Improvements in the Construction of Metal Cases for Timepieces, Gauges, and other Instruments.
Year: 1889

page_text: Date of Application, 26th Mar., 1889
Complete Specification Left, 27th Dec., 1889-Accepted. 22nd Mar
1890'
PROVISIONAL SPECIFICATION.
Improvements in the Construction of Metal Cases for Timepieces,
Gauges, and other Instruments.
THOMAS STRUTHERS MINNES Maker of Engineering Instruments Whitefield
Brass Works Carmichael Street, Govan, Glasgow, do hereby declare the nature of
this invention to be as follows :-
The usual method of manufacturing timepiece and gauge cases is by casting. from
patterns, the castings being then turned and finished.
Cases constructed under my invention are manufactured by rolling or spinning
sheet metal or tube (preferably of one thickness) and pressing ledges outwards or
inwards where a flange is required, inwards to hold a dial or back, outwards to
hold the case against a wall or bulkhead.
In gauge cases, I make a spun bezel or ring with the front edge pressed over
inwards to hold a glass and daylight ring, the bezel is fitted on the front of case with
screws. A little way from the front edge of case a ledge is pressed inwards, and
doubled up close, thus making an inside flange on which the dial rests and is fixed.
The under layer of the ledge is brought out to the diameter of case as in front,
and is so carried to near the back, when another flange is pressed inwards on
which the back of case rests and is fixed.
The metal of body of case is then pressed outwards to form a flange by which the
case is screwed to bulkhead &c.
The timepiece case I construct with a spun ring or bezel to hold glass, the daylight
being fixed in by soldering a groove being left into which the glass is sprung, a ring
of square wire is placed inside the back of bezel.
The bezel daylight ring, glass and square wire being all fixed together and forming
a complete bezel is hinged to the body of case:
The body of case is made by pressing the metal to form a square seat for bezel
to rest and fit on, then a ledge is carried inwards to hold the dial, at its inner
edge this ledge is pressed over on a similar ledge placed under it, the two together
forming a 2 ply ledge, giving sufficient hold for screws of movement and dial.
The bottom ledge is carried out to the diameter of case as in front where it is
soldered to the squared seat for bezel before mentioned.
The metal is then carried backwards until near the back of case when it is
curved outwards for appearance, then is extended out as a
loose circle of brass is laid in and the metal is then doubled over inwards, the flange
flange for fixing up, a
thus formed being 3 ply and gives sufficient material to hold the case up when
screwed against the bulkhead &c., and the loose circle laid in, forms the back of case.
Dated this Fifteenth day of March 1889.
COMPLETE SPECIFICATION.
Improvements in the Construction of Metal Cases for Timepieces,
Gauges, and other Instruments.
THOMAS STRUTHERS MCINNES 56 Waterloo Street Glasgow (late at Whitefield Brass
Works Govan) Manufacturer of Engineering Instruments 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 usual method of manufacturing timepiece and gauge cases is by casting from
patterns, the castings being then turned and finished.
Cases constructed under my invention are manufactured by rolling or spinning
[Price 6d.]

page_text: sheet metal or tube, and pressing ledges outwards or inwards, inwards to hold a mal
or back, outwards to hold the case against a wall or bulkhead.
In gauge cases I make a spun bezel or ring with the front edge pressed over
inwards to hold a glass and daylight ring the bezel is fitted on the front of case
with screws as usual in gauge cases. A little way from the front edge of case A
a ledge is pressed inwards, and doubled up close B thus making an inside flange
on which the dial rests and is fixed. The under layer of the ledge B is brought out
to the diameter of case as in front at A and is so carried to near the back, where
another double-layer flange C is pressed inwards on which the back of case D rests
and is fixed, as in Fig. 1. (Or the double-layer inside flange C may be a separate
piece, doubled over to hold the back and laid between the layers of outside flange E,
as in figure 2.).
The metal of body of case is then pressed outwards to form an outside double-
layer, flange E by which the case is screwed to a bulkhead or wall. _Fig. 1.
The timepiece case. is constructed with a spun ring or bezel F to hold glass, a
groove G being left, into which the glass is sprung or snapped, in same manner
as an ordinary watch glass, H and a ring of square wire is placed inside the back
of bezel F. The bezel with glass and square wire H being all fitted and fixed together
and forming a complete bezel, is hinged to the body of case at I, figure 4, and opens
and shuts on the body of case in same way as the bezel of a watch shuts on its
body. The dial plate is fixed inside the body of case.
The body of case answering to the body of a watch case in design is made by
for bezel to rest and fit on, then a ledge K
pressing the metal to form a square seat
is carried inwards to hold the dial, at its inner edge, this ledge K is pressed over
on a similar ledge L placed under it, the two together forming a 2 ply ledge, giving
sufficient hold for screws for dial.
The bottom ledge is carried out to the diameter of case as in front, where it is
I soldered to the square seat for bezel before mentioned. The metal is then carried
backwards until near the back of case, when it is carried outwards at M for
appearance, then is extended out as a flange N for fixing up to a wall or bulkhead,
a loose circle of brass O is laid in and the metal is then doubled over inwards P, the
flange thus formed being 3 ply, and gives sufficient material to hold the case up when
screwed against bulkhead or wall and the loose circle or disc O laid in forms the back
of case.
Having now particularly described and ascertained the nature of my inven
tion and in what manner the same is to be performed 1 declare that what
claim is.
First. The construction of metal cases for circular instruments, such as Stean
Gauges or Timepieces, by pressing, spinning or rolling sheet metal or tube, and
forming ledges outwards or inwards on which portions of the instruments are screwe
or for fixing them to a wall or bulkhead substantially as described.
Second. The construction of Timepiece bezel, and flange on which it fits, a
described and as shown in figure 3.
Dated this Twenty-fourth day of December Eighteen hundred and eighty-nin
THOMAS STRUTHERS MINNES.