one
end of which is fixed round a pin h, and the other end bears against a stop i.
The end d of the lever is formed into a square-faced block rounded off at the
corners; one of the flat sides of this block (as shewn on the plan by dots),
comes into contact with the spring, which holds the lever in the position drawn
(i.e. the fastened position), and when it is turned back (or unfastened), as
shewn by the dotted lever d, e, f, the spring acts on another of the flat sides of
the lever block, and retains it in that position with the desired force. At h is
an antifriction roller, which, when the lever is turned in the direction indicated
by the arrow, rolls against the curved surface of the segmental block which
surface presents the point of resistance in every position of the lever. The
curve of this surface is the arc of a circle struck from the point i, consequently
it is eccentric to the curve described by the motion of the lever. The lever,
therefore, in causing the roller h to roll over the segmental curve, progressively
draws together and unites the two flaps or leaves of the table or tables. Atj
is a stop to prevent the lever being needlessly forced. To shew that this table
fastening is susceptible of various modifications without departing from its

page_text: -peculiar characteristics, Figures 33, 84, and 35. have been added. . These
fastenings are worked by levers of the first class, or that kind wherein the
fulcrum (d) is situated between the power (f) and the resistance (e). .
In-Figures 33 and 34, which is a plan and elevation of the same fastening; the
antifriction roller is mounted on one of the plates; but in Figure 35 the roller
is attached to the resisting end e of the lever, which arrangement bringing the
resisting point nearer to the fulcrum than in the previous arrangements confers
upon this fastening the advantage of greater power or leverage than the
others.
Haying now explained the nature of our improvements of or belonging to
tables, and given a particular description of them, we desire it to be distinctly
understood that we do not claim all and every part of the same which have
.been introduced-into our Drawings and description.
.
3.
.1
But what we do claim as original are as follows: The bed table and its
system of bracing as applicable to other furniture; also the ship table and its
principle of construction as applicable to other ship's furniture.
As respects the castors, we claim,—,
......
First, the solid conical head working in a conical cup or socket at the
junction of the horns....
2
Second, the construction of castors in which the socket and horns are
united in one solid piece, or that variation of construction explained with
reference-to-Figures 18 A. and 18.B.
.
Third, the fixed metallic collar illustrated by Figure 16. .
Fourth, the application of a pair of running wheels to castors."
Fifth, the combination of the last mentioned with an antifriction roller.
As respects the table-fastening,-
-9...".
First, the application of an antifriction roller to levers of the first or second
class at the point of resistance, whether the said roller be mounted upon the
moveablo or stationary parts.
:
'Second, the same principle of construction of fastening, supposing that
sinstead of the rolling surface of a roller a rubbing surface be applied in lieu
thereof.. 4.
ン
...
* 2.
".
In witness' whereof, we, the said Frederick Payne' Mackelcan" and
James Murdoch, have 'hereunto set our hands and seals, this Twenty-
...first day of June, in the year of our Lord One thousand eight
hundred and forty-one.
(L.8.) MACKELCAN
FREDER
AINE
JAMES (L.s.) MURDOCH.

page_text: AND BE IT REMEMBERED, that on the Twenty-first day of June, in
the year of our Lord 1841, the aforesaid Frederick Payne Mackelcan came
before our said Lady the Queen in Her Chancery, and acknowledged the
Specification aforesaid, and all and every thing therein contained and specified,
in form above written. And also the Specification aforesaid was stamped
according to the tenor of the Statute made for that purpose.
Inrolled the Twenty-second day of June, in the year of Our Lord One
thousand eight hundred and forty-one.