Improvements in Frames for Cycles and similar Machines, Motor Cars, or Carriages.
Year: 1898

page_text: Date of Application, 12th Dec., 1898
Complete Specification Left, 12th Sept., 1899-Accepted, 14th Oct., 1889
PROVISIONAL SPECIFICATION.
Improvements in Frames for Cycles and similar Machines, Motor
Cars, or Carriages.
I, CLAUDE WILLIAM ATKINSON, of Glendale, Woodland Place, Penarth, in
the County of Glamorgan, Civil Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention relates to bicycles, tricycles, and similar machines or motor
cars or carriages, and has for its object the arrangement and construction of
those parts of these machines which form the framing on which the load is
carried and supported on the axles on which the wheels revolve, whereby con-
siderable decrease in weight of these part can be obtained without reduction in
strength, and also reduction in cost of manufacture is effected.
Structures of this kind are in general built up of several members which when the
structure is loaded are subjected to forces tending either to stretch, compress or
bend them, and the different members must be sufficiently strong to resist these
forces. The actual magnitude of the forces is usually comparatively small, when
these forces are those of simple tension or compression, so that were the mem-
bers of the structure liable to be subjected to these simple forces only, the cross
section of the material of which they are composed might be small. In the
frames usually built however, the various members of the structure are not
in general subject to forces of simple tension or compression only. This arises
either from the structure not being so perfectly braced as to avoid completely
having bending actions on some of the members when the load is applied, or
frequently variations in the position of the load or alterations in external forces
due to the actions when in use, cause members which have previously been in
tension to become in compression or vice versa, or to be subject to bending
moments. In addition to this, forces not due to direct loading of the structure
in the usual way, may be either accidentally or purposely applied transversely
to some of the members, subjecting them to bending actions.
On account of these several reasons it is necessary in the frames usually built,
to make the several members of such sizes and shapes as will allow of members
which under normal conditions would be subject to tensional forces being put
into compression, and will also allow of bending actions being applied to any
of them; and on this account the amount of material required to resist these
variations in direction of the forces or these bending actions, is largely in excess
of what would be required to resist simple forces of tension or compression
only.
In order to prevent the collapse of the structure when loaded, owing to
imperfect bracing, the joints between the adjacent members are made rigid
either by means of brazing or rivetting or the like which is liable to reduce the
strength of the material, or by means of rigid junction pieces to which the adja.
cent members are separately and rigidly attached, which causes additional
weight of material to be used.

page_text: My invention consists in means for overcoming these difficulties, whereby
the amount of material required in the structure is reduced.
In order to effect this I so design the structure, that on loading it the various
members can be subjected to simple tensile or compressive forces only, so that
the bending actions shall be practically negligible or of known amount and
direction, and I further design the structure so that the separate members of
which it is built can be subjected only to forces either of compression or tension
and that those parts which are intended to be under compression can never be
in tension and those parts which are intended to be in tension can never be in
compression.
In carrying my invention into effect I build the structure of straight or curved
members which may be united to one another by means of pivotal joints or may
form a continuous curve or curves.
In order that the several members of the frame may, when loaded, be subjected
to simple forces acting along their axes, I build the frame in the form of a
polygon of straight members, each capable of resisting compressive forces act-
ing along them, and these members are united to one another at their junctions
by means of pin joints, so that unless otherwise braced they would be free to
move relatively to one another in the plane of the frame.
The support for the wheel axle and the bearing of the axle to which power is
applied are placed wholly within the polygon and supported from the joints in
this polygonal frame by means of tension members while these two supports are
themselves united by means of a tie or ties. By this means I am able, in the
case where power is transmitted from the axle carried on the bearing to the
wheel supported on the centre by a chain belt or band to cause the forces due
to the tension in the chain, belt, or band to be resisted by the tension members
acting on the centre and on the bearing. These tension members transmit the
strain to the joints and give rise to corresponding compressions on the com-
pression members of the frame.
In order to give lateral rigidity to the structure I place two frames side by
side and unite them at the joints by means of struts, while I cross-brace them
by means of tension members radiating from the centres in one frame to the
joints in the other frame.
I may make a modification of this frame by the addition of another centre.
The three centres thus provided are then united by means of ties, while ties
radiate to the joints in the polygonal frame and the compound frame composed
of two such frames placed side by side is as in the previous cases braced by
means of struts at the joints or at intervals along the members and ties radiat-
ing from the centres in one frame to the joints of the other.
I may equivalently form a frame of a continuously curved member capable
of withstanding compression braced by means of tension members radiating
from two centres within the frame. These centres are tied together by means
of ties. One centre forms the support for the axle of the wheel and the other
centre forms the bearing for the axle to which power is applied. The load is
supported from struts which are attached to the compression member by means
of the pivotal joints and braced thereto by ties.
The bearings for the head or hinged joint uniting this rear frame to the front
frame or fork are supported on the compression member so as to transmit the
pressures to a centre within the frame and so distribute them by means of ties
over a considerable length of the compression member.
In order to give lateral rigidity to the structure I form a compound frame
by placing two such frames side by side as before described.
In frames such as I have described composed of a structure built up of mem-
bers united by means of pivotal joints or forming continuous curves and braced
by means of tension members a small variation in the length of one or more
of the members will allow considerable deformation of the structure to take
place. It is therefore necessary to ensure that all the tension members are tight

