In pursuance of Section 33 of the Coal Mines Act, 1911, I hereby approve, until further order, for use in all mines to which the Act applies the types of safety lamps described in the Schedule to this Order and subject to the conditions specified in the Schedule.
R. McKenna,
One of His Majesty's Principal Secretaries of State.
Whitehall,
27th June. 1913
Patterson and Company's Safety Lamps, Type "A.1" and Type "A.3".
Each of these lamps, the general design of which is shown in Plate I., is a double-gauze, flame oil lamp, with an air-feed through vertical holes in the bonnet ring. Each consists of the following essential parts:
(1.) Bonnet or Shield, of steel, with riveted seam and with a separate securely riveted crown, or of seamless steel, the bonnet and crown being in one piece.
Furnished with outlet holes immediately below the crown: Provided that the bottom of the holes shall not be less than 3/16 inch above the top of the outer gauze.
Bonnet Ring of brass, steel, or iron, riveted to the bonnet, screw threaded to fit the pillar ring, and provided with 24 vertical air-inlet holes of total area not greater than 1.2 square inches.
(2.) Pillar Ring of brass, steel, or iron, screw-threaded to take the bonnet ring, and locked thereto by means of a sliding pillar kept in position by the oil vessel.
Pillars of steel or iron, five or more (one sliding) so arranged that a straight line touching the exterior part of consecutive pillars does not touch the glass. Provided that lamps now in use, having three fixed pillars and one sliding pillar and not fulfilling this condition, may be used until lst January, 1916.
Bottom or Lock Ring of brass, steel, or iron, provided with a fixed seating for the glass, and having, when fitted with a magnetic lock, two or more ratchet teeth to engage with the bolt of the lock; provided or not with the " patent electric ignition device " shown in Plate I., so fitted as not to cause the lamp to he dangerous in an explosive atmosphere.
(3.) Gauzes of not less than 28 S.W.G. steel wire, 784 meshes to the square inch, with secure flame-tight double lap seams, or butt seams with folded edge secured on the inside by a folded metal strip; each gauze formed to fit flanges of the outside and inside base rings, and so secured to the same by punch indentations or by riveting as to make strong and flame-tight joints; the gauzes being so constructed as to form the seating for the glass necessary to hold it firmly in position, thereby preventing the lamp from being put together without them.
Internal Dimensions. |
Outer Gauze. |
Inner Gauze. |
||
|
Ins |
Ins |
Ins. |
Ins. |
Height from shoulder of base ring |
4/16 |
±1/8 |
3 13/16 |
± 1/8 |
Diameter at top |
1 15/16 |
±1/16 |
1 7/16 |
+ 3/16 -1/16 |
bottom |
1 7/8 |
±1/16 |
1 11/16 |
± 1/16 |
Provided that the lamp may be fitted with a Mueseler tube and horizontal gauze in place of the inner gauze; the horizontal gauze forming a secure and flame-tight joint with the Mueseler tube.
Provided also that the lamp may be fitted with a single gauze, of the dimensions of the outer gauze given above (with or without a gauze cap), until lst January, 1914, or. in the case of lamps now in rise, until Ist January, 1916.
(4.) Class, cylindrical:
External diameter
56 1/2 m.m. +1/2mm –1mm
Height
67mm ± 1/2mm
Furnished with top and bottom asbestos washers to ensure flame-tight joints with the gauzes and lock-ring seating.
Provided that the lamp may also be made to take a glass of the following size, viz.:
External diameter
57 1/2 mm +1/2mm –1mm
Height
60mm ± 1/2mm
(5.) Oil Vessel of brass, steel, or iron, of sufficient capacity to provide the required light for the required time as specified in paragraph 8 below; fitted with a flat 1/2-inch burner; provided or not with a winding wick adjuster, so fitted as not to cause the lamp to be dangerous in an explosive atmosphere.
(6.) Locking Devices.
In the "A.1" Lamp:- One or other of the following:-
(1.) A vertical iron bolt (held in position by a spiral spring) working within a closed or open-ended brass tube, as shown in Plate I., and so constructed that the bolt
can be withdrawn only by means of a powerful electromagnet.
(2.) An efficient lead-rivet lock, with a. horizontal or vertical lug or hinge securely attached to the lock ring or to a pillar, and a horizontal or vertical lug or staple securely soldered to the oil vessel.
In the "A.3" Lamp-An efficient lead-rivet lock, with hinge attached to a sliding band on the lock ring, and with a vertical lug securely soldered to the oil vessel, as shown in Plate I.
(7.) Reflector.-The lamp may be fitted with a removable reflector.
(8.) Provided:
(i.) That the strength of material and attachments throughout the lamp is not less than in the sample submitted for the official tests on the 15th April, 1913.
(ii.) That the oil and wick used in the lamp shall be such that the lamp shall be capable of maintaining a light of candle power not less than 0-30, as determined by a pentane standard, all round in a horizontal plane throughout a period of not less than 10 hours.
(iii.) That the lamp has been made at the works of Messrs. Patterson and Company, at Trafalgar Street, Newcastle-on-Tyne.
(iv.) That the glass shall be of an approved type, and that its dimensions shall not be outside the limits laid down in paragraph 4.(v.) That the lamp shall have marked upon it its name and the name of the maker.
