Improvements in Trestles.
Year: 1891

page_text: Date of Application, 30th Oct., 1891
Complete Specification Left, 2nd Aug., 1892-Accepted, 24th Sept., 1892
PROVISIONAL SPECIFICATION.
Improvements in Trestles.
1. ROBERT HENDERSON, of 64, Mount Grove Road, Highbury, in the County
of London, Master Baker, do hereby declare the nature of this invention to be as
follows:-
This invention relates to improvements in trestles chiefly of that class used for
temporary tables.
Hitherto such trestles have generally been constructed of two parts hinged
together at the upper end and, when opened out, the said parts diverge from one
another and have to be connected together near their lower ends by ropes, chains
or bars. When a number of such trestles are required, for the purpose of supporting
temporary tables, considerable time and labour are frequently required to adjust
them to the same height and, in order to secure firmness, pins or bolts are used to
keep the trestles into the position to which they have been opened.
The object of my invention is to provide a trestle which on being fully opened
out will automatically lock itself in its open position so that, where a number of
trestles of the same size are employed, they will all stand on the same level and be
very firm.
In carrying out my invention 1 form my trestle in two parts, one part, hereinafter
called the leg, being. hinged to the other part or trestle proper, so that it will open
out at right angles thereto, similarly to the leg usually employed for supporting
the flap of a table. In the top of the horizontal bar or rail of the trestle I make a
groove with an inclined bottom on which I fix a plate having a channel therein for
the purpose hereinafter described. On each side of the groove I fix a plate which
does not extend to the bottom, that is to say, a space is left between the lower
edges of the said plates and the bottom plate forming a kind of slot on each side of
the groove. At the inner end of the inclined groove is a hole which corresponds
in-depth with the .depth of the deepest part of the groove. Over the top of the
groove:1 place a slotted plate. To the leg of the trestle I fix one end of a metal
bar, the other end of the bar carrying a headed pin, which pin works in the slot in
the top plate, the head working against the channelled bottom plate and in the
slots in the. bottom of the groove.
By this-arrangement, when the trestle is closed, the said pin will be in the
deepest part of the groove in the bar of the trestle but, when the trestle is required
for use and the leg is opened out, the bar carrying the pin will move with the leg,
the said pin moving, in the slot in the top plate and against the channelled bottom
plate, until it comes over the hole in the inner end of the groove, when it will drop
into the said hole.and.automatically lock the leg in its opened position. To close
the trestle it is merely necessary to raise the bar so as to lift the pin out of the said
hole: and the closing of the leg will carry the pin down the inclined plane into its
first position..
In practice I find it advantageous to make my automatic locking trestles right
and left handed, so that two trestles may be folded together when closed for
convenience of transport and storage.
1001

page_text: COMPLETE SPECIFICATION.
Improvements in Trestles.
I, ROBERT HENDERSON, of 64, Mount Grove Road, Highbury, in the County
of London, Master Baker, 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 improvements in trestles chiefly of that class used for
temporary tables.
Hitherto such trestles have generally been constructed of two parts hinged
together at the upper end and, when opened out the said parts diverge from one
another and have to be connected together near their lower ends by ropes, chains
or bars. When a number of such trestles are required, for the purpose of supporting
temporary tables, considerable time and labour are frequently required to adjust
them to the same height and, in order to secure firmness, pins or bolts are used to
keep the trestles into the position to which they have been opened.
The object of my invention is to provide a trestle which on being fully opened
out will automatically lock itself in its open position so that, where a number of
trestles of the same size are employed, they will all stand on the same level and be
very firm.
To enable my invention to be fully understood I will describe the same by
reference to the accompanying drawings in which
Figure 1 is an elevation of a trestle constructed according to the invention.
Figure 2 is a plan of the same shewing the parts of the trestle in their open
position for use and
Figure 3 is a similar view shewing the parts in their closed position.
Figure 4 is an elevation of the trestle at right angles to Figure 1.
Figures 5, 6 and 7 are. sections respectively on the lines 5, 5, 6, 6, 7, 7,
Figure 2, and
Figure 8 is a section on the line 8, 8.
Similar letters in all the figures represent similar parts.
In carrying out my invention I form my trestle in two parts, one part a, herein-
after called the leg, being jointed to the other part bor trestle proper, so that it will
open out at right angles thereto (as shewn in Figures 1, 2 and 4), similarly to the
leg usually employed for supporting the flap of a table. In the top c of the
horizontal bar or rail of the part 6 1 make a groove d with an inclined bottom on
which I fix a plate e having a channel therein for the purpose hereinafter
described. On each side of the groove is a plate g which does not extend to the
bottom, that is to say, a space is left between the lower edges of the said plates g
and the bottom plate e forming a slot h on each side of the groove. At the inner
end of the inclined groove is a hole i which corresponds in depth with the depth of
the deepest part of the groove. Over the top of the groove I place a slotted
plate which in the drawing is shewn formed in one with the plates g, g, but they
may be made separate. To the leg a of the trestle I fix one end of a metal barj
the other end of the bar carrying a headed pin k, which pin works in the slot in the
top plate l, the head working against the channelled bottom plate e and in the slots h
in the bottom of the groove.
By this arrangement, when the trestle is closed, as in Figure 3, the said pin k will
be in the deepest part of the groove in the bar of the trestle but when the trestle
is required for use and the leg is opened out, as shewn in Figures 1, 2 and 4, the
bar carrying the pink will move with the leg a, the said pin moving in the slot
in the top plate and against the chaunelled bottom plate, until it comes over the
hole in the inner end of the groove, when it will drop into the said hole and
automatically lock the leg in its opened position. To close the trestle it is
merely necessary to raise the bar so as to lift the pin out of the said hole

page_text: and the closing of the leg will carry the pin down the inclined plane into its
first position.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
(1.) A trestle having the two parts thereof connected together by a joint
constructed, arranged and operating substantially in the manner and for the purpose
hereinbefore described.
(2.) The manufacture and use of the improved trestle hereinbefore described
and illustrated in the accompanying drawings.
Dated the 2nd day of August 1892.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.