Improvemen s in or relating to Adjustable Frames for Cycles and the like.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvemen s in or relating to Adjustable Frames for Cycles and
the like.
I, FITZ-HARDINGE ROBERT BAYFIELD LIEBENROOD, of Red House, Halfway Street,
Sidcup, in the County of Kent, Barrister-at-law, do hereby declare the nature of this
invention to be as follows:-
This invention relates to adjustable frames, chiefly for cycles, and may be carried
out in the following manner:-
The object which I have in view is to make the frame, say for example of a
safety bicycle, adjustable in such a manner that the top tube which extends from
the steering-head to the junction with the back stays where the saddle pin is carried,
can be adjustable at its back end to different heights of the saddle support or L pin
so that this tube which I will call the horizontal tube, though the plane in which it
lies actually varies, always terminates substantially immediately underneath the
saddle, the seat pillar forming as it were an extension of the back portion of the
frame, and being thus included in the frame itself instead of being as at present
outside the frame. The forward end of the stay may be raised or lowered if desired,
but it is not always necessary that it should be so.
Practically I connect one end of this horizontal stay to the steering-head or lug.
and carry it back to the seat pillar to which it may be joined by any suitable form of
joint or connection. If desired I may form a lug upon the seat pillar itself and let
the back end of the horizontal stay be caught in that lug. Or I may have a lug
upon the stay which would clip the seat pillar, means being provided to
accommodate the varying angles between the stay and seat pillar according to
whether the latter was far out of the frame or far into it. The seat pillar would
be fixed at its lower end to the frame by a divided lug or the like as usual.
The stay itself is divided into two parts in order that its length may be varied
according to the position in which it is placed, as it will be shorter when
the seat pillar is close in to the frame than it will be when the seat pillar
is drawn a suitable distance out of the frame and also so as to regulate the
tension. I connect the two divided portions of the stay by means of a sleeve screwed
internally and I screw the end of each piece of the stay, but I make the pitch of one
quicker than that of the other, the respective ends of the nut being correspondingly
"hand
screwed. By this means although both screws are of the same
it will be
seen that since the pitch of one is quicker than that of the other merely turning
the nut in one direction will draw the two parts together, or in the opposite direction
will move them apart, so that I can readily adjust this stay as required.
Instead of this differential screw I may accomplish the same result but in a less
advantageous way by the use of right and left-handed screws.
One or more lock nuts may be employed if desired to secure the sleeve when
adjusted though in ordinary work I do not find this necessary.
In making a bicycle according to this invention I prefer to have the stay at the
front end at a height suitable for a medium sized machine, but to make the frame at

page_text: the back of the smallest sized machine, so that according to the height at which it
is required to place the saddle the Horizontal stay tube may be lower at its back
end or level, or higher, thus equalizing the deviations from the horizontal as inuch
as possible, the saddle being always substantially close down to the stay.
Where it is desired to utilize this invention in adapting the machine as either a
closed or open-fronted one I provide suitable-joints or equivalent so that this
horizontal tube may be dropped to a diagonal position being pivotted at the front
end, the back end being clamped on to one of the back diagonals or to the crank axle
bracket in any convenient manner, and then screwed up by. means of the sleeve
already described.
Generally I prefer to divide the stay at about the centre but it will be appreciated
that the same result can be obtained by placing the adjusting portion at one end.
I prefer to use this screw adjustment in the top horizontal tube but I may
alternatively use it in the diagonals of the frame to accomplish a similar result.
•
In all cases the sleeve or nut which draws the two parts together may be placed
inside the tubes instead of outside.
Dated this 12th day of January 1897
Improvements in or relating to Adjustable Frames for Cycles, and
the like.
