An Improved Device for Washing Photographic Negatives.
Year: 1891

page_text: Date of Application, 17th Apr., 1891
Complete Specification Left, 13th June, 1891-Acceptel, 18th July, 1891
PROVISIONAL SPECIFICATION.
An Improved Device for Washing Photographic Negatives.
Sir CHARLES STEWART FORBES Baronet, 23 Thurloe Square, London, S.W.
East India Agent, do hereby declare the nature of this invention to be as
follows:-
The object of this invention is to automatically change the water used for
washing exposed photographic plates. In all devices hitherto employed for this
purpose, the hyposulphate of soda is never entirely eliminated from the water in
the washing tray or bath; the syphon frequently employed for that purpose being
much too small and also continuous in its netion; while the fresh water is allowed
to continue running the denser fluid containing the hyposulphate of soda or its
equivalent is as a consequence constantly stirred up and again brought into contact
with the plates suspended in the bath or tray.
My improvement consists in mounting within the bath or washing tray one, or
more than one intermittent syphon of relatively large diameter to the inflow cock,
or equivalent, the longer leg of this syphon passes through the base of the tray
and discharges its contents into a trough so balanced, as that by means of suitable
mechanism it shall at the moment of receiving the discharge from the syphon, stop
the supply of incoming wash water, until the washing tray is completely emptied.
The balanced trough is perforated with small holes, and upon the water escaping
therefrom, it is restored by means of a spring, or counterbalance, or a suitable
valve operated by the pressure of the supply water to its original position and fresh
water readmitted.
Anril 16th 1901
FRANCIS M. ROGERS,
Agent.
COMPLETE SPECIFICATION.
An Improved Device for Washing Photographic Negatives.
Sir CHARLES STEWART FORBES Baronct 23 Thurloe Square London S.W.
East India Agent 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 :-
The object of this invention is to automatically change the water used for
washing exposed photographic plate. In all devices hitherto employed for this
purpose, the hyposulphite of soda is never entirely eliminated from the water in
the washing tray or bath; the syphon frequently employed for that purpose being
much too small, and also continuous in its action while the fresh water is allowed to
continue running; the denser fluid containing the hyposulphite of soda or its
equivalent is as a con-equence constantly stirred up and again brought into contact
with the plates suspended in the bath or tray.
My improvement consists in mounting within the bath or washing tray one, or
more than one intermittent syphon of relatively large diameter to the inflow cock
or equivalent. The longer leg of this syphon passes through the base of the tray,
and discharges its content into a trough so balanced as that by means of suitable
mechanism it shall at the moment of receiving the discharge from the syphon stop
the supply of incoming wash water, until the washing tray is completely emptied.
The balanced trough is perforated with small holes and upon the water escaping
therefrom it is restored by means of a spring, or counterbalance or a suitable