page_text: when the structure is unloaded, so that when the load is applied it is transmitted
to the members without preliminary deformation of the structure. To ensure
this I subject all the members to initial stress. That is to say I permanently
maintain the tension members in a state of tension and the compression mem-
bers in a state of compression, and I provide means for adjusting the tension
in the tension members in any of the usual ways.
1000
FELL & JAMES,
1, Queen Victoria Street, London, E.C., Agents for the Applicant.
Improvements in Frames for Cycles and similar Machines, Motor
Cars, or Carriages.
I, CLAUDE WILLIAM ATKINSON, of Glendale, Woodland Place, Penarth, in
the County of Glamorgan, 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; -
This invention relates to bicycles, tricycles, and similar machines, and has for
its object the arrangement and construction of those parts of these machines
which form the framing on which the load is carried and supported on the axles
on which the wheels revolve, whereby considerable decrease in weight of these
parts can be obtained without reduction in strength, and also reduction in cost
of manufacture is effected. Structures of this kind are in general built up of
several members which when the structure is loaded are subjected to forces tend-
ing either to stretch, compress, or bend them, and the different members must
be sufficiently strong to resist these forces. The actual magnitude of the forces
is usually comparatively small, when these forces are those of simple tension or
compression, so that were the members of the structure liable to be subjected
to these simple forces only, the cross-section of the material of which they are
composed might be small. In the frames usually built, however, the various
members of the structure are not in general subject to forces of simple tension
or compression only.
On
This arises either from the structure not being so perfectly braced as to
haa
avoid
completely having bending actions on some of the members when the load is
applied or frequently variations in the position of the load or alterations in
external forces due to the actions when in use cause members which have pre-
viously been in tension to become in compression, or vice versa, or to be subject
to bending moments. In addition to this, forces not due to direct loading of
the structure in the usual way may be either accidentally or purposely applied
transversely to some of the members, subjecting them to bending actions.
account of these several reasons it is necessary in the frames usually built to
make the several members of such sizes and shapes as will allow of members
which, under normal conditions, would be subject to tensional forces being put
into compression and will also allow of bending actions being applied to any of
them, and on this account the amount of material required to resist these varia-
tions in direction of the forces or these bending actions is largely in excess of
what would be required to resist simple forces of tension or compression only.
In order to prevent the collapse of the structure when loaded, owing to imper-
fect bracing, the joints between the adjacent members are made rigid either
by means of brazing or riveting, or the like, which is liable to reduce the strength
of the material, or by means of rigid junction-pieces to which the adjacent mem-