I, FITZ-HARDINGE ROBERT BAYFIELD LIEBENROOD, of Red House, Halfway Street,
Sidcup, in the County of Kent, Barrister-at-law, 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 adjustable frames, chiefly for cycles, its object being to
make a frame, of for instance a safety bicycle adjustable with the aid of a. stay or
member of variable length, so as to alter the height of the frame to suit any rider
and still have the saddle-pillar included as an effective portion of the frame; or to
convert a diamond frame into a drop frame suitable for a lady. This stay comprises a
differential adjusting device, and is so constructed that the distance between its ends
or parts is susceptible of ready variation to enable it to connect portions of the frame
separated by different distances. As a final variation of the length of the stay to
tighten it has to be effected by the differential action of the aforesaid adjusting-
device, subsequent to the establishment of such connection, the stay is so made
that this tightening action cannot exceed a pre-determined maximum, which is
intentionally limited in order to render impossible any improper stressing of the stay
or of the frame to which it is applied.
Further the top frame-member which ordinarily extends from the steering-head
to a junction with the back-stays where the seat pillar is carried, is according to this
invention adapted, to engage instead with the seat pillar and if. necessary made
telescopic or extensible in any convenient manner for that purpose.
..It will move to different heights with the seat pillar, according as the latter is
shifted endwise, but it will always terminate. substantially immediately beneath the
saddle, though its inclination in the vertical plane will vary; the top frame-member
thus employed preferably has a differential adjusting-device for varying its length,
although if desired it may simply be divided between its ends and have the two parts
coupled by a simple screw-coupling, or it may be otherwise constructed. The 'seat
pillar, when the top tube or frame member is thus connected to it, forms in effect an

page_text: element of the frame, being included in the frame itself instead of being as at present
outside it.
Further, where it is desired to utilise this invention in adapting the machine as
either a closed or open-fronted one, suitable joints are provided so that the top tube
may be dropped into a diagonal position for this purpose it is pivotted at the front
end, the back end being arranged to clamp on to the down tube at, or at any desired
height above, the bottom bracket, by means of a strong adjustable lug. The stay,
after being so fixed, is tightened up by means of the aforesaid differential adjusting-
device hereafter more particularly referred to.
In the accompanying drawings
Figure 1 is a side-elevation, partly in section, of an adjustable cycle-frame, according
to this invention; the seat-pillar and differentially-adjustable top tube in this view
are elevated to about the highest limit of their adjustment. The upper and lower
chain-lines A¹ F2 and A¹ F3 show respectively the mean and lower limits of the
adjustment of the top tube.
Figure 2, a similar view, shows the saddle and top tube lowered to the lower limit
of their adjustment in company.
66
Figure 3, also a side elevation, shows the same frame with the top tube adjusted in
the manner hereinafter explained so that the frame becomes a drop" frame; an
alternative position of the top tube, obtainable by shifting the adjustable lug B¹ up
the down-tube B is shown in this Figure in dotted lines.
Figures 4 and 5 are longitudinal central sections of the stay or frame member,
comprising a differential adjusting-device and included in Figures 1 and 2, in which
it is drawn upon a smaller. scale. In Figure 4 the extensible stay is shown with its
ends adjusted to approximately their minimum distance apart, prior to the final
tightening of the stay by differential action; in Figure 5 the stay is shown with its
ends adjusted to approximately their maximum distance apart, before the stay is
finally tightened.
Like letters indicate like parts throughout the drawings.
A is the head tube, B the down tube, C the bottom tube, D the back stay, and E
the bottom stay of the frame, which, as far as these parts are concerned, is like an
ordinary diamond frame, except that near the bottom of the down tube B there may
be a lug B¹ for the purpose hereinafter explained; preferably this lug is adjustable
along the down tube B. F is the seat-pillar adjustable endwise in the down tube B
in a manner well understood, and capable of being locked in position therein by the
usual means, such for example, as a divided middle frame-lug B².
The top frame-member shown in the drawings is constituted by two parts G, G¹
and a connection such as the sleeve H which internally is differentially-screw-
threaded, the end H2 of the connection being threaded to fit the adjacent threaded
portion G2 of one end of the stay, and the end H³ being threaded to fit the threaded
portion G3 of the opposite end of the stay. These threads it is found preferable to
cut in the bore of steel sockets H H about an inch in length which after being
threaded are brazed or sweated into the sleeve H at such distances apart as to give the
stay the maximum extensibility desired.
