[F1Cover fitted with stirrerE+W+S
Textual Amendments
F1Sch. 2 repealed (10.9.1992) by S.I. 1992/1811, reg. 12(2), Sch. 3 Pt. I (by reg. 12(1) it is provided that this repeal shall have effect in relation to the value of the flash point of petroleum-spirit and the methods for determining it).
Provision may be made in the cover for the reception of a stirrer which projects into the oil cup, for use with viscous materials only.
A bush is mounted on the cover in a position diametrically opposite the thermometer mounting and its length is such and it is set at such an angle that the stirrer rod clears the oil-level gauge and the blades operate below the level of and without fouling the thermometer bulb. The bush is placed as near as practicable to the outer edge of the cover.
The stirrer consists of a round stem having four blades or vanes silver soldered in place at one end. A collar is fixed on the stem so that when the stem is inserted into the bush from below, it is arrested at a position such that the correct length protrudes into the oil cup. The top end of the stem is reduced and screwed.
A long sleeve having an internally screwed, knurled knob soldered to its upper end, is passed over the upper end of the stem and screwed home. The length of the sleeve is such that a flat-faced collar at its lower end just comes into contact with the upper end of the bush, leaving the stirrer free to rotate without appreciable vertical play.
A flat-headed cylindrical plug is provided for insertion in the bush when the stirrer is not in use.
Material:—brass or gun-metal.
| ——— | Dimension | Tolerance |
|---|---|---|
| Stem, length overall | 4in. | ±0·1in. |
| ,, ,, Lower end to point of attachment of blades. | Approx. 0·1in. | |
| ,, ,, Lower end to upper surface of collar. | 1·9in. | ±0·1in. |
| ,, ,, Upper surface of collar to lower end of thread. | 2in. | ±0·1in. |
| ,, ,, Diameter of stem | Approx. 0·125in. | |
| ,, ,, ,, of collar | Approx. 0·25in. | |
| ,, Thread | 7 B.A. | |
| Blades, thickness | 17 I.W.G. | |
| ,, Length excluding root | 0·5in. | ±0·01in. |
| ,, Breadth (all corners of blades rounded). | 5/16 (0·3125in.). | ±0·01in. |
| ,, Blade angle | Approx. 45_ | |
| Sleeve. Length, to suit stem, giving free rotation with no appreciable vertical play when screwed home. | ||
| Diameter of bore | Sliding fit on stem. | |
| Diameter of collar | Approx. 0·25in.] |