Stirrer motor support

A stirrer motor, for a flask having a neck through which a drive shaft extends from the motor to an agitating device in the flask, is arranged to be supported by means located in the neck.

The invention relates to means for mounting a stirrer motor and for a 
stirrer motor mounted by such means. 
It is a well-known laboratory technique to employ a stirrer motor, commonly 
electric, to drive a paddle or other agitating means in liquid contained 
in a vessel, commonly closed, such as a flask having one or more necks via 
a drive shaft passing through the neck or one of the necks of the flask, 
the stirrer motor being supported outside the flask by means of a retort 
stand. However, the required precise location of the motor relative to the 
flask is tedious to achieve and it is an object of the invention to 
obviate this disadvantage. 
According to the invention there is provided mounting means for a stirrer 
motor for driving agitating means in a flask or the like container having 
a neck by drive means passing through the neck, said mounting means 
comprising support means releasably supportable by the said neck. 
Preferably the support means are for support in, and may also sealingly 
close, said neck.

In the FIGURE, stirrer motor 2 is a 6-volt DC reversing motor supplied with 
electric current by cable 4 and provided with a reducing gearbox 6 having 
an output shaft 8. 
The motor mounting 10 is secured to a brass angled bracket 12 of limb 14 
perpendicular to the motor axis is provided with an aperture for the shaft 
8 and a sealing washer 16 is located about the shaft 8 between the gearbox 
and the bracket portion 14. 
Bracket 12 is mounted on a flanged disc 18 of p.t.f.e. by means of bolts 20 
(1 only shown) passing through the disc and entering tapped holes in a 
p.t.f.e. lower member 22. 
The motor, gearbox, bracket and cable are enclosed within a cylindrical 
p.t.f.e. cover 24 which is threaded for engagement with disc 18 and at the 
other end for screw engagement with circular lid 26. The disc 18 is 
provided with a hole 28 for the emergence of cable 4, the hole being a 
tight fit about the cable. 
The lower portion 22 which is bored to accommodate extension shaft 30 
terminates in a frustoconical portion 32 of which the taper is according 
to an appropriate British standard for stoppers for flasks of the type 
with which the stirrer is intended to be used. The member 32 is also 
provided with sealing rings 34 whereby the portion 32 may be sealingly 
engaged in the neck of a flask. 
Also shown in the FIGURE but not being part of the invention is a glass 
stirrer rod of conventional type which terminates in a paddle or other 
agitating means not shown. The upper end of the stirrer rod is provided 
with a p.t.f.e. collar 36 which supports a rubber O-ring 38 by means of 
which the rod can be sealingly engaged to the lower end of plastic 
extension shaft 30 by means of screwed collar 40. 
As shown, the shafts 8 and 30 whilst being symmetrical with respect to 
portion 32 of lower body 22, are asymmetrical with respect to disc 18 and 
the motor cover provided by cylinder 24 and lid 20 so that appropriate 
orientation of the apparatus in the neck of a flask the motor housing can 
be accommodated where it is less likely to interfere with other parts of 
the apparatus. 
If the stirrer motor is to be used with a flask having a neck for which the 
portion 32 is not an appropriate fit, an adaptor may be provided 
comprising an elongate hollow stem having a lower external surface 
appropriate to the flask and an upper internal surface appropriate to the 
body 32. 
With the unit described mounted with the portion 32 acting as a stopper 
seated directly in the neck of a flask or seated in the neck of an adaptor 
which in turn seats in the neck of the flask, with the shafts 8 and 30 
passing through the stopper, the flask and stirrer constitute an integral 
body. Thus the flask can be moved without disturbing the relative position 
of the flask and stirrer. Provided that the flask itself is satisfactorily 
supported, for example by means of a retort stand or in a heating mantle, 
the stirrer motor does not require any outside support. 
In other embodiments a 12-volt motor may be employed and different 
materials of construction may be used. Thus the parts made of 
polytetrafluoroethylene (p.t.f.e.) in the first mentioned embodiment may 
be made of other plastics material such as nylon.