In order to reduce to a minimum the space between the adjacent ends of the
portions G2 G3 of the stay when it is being used at about its minimum length, as
shown in Figure 2, the diameter of the threaded portion G³ can be made less than
that of the portion G2 so that just before the stay is tightened, the inner end of the
portion G³ may extend through the socket H* into close proximity to the end of the
portion G². The ends when the stay is tightened up will come almost into contact
with each other. The pitch of the thread on one of the two parts G G¹ is less than
that on the other, both threads being of the same "hand," that is to say both right-
handed or both left-handed. Since the pitch of one thread is different from that of
the other, rotation of the sleeve H in one direction about the axis of the stay will
(assuming that the parts G G¹ are so secured at the ends as not to be rotatable about
their axis) draw the two ends together differentially so that only the predetermined
maxim strain, and consequently only the pre-determined maximum stress, can be put

page_text: .
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66
upon the frame by the stay. Rotation of the sleeve in the opposite direction will
reduce that stress which will altogether disappear so soon as the parts G2 and H2
become disengaged. The distance between the ends or parts G G₁ of the stay is
susceptible of variation after such disengagement, as the two sections are then merely
telescopic," so that the part H can slide over the screw-threaded part G2 and there-
fore the ends G G of the stay can be drawn apart as required to adapt it to its new
position and when the saddle pillar is again secured the sleeve H is again screwed off
the part G on to the part G2 as far as it can go, when the pre-determined
maximum stress will again be exerted during the period in which the sleeve H is
screwed over the part G2. The tightening nut or clamp if such be employed is then
screwed up and the stay made rigid.
It will be evident from the foregoing that if after the opposite ends of the stay are
coupled up to each other and to the frame, the sleeve H is rotated, any shortening
of the stay which may take place can only occur by reason of differential action. In
order to render it impossible that any improper stressing of the stay or of the frame
should be induced by such action, the movement of the connection must be limited
to a pre-determined extent; such limitation in the example illustrated is obtained
by the shoulder G4 on the part G, coming home against the nut or screwed portion
• H² of the sleeve H so that differential alteration in the length of the stay is limited
to that which can occur during the movement of the end H2 of the connection H
along the screw-threaded portion G. Thus if there are twelve complete turns of
the thread on the part G2, the connection H cannnot make more than twelve turns
in being screwed on to that part, and consequently will only make twelve turns upon
the screw-threaded portion G³ of the other end of the stay, and assuming for example
that the pitch of the screw-thread on the latter is such that those twelve turns
extend over a shorter axial length of the stay than the twelve turns on the
part G, the amount by which it is possible to tighten or strain the stay under
these conditions would be represented by the difference between the two axial
lengths referred to. This difference being fixed and determined by the proportions
given to the parts in their manufacture cannot be varied by the user of the device,
who is unable to put any more stress upon the machine or stay in tightening the
latter than is producible by the maximum extension predetermined and limited as
stated. This makes the strain constant and uniform at all the varying distances
apart at which the ends of the stay may be used.
In the example illustrated the coarser thread is on the portion G2 of the stay and
the finer thread on the portion G³, so that the stress resulting from screwing the
sleeve H home upon the part G2 is a tensile one. If it be desired to cause the device
to exert, by similarly screwing up the sleeve H along the threaded portion G2, an
action which would increase instead of diminish the distance between the ends of the
stay, it is only necessary to reverse the arrangement of the screw threads by putting
the finer pitched thread on the portion G2 and the coarser thread on the
portion G³.
By selecting a suitable ratio for the pitches of the two threads the device may be
constructed to produce any desired stress in the frame, the action of the stay being
constant, although its total length is variable within wide limits.
