An Improved Gear for Opening and Closing Greenhouse Lights.
Year: 1892

page_text: Date of Application, 28th Apr., 1892
Complete Specification Left, 28th Jan., 1893—Accepted, 18th Mar., 1893
PROVISIONAL SPECIFICATION.
An Improved Gear for Opening and Closing Greenhouse Lights.
I, EDGAR NEWTON of Hitchin in the County of Herts, Horticultural Builder,
do hereby declare the nature of this invention to be as follows :-
This invention relates to means for operating the lights of greenhouses in a ready
and convenient manner. The lights of greenhouses are frequently arranged in series,
and lifted and closed all at once by the partial rotation of a shaft running the
length of the house.
The rotation of this shaft, which is generally gaspipe, with the levers connecting
with the lights secured thereon by set screws, is a matter of difficulty, owing
to the weight of the lights, and the desirability of fixing them open at any point.
According to my invention, I provide a powerful gear for operating the lights,
which can be worked with a very slight expenditure of strength, and which will
not run back and allow the lights to fall when released by the hand.
The gear embodying my invention includes the ordinary links hinged to the
lights and to the levers secured on the rotating shaft. A very efficient means of
fixing these levers to the rotating shaft is provided by destroying the circularity
of the cross section of the latter, and threading thereon the levers furnished with
eyes or sockets of corresponding form, so that there is no possibility of the levers
turning on the shaft.
The rotary movement of the shaft is effected by a threaded bar attached at one
end to a link rod pivotted to the end of a crank arm or lever fixed on the shaft,
and at the opposite end passing loosely through a fixed bearing to a nut threaded
to correspond with the threads in the bar.
The nut is made, externally, in the form of a pulley, which can be rotated by
an endless belt or chain in either direction. The fixed bearing through which the
threaded bar loosely passes, is carried upon a bracket pendent from one of the
rafters of the greenhouse roof, the said bracket being strengthened by a stay also
secured to the rafter.
The opening of the lights is effected by turning the pulley, which is held con-
stantly against the fixed bracket, by the weight of the lights pulling on the
threaded bar. The rotation of the pulley one way draws the bar through the fixed
bearing, so as to rock the rotating rod and open the lights, while the rotation of the
pulley in a reverse direction permits the threaded bar to recede, and the lights to
close by their own weight.
A metal ring or washer is preferably employed between the pulley and the
bracket, to ensure as nearly as possible an even bearing for the pulley to work
against; likewise the bearing in the bracket is provided internally with a collar
flared out so as to give room for the threaded bar to work to and fro, even when
pulled somewhat out of line by the arm on the rotating shaft.
With the gear above described, the lights can be operated with ease and accuracy,
and will only move under the influence of the pulley when the latter is intentionally
worked. The chain or band for working the pulley can hang down, or be looped
up anywhere without being tied, as the pulley will have no tendency to run back
when not held.
Dated this 28th day of Anril 1892.

page_text: COMPLETE SPECIFICATION.
An Improved Gear for Opening and Closing Greenhouse Lights.
I EDGAR NEWTON of Hitchin in the County of Herts, Horticultural Builder,
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 means for operating the lights of greenhouses in a
ready and convenient manner. The lights of greenhouses are frequently arranged
in series, and lifted and closed all at once by the partial rotation of a shaft running
the length of the house.
"
The rotation of this shaft, which is generally gas pipe, with the levers con-
necting with the lights secured thereon by set screws, is a matter of difficulty,
owing to the weight of the lights and the desirability of fixing them open at any
point.
According to my invention, I provide a powerful gear for operating the lights,
which can be worked with a very slight expenditure of strength, and which will
not run back and allow the lights to fall, when released by the hand.
My invention, as applied to the lights of a greenhouse roof, is illustrated ip
the accompanying drawings.
Fig. 1 is a cross section through the ridge, shewing two sets of gear, one set for
operating the series of lights on each side of the ridge.
Fig. 2 is a similar view, illustrating a modification by means of which the lights
on both sides are operated by one gear.
Fig. 3 is a detached plan of the gear illustrated at Fig. 2.
The gear embodying my invention includes the ordinary links a, hinged to the
lights A and to the levers b, secured on the rotating shaft B. A very efficient
means of fixing these levers to the rotating shaft, may be provided by destroying
the circularity of the cross section of the latter, and stringing thereon the levers
furnished with eyes or sockets of corresponding form, so that there is no possibility
of the levers turning on the shaft. In the drawings, however, the shafts B are
shewn circular in cross section.
The rotary movement of the shaft is effected by a threaded bar C, attached
at one end to a link rod d, pivotted to the end of a crank arm or lever D, fixed
on the shaft B, and, at the opposite end, passing loosely through a fixed bearing,
to a nut F, threaded to correspond with the threads in the bar C.
The nut F is made externally in the form of a pulley which can be rotated
by an endless belt or chain'in either direction. The fixed bearing e through which
the threaded bar loosely passes, is carried upon a bracket E, pendent from one of
the rafters of the greenhouse roof, the said bracket being strengthened by a stay e³,
also secured to the rafter.
The opening of the lights is effected by turning the pulley F, which is held
constantly against the fixed bracket. E by the weight of the lights pulling on the
threaded bar C. The rotation of the pulley one way, draws the bar through the
fixed bearing, so as to rock the rotating rod and open the lights, while the rotation
of the pulley in a reverse direction, permits the threaded bar to recede, and the
lights to close by their own weight.
A metal ring or washer is preferably employed between the pulley and the
bracket, to ensure, as nearly as possible, an even bearing for the pulley to work
against; likewise, the bearing in the bracket is provided internally with a collar,
not seen in the drawings, flared out so as to give room for the threaded bar to
work to and fro, even when pulled somewhat out of line by the arm on the rotating
shaft.
In the modified arrangement shewn in Figs. 2 and 3, the bracket E is situated
near the ridge of the roof, and one of the shafts B for operating the lights is

page_text: connected to the free end of the screwed bar C by means of a loop frame C³,
pivotted to a pair of crank arms D D. A link rod D¹ connects one of these crank
arms D with a corresponding crank arm D on the shaft B on the other side
of the house, so that both shafts are rotated together by means of the one
pulley F, and the lights on both sides of the greenhouse are operated at one and
the same time.
With the gear above described, the lights can be operated with ease and accuracy,
and will only move under the influence of the pulley when the latter is intentionally
worked. The chain or band for working the pulley can hang down or be looped
up anywhere, without being tied, as the pulley will have no tendency to run back
when not held.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
Gear for operating greenhouse and other sky-lights substantially as described
and illustrated, comprising a threaded bar operating by tension to open the light, a
fixed bearing through which the threaded bar loosely passes, and a nut or pulley
internally threaded to fit the bar, and adapted to work against the fixed bearing,
in the manner set forth.
Deted thie 08th der of Inn1902
NEWTON & SON,
Agents for the Applicant.