A NEW OR IMPROVED DAMPING APPARATUS FOR LITHOGRAPHIC PRINTING OR OTHER MACHINES."
Year: 1881

page_text: LETTERS PATENT to William Powrie, of Camberwell, in the County of Surrey,
for an Invention of "A NEW OR IMPROVED DAMPING APPARATUS FOR
LITHOGRAPHIC PRINTING OR OTHER MACHINES."
PROVISIONAL SPECIFICATION left by the said William Powrie at the Office
of the Commissioners of Patents on the 2nd September 1881.
WILLIAM POWRIE, of Camberwell, in the County of Surrey. "A NEW OR
IMPROVED DAMPING APPARATUS FOR LITHOGRAPHIC PRINTING OR OTHER
MACHINES."
My Invention has for its object an improved means of automatically damping
the stone or other printing surface used in lithographic printing machines.
Hitherto this has been effected by passing the stone under rollers placed across
the machine and kept damp by band, or by a damping table or slab attached to
the carriage of the machine, also damped by hand.
Now my Invention consists in automatically supplying water to the damping
table or slab by the application and use of a trough containing water and placed
across the machine immediately under the delivery table or in any other suitable
position.
On the accompanying Drawing Figure 1 is a longitudinal section of my improved
damping apparatus, and Figure 2 a plan thereof.
From the bottom of the trough A is carried up a sheet of flannel, cloth, or other
suitable textile fabric B (or threads may be used), which is passed over the side or
edge of the trough A onto or near the upper surface of a feeding roller C for its
entire length, the feeding roller C being covered with moleskin or other suitable
material. Or, if desired, the trough A may be placed over the ordinary damping
rollers and the water conveyed to them direct in lieu of to the feeding roller C, as
described.
The water rising by capillary attraction saturates the flannel or other fabric B,
which being in contact with or in proximity to the feeding roller C keeps the

page_text: latter damp, and this dampness is conveyed from the feeding roller C to the
ordinary damping table or slab (not shown on the Drawing) as the latter passes
under it during its to and fro motion, and thence to the damping rollers and stone
in the ordinary manner.
For regulating the amount of moisture passing through the flannel or other
fabric B to the feeding roller C, the flannel or other fabric B is more or less
pressed or pinched against the trough along its entire length and on any line
intermediate to its contact with the feeding roller C and the bottom of the
trough A by an iron or other bar D secured to the edge or other convenient
part of the trough A, and capable of adjustment against the flannel or other
fabric B by set screws or nuts E in combination or not with spiral springs.
When it is not required to damp the feeding roller C the edge of the flannel or
other fabric B is turned up and hitched at each end onto hooks or other suitable
contrivance.
My Invention may also be applied to other machines where damping is required,
such as in those for damping paper for type printing purposes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Powrie in the Great Seal Patent Office on the 2nd March
1882.
WILLIAM POWRIE, of Camberwell, in the County of Surrey. "A NEW OR
IMPROVED DAMPING APPARATUS FOR LITHOGRAPHIC PRINTING AND OTHER
MACHINES."
My Invention has for its object an improved means of automatically damping
the stone or other printing surface used in lithographic printing machines.
Hitherto this has been effected by passing the stone under rollers placed across
the machine and kept damp by hand, or by a damping table or slab attached to
the carriage of the machine, also damped by hand.
Now my Invention consists in automatically supplying water to the damping
table or slab by the application and use of a trough containing water and placed
across the machine immediately under the delivery table or in any other suitable
position.
On the accompanying Drawing Figure 1 is a longitudinal section of my improved
damping apparatus, and Figure 2 a plan thereof.
From the bottom of the trough A is carried up a sheet of flannel, cloth, or other
suitable textile fabric B (or threads may be used), which is passed over the side or
edge of the trough A onto or near the upper surface of a feeding roller C for its
entire length, the feeding roller C being covered with moleskin or other suitable
material. Or, if desired, the trough A may be placed over the ordinary damping
rollers and the water conveyed to them direct in lieu of to the feeding roller Ĉ, as
described.
D
The water rising by capillary attraction saturates the flannel or other fabric B,
which being in contact with or in proximity to the feeding roller C keeps the
latter damp, and this dampness is conveyed from the feeding roller C to the
ordinary damping table or slab as the latter passes under it (at the level x, x, shewn
by dotted lines) during its to and fro motion, and thence to the damping rollers and
stone in the ordinary manner.
For regulating the amount of moisture passing through the flannel or other
fabric B to the feeding roller C, the flannel or other fabric B is more or less
pressed or pinched against the trough along its entire length and on any line
intermediate to its contact with the feeding roller C and the bottom of the
trough A by an iron or other bar D secured to the edge or other convenient
part of the trough A, and capable of adjustment against the flannel or other
fabric B by set screws or nuts in combination or not with spiral springs.
When it is not required to damp the feeding roller C the edge of the flannel or
other fabric B is turned up away from the feeding roller C by means of a swivel
bar or frame F, which is moved with the flannel or other fabric B into the position
shewn by dotted lines in Figure 1; or this bar may be dispensed with and the
flannel or other fabric B simply hitched up by any other suitable contrivance.
My Invention may also be applied to other machines where damping is required,
such as in those for damping paper for type printing purposes.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider novel, and therefore
claim as the Invention secured to me by the hereinbefore in part recited Letters
Patent is,―
1. The combination and use of flannel or textile fabric (or threads) B with the
trough A, substantially as and for the purpose herein before described and illustrated
on the accompanying Drawing,

page_text: 2. The combination and use (or not) with the flannel or textile fabric (or
threads) B and with the damping table or slab of feeding roller C, substantially
as and for the purpose herein before described and illustrated on the accompanying
Drawing.
3. The combination with the flannel or textile fabric (or threads) B of adjustable
or pinching bar D, substantially as and for the purpose hereinbefore described and
illustrated on the accompanying Drawing.
4. The combination with the flannel or textile fabric B of swivel bar or frame F,
substantially as and for the purpose hereinbefore described and illustrated by the
accompanying Drawing.
In witness whereof, I, the said William Powrie, have hereunto set my hand
and seal, this First day of March, in the year of our Lord One thousand
eight hundred and eighty two.
Witness,
E. T. HUGHES,
123, Chancery Lane,
London.
WILLIAM POWRIE. (L.S.)