page_text: water readmitted.
To enable my invention to be better understood I will now describe the same by
means of the accompanying drawing in which :—
Fig. 1, is a part sectional elevation on line A B Fig. 2.
Fig. 2, is a plan.
Fig. 3, is a part sectional elevation on line ('D, Fig. 4 of modified form of
washer suitable for holding cage.
Fig. 4, is a plan of same.
In the drawing 1, is the bath which may be made of thin metal such as tin plate
or zine which is afterward preferably japanned: enameled or similarly treated as a
protection against chemical action.
The floor of the bath 2, is inclined as shewn in Fig. 1 and 3, and a sink formed
at 3, into which the short leg of the syphon 4, dips, the longer leg is carried through
the base of sink 3, and discharges into a trough 3, pivoted to an exterior bracket 7,
by means of lever 6, which is fitted with a counterbalance 8, adjusted by means of
set screw 9, to any desired position. The bracket is secured to the side of the bath
by riveting or soldering. The floor of the trough 5. is perforated with several
small holes 5, the collective area of these holes being considerably less than the
bore of the syphon tube. At a suitable point upon lever 6, a slot 10, is formed and
within this is secured by the pin 12, the lower end of connecting rod 13, the
upper end of which is coupled direct to the spindle 14, of valve 15. The spindle 14,
passes through a stuffing box 16, which is packed sufficiently to prevent leakage.
The valve box 15 is secured by means of the flange 17, to the side of the bath by
soldering or riveting, and is connected by a rubber or equivalent tube 18, to the
water supply. As shown in the drawing the trough is in the upward position, and
the valve 15, open, so that water can flow into the bath. The bath is fitted upon
each side and along the bottom with corrugated pieces of metal 19, 191, the grooves
in these pieces are so regulated as to hold securely the photographic plates 20.
In some cases I find it convenient to mount upon one side of the bath 4 brackets 21,
upon each of these are mounted two pins 22, 221 or more pins may be added if
required. The corrugated piece of metal 191 is removeable and has collars 23,
formed at both ends these, when slipped over pins 22, or 22 secure it in position,
thereby enabling plates of two or more sizes to be washed in the bath.
The operation of my invention is as follows:-
The photographic plates are inserted in the grooves 19, 19¹ and the water turned
on at the tap or other source and allowed to run until the intermittent syphon is
started the water discharged therefrom into the trough 5, causes it to sink and
in so doing force the valve 15. upon its seat thereby cutting off the water supply.
As the water sinks the hyposulphite solution or its equivalent is collected in and
completely discharged from the sink 3, by the syphon 4 into the perforated trough 5,
the perforations in which are so regulated as to only permit of a comparatively
slow discharge therefrom, the result being that nearly all deleterious matter is
removed before the bath is refilled with pure water by the action of the counter-
balance or its equivalent after the trough 5, has emptied itself. By the means
described I obtain a far more complete change of water than is possible when the
water is continuously running and the syphon does not intermit.
Figs. 3 and 4 show a modification of my invention designed for use with an
independent rack or cage for holding the plates. For such purposes the sides of
the bath internally are quite plain and the bottom arranged so as to permit an
ordinary rack R, to be inserted. In constructing baths for this purpose, I prefer
to pivot the perforated trough 5, to the internal bracket 25, soldered or riveted to
the bath sides, by a pin passing through a slot 10, in lever 6. and the elongated
hole 10 in the end of valve spindle 14. Upon a lug 27, forming part of the valve
box 15, a spiral spring 28, is mounted the other end of which is threaded through
a short piece of screwed wire 29, passing through the boss left upon the back of
lever 6, for the purpose, and fitted with a regulating nut 30.

page_text: By means of this modification I dispense with the counterbalance 8, shewn in
Fig. 1 and 2, and al-o the connecting rod 13. A plain spring 28, shewn in dotted
lines Fig. 3, may replace the spiral spring if more convenient, and in some cases
when the pressure of water upon the underside of the valve is sufficient to open it,
the springs may be dispensed with altogether.
In the case of large baths I sometimes employ more than one syphon in order to
empty the bath with rapidity; the additional syphon or syphons may be fixed
by the side of the first, but preferably with the inlet upon the opposite side of
the sink.
I am aware that washing baths or troughs are in use in which a continuous
action syphon is employed to maintain circulation. I do not however lay claim to
any such devices.
Having now particularly described and ascertained the nature of my said inven-
tion and in what way the same is to be performed 1 declare that what I
claim is :-
1. The combination in or with a bath for washing photographic negatives of one
or more than one intermittent syphon; which discharges the contents of the bath
into a perforated and pivoted trough in the way and manner and for effecting the
purposes herein described.
2. In a bath for washing photographic negatives the combination of a perforated
pivoted trough 5, connected to, and alternately closing and opening the inflow cock
or valve 15 by means of the discharge from the intermittent syphon or syphons 4,
and the reaction of the counterbalance spring or water pressure in the manner
described.
3. In a bath for washing photographic negatives the particular combination and
arrangement of parts whereby the supply of clean water is cut off until the bath is
emptied by the syphon or syphons as set forth.
1001
FRANCIS M. ROGERS,
Agent.