IMPROVE- MENTS IN BOOK SLIDES OR HOLDERS
Year: 1863

page_text: PROVISIONAL SPECIFICATION left by Frederick Henry Twilley at tho
Office of the Commissioners of Patents, with his Petition, on the 26th
February 1863.
I, FREDERICK HENRY TWILLEY, of Dean Street, Soho, in the County of
Middlesex, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN BOOK SLIDES OR HOLDERS," to be as follows:-
This Invention consists of certain improvements in the construction of slides
or holders for books, whether single or double slides, whereby they may be
extended in width in order to hold a considerable number of books, or bo
reduced so as to contain a few books only, dispensing entirely with all cross
pieces, as have heretofore been used.
I propose to form the single slides or holders as follows:-I take a slab of
wood of the requisite size, and on the upper surface thereof, on each side,
I affix a narrow slip, the two interior sides of which are grooved or rebated in
order to allow a tongued slide to move therein, and be kept in position; the
outer end of this tongued slide is provided with a flap or side support hinged
thereto, which may be shut down when not in use, or be raised to a vertical
position in order to support the books placed on the holder; the other end of
the slab is also provided with a similar hinged flap. By these arrangements it
is obvious that the moveable slide may be drawn out or extended to nearly
double the length of the slab, or it may be contracted so as to leave a very
small space between the two flaps, according to the number of books to bo
held. I provide a rack on the surface of the slab between the grooved slips,

page_text: and fix a small catch or pall to the lower surface of the tongued slide, in order
that when the flap is drawn out or pushed in, its position may be maintained
against the pressure of the books.
With regard to double slides or holders, I propose to place the fixed hinged
flap in the centre of the slab, and to form two moveable slide flaps, one on
each side thereof; these slides should be formed so as to run into each other,
and so enable the flaps to be drawn close up to the fixed central flap. This
is accomplished by forming one slide as a tongue running between a slot or
livision of the other slide. The rack, and catch, or pall may also be adopted
in this example to each slide.
A modification of the principle of these holders may consist of a single
holler with both flaps moveable, in which case the sliding pieces should be of
half the length of the slab, and meet in the centre thereof; they should be
formed one as a tongue, and the other as a channelled slide, in order to run
one within the other. By this means the flaps may be both brought to the
centre or other part of the slab, and hold the books securely by the aid of the rack,
and catch, or pall. A small button or projection attached to the catch or pall
serves to disengage the same from the rack by pressure from the hand, in order
to move the slides to their requisite position on the slab.
In some cases I propose to employ metallic springs in order to maintain the
side supports in close proximity to the hooks within the slides; these springs
are to work either by tension or compression; for instance, by attaching one
end of a straight piece of clock spring to the slide and the other end to the
slab, and then compressing the two ends of the spring by drawing out the
slide, the spring, when released, will inevitably force the slide back; so also if
the spring is of a semicircular form, by endeavouring to straighten it by the
same means, its tendency will always be to resume its position, and thus draw
back the slide after the removal of any book. Or a helical clock spring, or
blind roller spring may be used with equal advantage.