page_text: bers are separately and rigidly attached, which causes additional weight of
material to be used. My invention consists in means for overcoming these
difficulties, whereby the amount of material required in the structure is reduced.
In order to effect this, I so design the structure that on loading it the various
members can be subject to simple tensile or compressive forces only or that
the bending actions shall be practically negligible or of known amount and
direction, and I further design the structure so that the separate members of
which it is built can be subjected only to forces either of compression or tension,
and that those parts which are intended to be under compression can never be
in tension and those parts which are intended to be in. tension can never be in
compression.
In order that my invention may be the better understood I will now proceed
to describe the same, reference being had to the accompanying drawings, and
to the letters marked thereon, like letters referring to like parts in the several
figures.
In carrying my invention into effect I build the structure of straight or curved
members, which may be united to one another by means of pivotal joints or
may form a continuous curve or curves.
For clearness I will describe my invention as applied to the construction of
the main or rear frame of a bicycle of the ordinary safety type.
Figures 1, 2, 3, 4, 5 and 6 represent different views of frames made in accord-
ance with my invention. In these figures those members which are constructed
so as to be capable of resisting compressive forces are shown by means of thick
lines, while those which are capable of resisting tensile forces only are denoted
by means of thin lines. Figure 1 is a side view of a frame built of straight
members braced by means of members radiating from centers. Figure 2 is a
plan of two such frames braced together to form one frame. Figure 3 is a side
view of a frame built of straight members braced by means of members radiating
from centers. Figures 4 and 5 are side views of frames each built up of a con-
tinuous curved compression member braced by tension members radiating from
centers. Figure 6 is a plan of two such frames braced together so as to form
one compound frame. Figure 7 is a side view of a compression member accord-
ing to my invention. Figures 8 and 9 are part views of same, showing the
pivoted connection of two such members and the connection of the bracing.
In order that the several members of the frame may when loaded be subjected
to simple forces acting along their axes, I build the frame in the form of a
polygon, as shown in Figures 1 and 2, in which the frame is built up of the
members A B C D E, each capable of resisting compressive forces acting along
them, and these are united to one another at their junctions K' K2 K3 K4, and K
by means of pin-joints, so that unless otherwise braced they would be free to
move relatively to one another in the plane of the frame.
The support L for the wheel-axle and the bearing M are placed wholly within
the polygon K1, K2, K³, K+, and K5 and supported from the joints in this poly-
gonal frame by means of tension members 11, 12, 13, 14, 15 and m¹, m², m³, m
and m, while these two supports are themselves united by means of the tie m6.
By this means I am able in the case where power is transmitted from the axle
carried on the bearing M to the wheel supported on the center L by a chain
belt or band to cause the forces due to the tension in the chain belt or band to
be resisted by the tension members, acting on L, and m², m³, acting on M,
these tension members transmitting the strain to the joints K5 K² and K³, and
giving rise to corresponding compressions on the compression members of the
frame.
In order to give lateral rigidity to the structure, I place two frames side by
side, as shown in Fig. 2, and unite them at the joints by means of the struts K³,
K2, K³, and K+, while I cross-brace them by means of tension members radiating
from the centers L and M in one frame to the joints in the other frame. In
Fig. 2, I have shown some of the ties in one of the frames and some of these

page_text: radiating from the centers to the joints in the other frame; but most of the
tension members are left out for purposes of clearness. In Fig. 3 I show a
further modification of this frame by the addition of the center N. The three
centers L, M, and N are then united by means of the ties n n m³, while ties
radiate to the joints in the polygonal frame, and the compound frame, composed
of two such frames placed side by side, is, as in the previous cases, braced by
means of struts at the joints or at intervals along the members and ties radiating
from the centers in one frame to the joints of the other.
In Figure 4 I show a frame composed of a continuously-curved member C,
capable of withstanding compression, braced by means of tension members n¹
radiating from the center N, m¹ radiating from the center M, and radiating.
from the center L, these centers being tied together by means of the ties n³ n* m".
The center L forms the support for the axle of the wheel, and the center M
forms the bearing for the axle to which power is applied. The load is sup-
ported from the struts S and S', which are attached to the member C by means
of the pivotal joints K¹ K and braced thereto by the ties t, t¹, t2, t.
The bearings for the head or hinged joint uniting the rear frame to the front
frame or fork are supported on the pins passing through the joints K2 and K³
on the struts H and H', which are attached to the member C by the pivotal
joints K and K and tied thereto by the ties and . When the pressures
due to the load carried on the struts S and S¹ and transmitted through the
struts Hand H are large, these would give rise to large forces acting on the
member Cand, owing to its curvature, give rise to considerable bending actions.
on those parts of the member which lie between the ties n¹ m' l. In order to
reduce this, I insert the rigid struts G¹ G3 G3 G (shown in Figs. 4 and 5) to
transmit the pressures to the center N and so distribute them over a greater
length of the member C through the ties n¹.
In order to give lateral rigidity to the structure, I form a compound frame
by placing two such frames side by side, as shown in Fig. 6, and I maintain
them at a fixed distance apart by means of struts attached to the member C at
intervals, and I prevent them from moving relatively to one another by means
of ties radiating from the centers L, M, and N in one of the frames to the mem-
ber C in the cther frame of which the compound frame is composed. It is some-
times convenient to omit the center N, in which case the struts G1, G2, G³,
and G4, if used, will be supported by the center M and the ties n' will be replaced
by similar ties radiating from the center M. and L.
In Fig. 5, I have shown a similar frame to that in Fig. 4 with the exception,
however, that the struts G3 G are left out and the member C is supported by
tension and compression members G5 and G6, radiating from an additional cen-
ter 1, which is similarly supported to the center L.
In frames such as I have described, composed of a structure built up of mem-
bers united by means of pivotal joints or forming continuous curves and braced
by means of tension members, a small variation in the length of one or more
of the members will allow considerable deformation of the structure to take
place. It is therefore necessary to insure that all the tension members are
tight when the structure is unloaded, so that when the load is applied it is
transmitted to the members without preliminary deformation of the structure.
To insure this, I subject all the members to initial stress-that is to say, I
manently maintain the tension members in a state of tension and the compres-
sion members in a state of compression, and I provide means for adjusting the
tension in the tension members in any of the usual ways.
per-
I am aware that polygonal frames have been made having one or more ties
between some of their angles; but these frames have differed entirely from
those now described by me in not having the joints between the members pivotal,
so as to insure the absence of bending actions due to loading of the structure
and in not having the pressures due to loading or propulsion transmitted to the