In the example illustrated in the drawings of the application of this differential
stay or frame-member, its end G is connected as at A¹ to a strong lug on the head
tube A, the opposite end G¹ being connected to a lug F1 securely fixed upon the seat
pillar F as near as possible to the saddle. Preferably the joints between this
differential frame-member and the head tube A and seat pillar F should be pin-
'connected as shown, as that frame-member has to make varying angles with these
parts in its adjustment with the seat pillar as indicated by the chain lines A¹ F² and
A F3; but instead of pin-connected joints any other construction may be adopted
which will permit of the desired up and down movement of the stay with the seat
pillar. If desired the head tube A can be made to extend up from the tube C
further than is usual so as to reduce the upward inclination at which (as shown in
Figure 1) the stay proceeds from the head tube towards the saddle.

page_text: To change the diamond frame illustrated in Figure 1 into the drop frame shown
in Figure the sleeve H is.disengaged from the portion G of the stay; the pin
connecting the differential frame-member with the lug F1 is removed and the stay
turned downward about its hinge in the lug A¹. The part G¹ can then be drawn
away from the portion G to meet and be secured to the adjustable lug B¹. When
the stay is thus secured the sleeve H is again screwed off the part G¹ into
engagement with and home upon the portion G of the stay until arrested by the
shoulder G, when the predetermined maximum strain of the stay will have been
obtained;
the sleeve can then be locked, say by the clamp G5 hereinafter
The adjustment of the lug B' along the down tube enables a single machine to be
made to suit various riders; for example a beginner or a lady rider of light weight
would prefer to have the lug as near to the bottom bracket as safety would allow,
whereas for heavier riders the lug B¹ could be raised into some such position as that
in which it is indicated by dotted lines, to enable the stay G H G¹ to impart greater
strength and rigidity to the frame.
referred to.
The ends of the sleeve H are preferably unthreaded and extended sufficiently far to
conceal and protect the threads on the parts G G¹. If required one or more lock
nuts or locking devices may be employed to secure the sleeve H after adjustment;
if used they should preferably be placed on the rear end of the sleeve H which might
for instance be formed with a clainp G5. Instead of an internally-threaded sleeve H
engaging external threads on the parts G G¹ they may be provided with internal
differentially threaded portions connected and adjustable by a screwed rod received
within them, and accessible at a gap left between them, but the before described
method will be found to be very convenient and practicable.
It is to be clearly understood that the differential stay or frame-member hereinbefore
described is not intended only for employment in cycle frames, nor need it be used
in cycle frames in the particular situation in which it is indicated in the drawings by
way of example.
Having now particularly 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
1. In a cycle frame or the like a top tube to rise and fall with the seat support, so
that the latter shall be effective as a portion of the frame.
2. In a cycle frame or the like a top tube provided with a differential or other
screw adjusting device, and so arranged to rise and fall with the seat support that
the latter shall be effective as a portion of the frame.
3. In a cycle frame or the like a top tube capable of being lengthened and
shortened, provided with a differential or other screw-adjusting device, and arranged
so that without disconnecting either of its ends from the machine, it can rise and
fall with the seat support to enable the latter to be effective as a portion of the
frame.
4. A stay or frame-member of variable length comprising a differential adjusting
device, and so constructed that the variation of its length by differential action is
5 limited.
5. In a stay or frame-member of variable length, the combination with differentially-
threaded portions such as G G¹, of a differentially-threaded connection such as H,
which has its movement limited for the purpose described.
6. A stay or frame-member of variable length comprising a differential adjusting-
O device, substantially as and for the purpose described and illustrated in Figures 4
and 5 of the accompanying drawings.
5
7. In a cycle frame or the like a frame-member such as G H G¹ constructed,
arranged, and operating substantially as and for the purpose described and illustrated
in Figures 1, 2, 3 and 4 of the accompanying drawings.
8. A cycle frame which comprises a stay or frame-member of variable length and

page_text: is adaptable in the manner described with reference to Figure 3 of the accompanying
drawings and is also constructed to utilise the seat pillar as an effective portion of
the frame.
Dated this 9th day of November 1905
FITZ-HARDINGE LIEBENROOD.
Boult & Wade,
Agents for the Applicant.