This lamp, the general design of which is shown in Plate II., is a modification of Patterson and Company's Lamp, Type "A.1" and consists of the following essential parts:
(l.) Bonnet or Shield of steel with a separate securely fastened crown. Furnished with outlet holes immediately below the crown; provided that the bottom of the holes shall not be less than .6 inch above the top of the outer gauze.
(2.) Bonnet Ring of brass, steel, or iron, riveted to the bonnet and provided with five vertical air-inlet holes of total area not greater than 1.6 square inches.
Pillars of steel or iron, five or more, so arranged that a straight line touching the exterior part of consecutive pillars does not touch the Glass.
Bottom or Lock Ring of brass, steel, or iron.
(3.) Glass Retaining Ring of brass, steel, or iron, screw-threaded to engage with the lock ring:; provided or not with an inner vertical flange for protection of the inside edge of the glass. Provided that the clearance between the retaining ring and the oil vessel when the lamp is put together shall not be so great as to make it possible, under reasonable working conditions, to loosen the glass by forcing it round ill its seating, to such an extent as to impair the safety of the lamp.
(4.) Gauzes of not less than 28 S.W.G. steel wire, 784 meshes to the square inch, with secure flame-tight double-lap seam or butt seams with folded edge secured on the inside by a folded metal strip; catch gauze. formed to fit flanges of the outside and inside Base rings, and so secured
(i.) That the strength of material and attachments throughout each lamp is not less than in the sample submitted for the official tests on the 15th April, 1913.
(ii.) That the oil and wick used in each lamp shall be such that the lamp shall be capable of maintaining a light of candle power not less than 0.30, as determined by a pentane standard, all round
in a horizontal plane throughout a period of not less than 10 hours.
(iii.) That the lamps have been made at the works of Messrs. Patterson and Company, at Trafalgar Street, Newcastle-on-Tyne.
(iv.) That the glasses shall be of an approved type, and that their dimensions shall not be outside the limits laid down for Patterson and Company's "A.1" and "B.1" lamps.
(v.) That each lamp shall have marked upon it its name and the name of the maker.
(vi.) That the lamps shall be used by Officials only.
Internal Dimensions. |
Outer Gauze. |
Inner Gauze. |
||
|
Ins. |
Ins. |
Ins. |
Ins. |
Height from shoulder of base ring |
3 7/8 |
± 1/8 |
3 11/16 |
± 1/8 |
Diameter at top |
1 13/16 |
± 1/16 |
1 5/8 |
± 1/16 |
bottom |
1 7/8 |
± 1/16 |
1 11/16 |
± 1/16 |
Provided that the lamp may be fitted with a Mueseler tube and horizontal gauze in place of the inner gauze; the horizontal gauze forming a secure and flame-tight joint with the Mueseler tube.
Provided also that the lamp may be used with a single gauze, of the dimensions of the outer gauze given above (with or without a gauze cap), until 1st January, 1914, or, m the case of lamps now in use, until 1st January, 1916.
(5.) Glass, cylindrical :
Height |
60mm |
± 1/2 mm |
External diameter |
57 1/2mm |
+ 1/2mm - 1mm |
Furnished with top and bottom asbestos washers to ensure flAme-tight joints with the gauzes and retaining ring.
(6.) Oil Vessel of brass, steel, or iron, of sufficient capacity to provide the required light for the required time, as specified in paragraph 9 below; fitted with a flat burner 3 inch to ,''e inch wide (fitted or not with a porcelain body), provided or not with a winding nick adjuster, so fitted as not to cause the lamp to be dangerous in an explosive atmosphere.
(7.) Locking Devices.-An efficient lead-rivet lock, with a horizontal or vertical lug or hinge securely attached to the lock ring by a sliding band or otherwise, or to a pillar, and a horizontal or vertical lug or staple securely soldered to the oil vessel.
Provided that lamps now in use, which are fitted with screw locks, may continue in use until 1st January, 1916.
(8.) Reflector.-The lamp may be fitted with a movable reflector.
(9.) Provided:
(i.) That the strength of material and attachments throughout the lamp is not less than in the sample of Patterson and Company's lamp " A. I " submitted for the official tests on the 15th April, 1913.
(ii.) That the oil and wick used in the lamp shall be such that the lamp shall be capable of maintaining a light of candle power not less than 0.30, as determined by a pentane standard, all
round in a horizontal plane throughout a period of not less than 10 hours.
(iii.) That the lamp has been made at the works of Messrs. Patterson and Company, at Trafalgar Street, Newcastle-on-Tyne.
(iv.) That the glass shall be of an approved type, and that its dimensions shall not be outside the limits laid down in paragraph (5).
(v.) That the lamp shall have marked upon it its name and the name of the maker.
Patterson and Company’s Safety Lamps, Type “A2" and Type "A4"
Patterson and Company’s Safety Lamp, Type "B. 2."
For use by Officials.
These lamps are modifications of Patterson and Company's Lamps "A.1” , “A.3" and "B1" respectively, and are similar to them in all but the following respects:
(l.) The bonnet, bonnet ring, pillar ring, lock ring, and oil vessel may be of aluminium.
(2.) The pillars may be of brass.