page_text: frame by means of tension members to avoid bending actions on the compres
sion members.
I am also aware that frames have been constructed having the central part
either circular or elliptic in shape and braced by tension members radiating
from a center; but these frames have had brackets or subsidiary framings to
carry the hinged joint or head, the bearing of the axle to which power is applied,
and the support for the wheel-axle which have been directly attached to this
circular or elliptic frame, so that when the structure has been loaded the central,
circular, or elliptic part of the frame has been heavily stressed locally where
these attachments have been made and considerable bending actions have
resulted, due to the rigid and direct attachment of these brackets. Now by sup-
porting the wheel-axle and the bearing of the axle to which power is applied
within the frame, as I have described, I distribute the large pressures due to
the forces on these parts over a large portion of the curved member, and similar
results are obtained by means of the struts which I have described for trans-
mitting the other pressures to a center within the frame.
In Figs. 7, 8 and 9 I show the construction in detail of a compression member,
which consists of a series of rods or tubes-in this case four in number-which
are maintained in position by being threaded through perforated washers or
distance-pieces s. The ends of the rods are held within a pivotal cap P, which
is adapted to hinge upon the cap at the end of the adjacent compression mem-
ber by means of the pin T¹. The tension member n is formed of a piece of
wire which is wrapped around the pin T¹ and has its ends taken to a center N,
the tension being set up by nuts threaded upon the tension member, so as to
put a tension strain therein.
For the purposes of clearness of illustration in the case of the frames I have
not shown the complete system of bracing by including all the ties in the
figures; but it will be clear from the description how the complete bracing is
effected, which include the ties not shown in the figures.
I have only shown one means for initially stressing the frame, as described,
or subsequently adjusting its form or the amount of stress; but it is obvious
that any of the well known methods may be employed for varying the length
either of the compression or tension members to produce the desired result.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1st. A frame for a cycle, comprising the compression members, supports for
the crank-axle and back-wheel axle, both located within the space enclosed by
the compression members, tension members extending from said supports to
various parts of the compression members, and tension members extending
between the said supports, substantially as described.
2nd. The arrangement and construction of frames for cycles, motor cars and
the like, substantially as described and illustrated in and by the accompanying
drawings.
3rd. A frame for a cycle, motor car and the like comprising compression
members connected by pivotal joints, supports for the crank axle and back
wheel axle, both located within the space enclosed by the compression members,
tension members extending from said supports to the various joints of the com-
pression members and tension members extending between the said supports,
substantially as described.
4th. A frame for a cycle, motor car, and the like, having a compression mem-
ber having a continuous curve, supports for the crank axle, both located within
the space enclosed by the curved compression member, tension members extend-
ing from the said supports to various parts of the curved compression member,
compression members from the curved compression member to the said sup-

page_text: ports to transmit the external forces thereto and tension members extending
between the said supports, substantially as described.
5th. In a frame for a cycle, motor car and the like, in combination, a circum-
scribing compression member or series of compression members pivotted together,
supports for receiving the dead load and motive force, located within the space
enclosed by the compression member or members, tension members extending
from said supports to various parts of the compression member or members,
and tension members extending between the said supports, substantially as
described.
Datal 4 101
1000
FELL & JAMES,
1, Queen Victoria Street, London, E.C., Agents for the Applicant.