Year: 1889

page_text: Date of Application, 25th June, 1889-Accepted, 10th Aug., 1889

page_text: sufficient pressure to suit the particular class of work about to be operated upon; as
for instance; supposing the article to be of a very tender character and one in which
stones have been set, or having a surface ornamented with enamel, then the
operator may by exerting light pressure of his foot upon the bellows, operate upon
the said article without fear of injury to either of the said ornamentations, on the
other hand, if the article to be operated upon be of a strong character then the
operator may exert full force upon the bellows, thereby producing a much harder
blast of sand and attaining the desired effect in a less time, and to any degree of
depth according to the length of time operated upon, and any intermediate degree
of depth, may be produced in a like manner. If it is desirable that the operator
shall not withdraw his hands, until any given number of articles have been operated
upon, he may place upon the perforated floor the required number of articles and
take them up singly and when blasted pass them out through the opposite arm hole.
If by accident any article or part of article, might be dropped from the operators
hands, the same is caught by the perforated floor and thus prevented from falling
into the bed of sand. The floor being above the surface of the sand.
It is found that when operating upon precious metals, there is a slight loss in
weight, this loss being in a state of dust is carried away with the outgoing air
through the opening H and passing down the passage I loses its velocity and is
precipitated with the escaping sand into the collecting box K from which it may be
collected.
Having now described one form which our invention may take, the Inventors wish
it to be understood that they do not confine themselves to this one form, as it may
take any form, to suit any particular requirement, as for instance, for operating upon
large surfaces we propose to arrange the blast nozzles in any number, the number
used to be arranged in any given form to suit the class of work to be operated upon.
for instance, in a Row or a Clustre as the case may be, and provided with any suit-
able shape cover with such openings that shall admit of any particular shape or size
article which may be too large to pass through the arm hole F.
Having now particularly described and ascertained the nature of our said inven-
tion & in what manner the same is to be performed, we declare, that what we
claim is
1st. A sand blast apparatus simple in construction with no wearing parts to get
out of order and
2nd. Which can be worked by means of a foot bellows by which the force of sand,
can be so regulated at will, to suit any class of article of Jewellery, from the most
delicate, to the more heavy kind of work met with in the metal trade and
3rd. Having an adjustable sand nozzle, by which the quantity of sand in the blast
can be readily regulated by simply raising or lowering the same in its holder and
4th. The said nozzle being so placed in the sand receptacle as shown in the
drawings, that as the sand is ejected upon the articles under the operation the said
sand gravitates to its receptacle to be again taken up by the air blast coming from
the air nozzle,and
5th. Having an outlet with a collecting box, for the purpose of arresting any
escaping sand together with any metal dust which can from time to time be separated
by any of the known methods.
6th. And initial charge of sand being sufficient no further attention is required.
Dated this 25th day of June in the year of our Lord One thousand eight
hundred and eighty nine.
ROBERT NAHUM COLDWELL.
JOSEPH DAVIS.