puncturing means has a chamfered cutting edge at its lowest extremity and is hollow and closely fitted into the passage 27. The passage 33 of the puncturing element is of a predetermined diameter and controls the flow of gas, after the disc 28 is punctured, from the cartridge 13 to the interior of the shell of the fire extinguisher. Simply stated, the hollow puncturing device 32, through which the compressed gas must flow, determines by its diameter the amount of gas that is delivered into the surrounding shell of the extinguisher, once the flow of gas is effected. It is a "metering element" be cause of its control over the rate at which the gas can pass through its bore. The puncturing element 32, at its top has a flange 34 against which a spring 35 presses which holds the pointed end of element 32 above and away from the frangible disc 28, and holds the top against a stop ring 36.

A disc 39 of thin bakelite or other frangible material is located on top of stop ring 36, with a watertight seal to protect the puncturing element from corrosion.

Reporter's Statement of the Case

94 C. Cls.

The disc 39 also serves, if it is fractured, and when it is visible, as an indication that the disc 28 has been ruptured or broken and that the apparatus is not ready for use.

The patentee states in regard to the operation of the extinguisher, lines 74 to 85, page 2, of the specification:

With the extinguisher in its erect position as shown in Figure 2, operation of the extinguisher involves overturning it, grasping it by the handle 4, and jarring the extinguisher as by striking it on the floor or ground, so as to cause the disc 39 (Figure 1) to be fractured by forcible contact with the projection 15 on the inner side of the cap 16 and the frangible disc 28 to be punctured by the element 32, in connection with which it should be noted that Figure 3 illustrates the inverted operated position of the extinguisher. 6. The patentee stresses the importance of the fact that the size of the passage 33 in the puncturing element 32 controls and is vital to the operation of the device, saying, page 2, lines 97 to 105 of the specification of the patent:

In view of the fact that the diameter of the passage 33 can be accurately controlled at the time of manufacture, and in fact, subject to a discharge rate test, it will be apparent that the desired rate of discharge can be obtained whenever an extinguisher is used so that a stream of liquid fire extinguishing medium of uniform range can be maintained over a desired predetermined period of time.

In addition to the apparatus shown in Fig. 1, for the predetermination and control of the gas flow, the patentee describes and illustrates two other forms for the same purpose, shown in Figs. 4 and 5 of the drawings.

In Fig. 4 the metering of the gas is accomplished by the provision of a disc 44 in which "an accurately proportioned orifice" 43, through which the gas flows, is substituted for the bore 33 of the puncturing element 32 shown in Fig. 1.

The patentee speaks of this as follows, lines 113 to 119, page 2 of the specification:

With this construction the same advantages are had as are obtained with the construction shown in Figure 1 but in the present embodiment of the invention the

366

Reporter's Statement of the Case

passage 45, through the disc puncturing element 32 is larger than the orifice 43 and exerts no controlling effect on the rate of discharge.

As another example of gas control means the patentee in Fig. 5 employs a porous material 46 of steel wool or fibrous material such as cotton or blotting material through which the gas must pass from the cartridge 13 to the shell of the extinguisher. Describing this construction the specification states, line 123, page 2, to line 9, page 3:

In this construction a screen 47 is preferably employed and the desired predetermined quantity of porous material is inserted in the passage 22 before the strainer 20 is secured in position in the manner described in Figure 1. In this construction, as with the construction in Figure 4, the passage 45 in the disc puncturing element 32 does not exact a controlling effect on the rate of discharge. The controlling effect of the material 46, while capable of being carefully predetermined, can be checked by testing the entire assembly of the closure member 14 in a suitable fixture which, however, does not form a part of the present invention.

7. The claims in issue of the Mapes patent are Nos. 9, 10, and 11 which read as follows:

9. As an article of manufacture a vessel for containing a medium under pressure, said vessel being formed with at least one end open, a closure member for an open end of the vessel, a passage through said closure member, a frangible disc within the closure member to close the passage against the escape of the pressure medium, securing means to secure the disc over the end of the passage, a passage through the securing means, and puncturing means to puncture the disc to permit the escape of the medium when desired, said puncturing means being provided with a passage of preformed accurately controlled cross-section to permit definitely controlled discharge of the medium therethrough independently of the extent of opening of said frangible disc by said puncturing means and being formed for a closeworking fit within the passage in the securing means to prevent escape of the medium past the close-working fit to an extent which would negative the controlling effect of the passage in the puncturing means.

10. As an article of manufacture a vessel for containing a medium under pressure, said vessel being formed

Reporter's Statement of the Case

94 C. Cls.

with at least one end open, a closure member for an open end of the vessel, a passage through said closure member, means within the closure member to close the passage against the escape of the pressure medium and to permit the escape of the medium when desired, means within the closure member to control the rate of discharge of the medium from the vessel independently of the extent of opening of said passage by said last named means comprising a controlling element having a preformed fixed flow control characteristic, said controlling means comprising a restricted passage having a preformed accurately controlled cross-sectional area, and straining means within the closure member for preventing conveyance to the restricted passage of material which would clog the restricted passage and destroy its controlling effect.

11. As an article of manufacturing a vessel for containing a medium under pressure, said vessel being formed with at least one end open, a closure member for an open end of the vessel, a passage through said closure member, means within the closure member to close the passage against the escape of the pressure medium and to permit the escape of the medium when desired, means within the closure member to control the rate of discharge of the medium from the vessel independently of the extent of opening of said passage by said last named means comprising a controlling element having a preformed fixed flow control characteristic, and straining means within the closure member for preventing conveyance to the controlling means of material which would clog it and destroy its controlling effect.

THE HEIGIS PATENT IN SUIT

8. This patent is concerned with apparatus broadly the same as that shown and described in the Mapes patent in suit.

The differences reside in the terminology of the claims rather than in apparatus; for example, claim 1 of the Heigis patent, in addition to setting forth the elements contained in the Mapes patent, specifically claims a fracturable seal member 39, Fig. 1, which acts as a guard against corrosion and an indicator of the condition within the vessel.

Claim 2 contains the seal element referred to and specific reference to the flange 34 of the puncturing means 32 and compression spring 35 and stop ring 36.

Claim 3 includes with the fracturable seal means for holding the puncturing means out of contact with the frangible disc 28.

The Mapes patent has the definite object of metering or controlling gas flow; the Heigis patent adds a fracturable seal 39 to the apparatus of the Mapes patent.

Identical drawings and numerals are used in both patents, Fig. 2 of Heigis corresponds to Fig. 1 of Mapes, while Fig. 1 of Heigis is the same as Fig. 2 of Mapes.

The claims of the Heigis patent are set forth below:

1. As an article of manufacture a vessel for containing a medium under pressure, said vessel being formed with at least one end open, a closure member for an open end of the vessel, a passage through said closure member, a frangible disc within the closure member to close the passage against the escape of the pressure medium, securing means to secure the disc over the end of the passage, a passage through the securing means,