IMPROVEMENTS IN BICYCLES AND OTHER VELOCIPEDES.”
Year: 1881

page_text: LETTERS PATENT to Gerard Strickland, of No. 217, Strada San Paolo
Valletta, Malta, for an Invention of "IMPROVEMENTS IN BICYCLES AND
OTHER VELOCIPEDES.”
PROVISIONAL SPECIFICATION left by the said Gerard Strickland at the
Office of the Commissioners of Patents on the 6th August 1881.
GERARD STRICKLAND, of No. 217, Strada San Paolo, Valletta, Malta. "IMPROVE-
MENTS IN BICYCLES AND OTHER VELOCIPEDES."
In the use of bicycles it is practically found of advantage to have means of
adjusting the rake or inclination from the vertical of the fork which carries the
axle of the driving wheel so as to allow for acclivities and declivities of the road.
My Invention relates to means of varying the rake of the fork without the
necessity for dismounting. For this purpose I divide into two parts the bent tube
which forms the back bone of the bicycle fitting those parts to slide the one
within the other, so that the length measured along the backbone between the
axis of the driving wheel fork and the centre of the hind wheel can be mado
greater or less by sliding outwards or inwards the two parts of the backbone.
The variation of this length may be effected in various ways. According to one
arrangement I attach to one part of the divided backbone a piston working in a
cylindrical portion of the other part, and I provide a small pump worked by a
handle like that used for the brake, whereby I can force oil or other suitable
liquid so as to act against this piston and cause it to move in the one direction or
the other. According to another arrangement I form a hollow flexible screw by
twisting a strong wire like a helical spring, and I introduce this into the interior
of the backbone tube, its flexibility allowing it to be turned therein. I connect
this screw by universal joints and suitable gearing to the steering handle, so that
by turning the steering handle I can cause the screw to revolve in the one direction
or the other. From the lower part of the divided backbone I extend upwards a
bar passing through adjustable guides in the tube of the back bone, and through
Dine 621

page_text: the interior of the screw and having on it studs which engage between the
convolutions of the screw. On turning the screw by means of the handle as
aforesaid the lower part of the backbone may be caused to ascend or descend as
desired.
According to another arrangement, I joint the fork of the hind wheel to the
lower end of the back bone and fix on it a toothed worm segment in which
engages a worm which can be turned in the one direction or the other by a chain
pulley and chain led along guides to the steering handle. The fork of the hind
wheel can thus be tilted to a more or less inclined attitude, so as to lower or raise
the backbone relatively to the ground and thereby vary as desired the rake of
the fork of the driving wheel.
Obviously the arrangements above described are applicable to velocipedes other
than those known as bicycles.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said. Gerard Strickland in the Great Seal Patent Office on the
3rd February 1882.
GERARD STRICKLAND, of No. 217, Strada San Paolo, Valletta, Malta. "IMPROVE-
MENTS IN BICYCLES AND OTHER VELOCIPEDES."
In the use of bicycles it is practically found of advantage to have means of
adjusting the rake or inclination from the vertical of the fork which carries the
axle of the driving wheel so as to allow for acclivities and declivities of the road.
My Invention relates to means of varying the rake of the fork without the
necessity for dismounting. For this purpose I divide into two parts the bent tube
which forms the back bone of the bicycle fitting those parts to slide the one
within the other, so that the length measured along the backbone between the
axis of the driving wheel fork and the centre of the hind wheel can be made
greater or less by sliding outwards or inwards the two parts of the backbone.
The variation of this length may be effected in various ways.
According to one method I construct the back bone as shewn in Fig. 1 of the
accompanying Drawing. I make it in two parts, the upper part A as usual a
bent tube circular in section, and the lower part B, which terminates in a fork for
the hind wheel, I make of a section such that it can slide longitudinally through a
bush or bearing C at the lower end of A without turning round therein. A
convenient form is shewn to an enlarged scale by the transverse section, Fig. 2,
where the tube B is of triangular section sliding through cheeks fixed within the
tube A. One of those cheeks may be made adjustable by a setting screw D with
lock nut so as to take up the slack resulting from wear. To the upper part of B
is attached a bent rod E which at its upper end has a collar F in which is cut a
screw thread. With this thread is engaged a helical spring G terminating in a
spindle H which can turn freely in a stationary bush or bearing K, but is
prevented from moving longitudinally by collars on each side of the bearing. To
the spindle H is attached a flexible spindle or shaft L, which is a helical spring
and which can be turned by a winch handle M situated conveniently beside the
steering handle. When the rider wishes to vary the rake of the fork of the front
wheel, he has only to turn in the one direction or the other the bandle M, this
turning the flexible spindle L and the spindle K, causes the spring G also to turn,
and this operates as a flexible screw, causing the collar F, the rod Ĕ, and the lower
part B of the backbone to move upwards or downwards according to the direction
of revolution, and thus lengthening or shortening the backbone.
Instead of making the backbone in two parts, the one-sliding within the other,
the rake of the front wheel fork may be varied by varying the rake of the hind
wheel fork, as shewn in Fig. 3. In this case the hind wheel fork N is jointed to
the lower end of the backbone A, and has an arm connected by a spring O to a
joint P at some distance up the backbone. From an arm constituting an extension
of the spring O, a link entering a slot in the back of the backbone has a pin
which is engaged in inclined slots in a piece Q which can be made to slide within
the backbone by means of a screw R swivelled to Q and working in a stationary
nut S. The screw R is worked by a flexible spindle T, consisting as shewn of
pieces of rod connected to each other by pieces of helical spring, this flexible
spindle being turned by a winch handle at its upper end, as described with
reference so Fig 1. According as the spindle T and screw R are turned in the one
direction or the other, the sliding piece Q is caused to ascend or descend, and its
inclined slots cause the spring O to change its attitude and so to vary the angle
which the fork N makes with the backbone. It is obvious that by bringing the

page_text: fork N towards a vertical attitude the effect is equivalent to a lengthening of the
backbone and conversely, so that the fork of the front wheel can thus be made to
rake more or less forward or backwards, as may be desired.
Having thus described the nature of my Invention and in what manner the
same is to be performed, I claim as means of adjusting the rake of the front wheel
fork of a bicycle or velocipede,-
First. The construction and arrangement, substantially as described with
reference to Figs. 1 and 2, according to which the backbone is made in two parts,
and the lower part is caused to slide longitudinally in the upper part by turning a
flexible spindle and screw accommodated within the backbone.
Second. The construction and arrangement, substantially as described with
reference to Fig. 3, according to which the hind wheel fork being jointed to the
backbone is moved towards or from a vertical attitude by the action of inclined
slots in a slide moved by a screw, turned by a flexible spindle within the
backbone.
.
In witness whereof, I, the said Gerard Strickland, have hereunto set my
hand and seal, this First day of February, in the year of our Lord One
thousand eight hundred and eighty two.