This invention relates to a safety cap for use with the valve on a high-pressure gas cylinder to protect the valve against damage and tampering. Background Art

The prior art comprises U.S. Patents Nos. 1,413,502; 4,022,343? 4,301,828 _? 4,332,331; 4,352,370; 4,613,055. Disclosure of Invention

The safety cap can be removably installed on the high- pressure gas cylinder. The safety cap has a threaded fe¬ male base bracket which is removably installed on the male- threaded neck ring of the high-pressure gas cylinder. Hing- edly mounted with respect to the base bracket are two pro¬ tective shield halves which, upon being closed, entirely cover and protect the gas-cylinder's shut-off valve. Each protective shield half mounts a positive-lock hinge clamp which is clamped to the other shield half. The safety cap can be removably mounted on the cylinder's neck ring and the hinged shield halves closed and clamped together to protect the shut-off valve during transport. After deliv¬ ery to its ultimate destination, the shield halves can be fully opened to provide full and unrestricted access to operatively connect the regulator to the shut-off valve and the shield halves can again be closed and clamped to- gether in positive-lock relationship. Brief Description of Drawings

The invention should be discerned and appreciated from the drawings, wherein like reference numerals refer to similar parts throughout the several views, in which* Fig. 1 is a view showing the safety cap installed on a high- pressure gas cylinder; Fig. 2 is a side view of the safety cap by itself; Fig. 3 is a side view of the safety cap mounted on a gas cylinder, and with the two shield halves of the safety cap completely open; and Fig. 4 is a top view of the safety cap.

Best Mode for Carrying Out the Invention

In Fig. 1 of the drawings, reference numeral 1 gener-

ally refers to the invention showing the safety cap in¬ stalled on the high-pressure gas cylinder 3 with an opera¬ tively connected regulator 5 and monitoring pressure guage 7. As shown in Fig. 3, the top end of the gas cylinder 3 has a tapped hole 9 engaged by the male-threaded end 11 of a shut-off valve 13, and an external male-threaded neck ring 15 engaged by the female-threaded portion 17 of a base bracket 19. Fixedly mounted in symmetrical relationship on oppos¬ ing sides of base bracket 19, such as being welded there¬ to, are the bottom leaves 21 of common double-leaf hinges 23. Fixed to symmetrical protective shield halves 25, such as being welded thereto, are the top leaves 27 of the hinges 23. The hinges 23 have hinge pins 29 which define the lateral axes of the shield halves 25. Transversely projecting from one of the shield halves 25 are guide tabs 31 which are received in and thereby align the other shield half 25 to thereby facilitate closing together of the shield halves 25 in abutting relationship.

Fixed to shield halves 25, such as by being welded thereto, are the bottom leaves 33 of positive-lock hinge clamps 35. As shown, the bottom leaves 33 pivotally mount via cross pins 37 intermediate manipulative members 39 which pivotally mount cross pins 41 of L-shaped legs 43. Distally, the L-shaped legs 43 have small legs 45 which engage slots 47 formed in the shield halves 25. The inter¬ mediate members 39 have thumb tabs 49 which facilitate manipulative clamping down of the hinge clamps 35. In the positive-lock position of the hinge clamps 35, the pivot points defined by the cross pins 41 of the intermediate members 39 mounting the L-shaped legs 43 are below the pivot points defined by the cross pins 37 of the bottom leaves 33 mounting the intermediate members 39. To fixedly and removably mount the safety cap 1 on the gas cylinder 3, the human operator appropriately grasps the shield halves 25, guides the base bracket 19 over valve 13 and down ^" upon threaded neck ring 15 for threading engagement of its female-threaded portion 17

with threaded neck ring 15, settle the female-threaded portion 17 of base bracket 19 down upon threaded neck ring 15, and tightens same. In such described mounting of the safety cap 1 on the gas cylinder 3, the shut-off valve 13 remains installed and the shield halves 25 remain clamped together via hinge clamps 35 because the female- threaded portion 17 of the base bracket 19 has sufficient clearance so as not to interfere with shut-off valve 13. After the safety cap 1 has been mounted on the gas cylinder 3, the regulator 5 can then be operatively con¬ nected to shut-off valve 13 because- the shield halves 25 can be thereafter closed or opened and not interfere with the regulator 5 for the reason of the clearance provided by cut-away portions 51. As shown in Fig. 3, the shield halves 25 open up completely in turning about their later¬ al axes 29 to provide and afford unrestricted access radi¬ ally and longitudinally relative to the exposed shut-off valve 13 to turn valve 13 on or off; to remove, repair or replace valve 13, or to remove, repair or replace regu- lator 5.

Safety cap 1 allows the gas cylinder 3 to be delivered or transported with shut-off valve 13 installed and the shield halves 25 clamped together. At its delivery desti¬ nation and installation site, the shield halves 25 can be undamped and opened to permit the regulator 5 to be operatively connected to valve 13, and the shield halves 25 can then be closed and reclamped to prevent any damage and tampering thereafter with the shut-off valve 13.