Amalgamated Dental Product.
Amalgamated Dental Company was formed with the merge of De Trey and Claudius Ask and sons. Renamed AD International in 1967
Orthodontic expansion screw. Expanders are used in orthodontics devices to apply outwardly directed force.
Invented by John Ross Pears and Edward Glenister Bell. Patented under Glenross Ltd. The earliest patent application date is 01/07/1948, which was published 02/08/1950. The patent was updated 12/03/1952 and 10/11/1954 [publication dates].
The inserted PDF file is the original patent document from the 1954 publication, as the diagram in this publication is the one that most closely aligns with the model of interest to us.
In the earlier patent documents, the diagram represents the centre hub, into which the Tommy bar is inserted for tightening, as cylindrical rather than spherical.
Older style packaging and instructions.
Newer style packaging.
Some of this information, including the first picture, is from the Australian Dental Association Queensland Branch (ADAQ) Museum.
ADAQ Museum
Amalgamated Dental Company was formed with the merge of De Trey and Claudius Ask and sons. Renamed AD International in 1967
Orthodontic expansion screw. Expanders are used in orthodontics devices to apply outwardly directed force.
Invented by John Ross Pears and Edward Glenister Bell. Patented under Glenross Ltd. The earliest patent application date is 01/07/1948, which was published 02/08/1950. The patent was updated 12/03/1952 and 10/11/1954 [publication dates].
The inserted PDF file is the original patent document from the 1954 publication, as the diagram in this publication is the one that most closely aligns with the model of interest to us.
In the earlier patent documents, the diagram represents the centre hub, into which the Tommy bar is inserted for tightening, as cylindrical rather than spherical.
Older style packaging and instructions.
Newer style packaging.
Some of this information, including the first picture, is from the Australian Dental Association Queensland Branch (ADAQ) Museum.
ADAQ Museum
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