Tamperproof lock with shock absorber

Claim 2

In a fire hydrant including a bonnet having an aperture, a housing having an internal chamber, a threaded operating rod extending within the housing chamber coupled to a yoke, and a plunger coupled to the yoke for opening and closing a valve, a tamperproof lock comprising: a spring mounted at one end on a housing; power transmitting means threadedly mounted on a threaded operating rod extending within a housing chamber for transmitting power to said threaded rod against said spring; hydraulic means operatively associated with said power transmitting means for preventing sudden closing of the hydrant valve; and a swivel plate freely mounted on said power transmitting means for rotational movement thereon, said swivel plate having a contoured hub portion adapted to fit within a bonnet aperture, said hub portion being exposed to the exterior of the bonnet.

Claim 3

The tamperproof lock according to claim 1 including power applying means removably mounted on the bonnet for applying power substantially along the axis of the operating rod to move the operating rod against said spring and said hydraulic means, said power applying means comprising a collar having a passage, means reciprocable in said collar passage for contacting said swivel plate hub portion to apply to said power transmitting means, locking means pivotably connected to said collar, means pivotably connected to said locking means for preventing axial and rotational movement of said collar, said preventing means having a contoured portion for substantially flush contact with the exterior of said collar, said preventing means being adapted for removable coupling to the exterior of the bonnet.

Claim 4

The tamperproof lock according to claim 2 wherein said means reciprocable in said collar passage is adapted to matingly contact said swivel plate hub portion.

Claim 5

The tamperproof lock according to claim 1 wherein a solid film lubricant is interposed between said swivel plate and power transmitting means.

Claim 6

In a fire hydrant including a housing having an internal chamber and an internally threaded portion, a threaded operating rod extending within the housing chamber coupled to a yoke, and a plunger coupled to the yoke for opening and closing a valve, the combination comprising: a modified retaining ring threadedly mounted on an internally threaded portion of a housing; an operating nut converter threadedly mounted on a threaded operating rod extending within a housing chamber; a pressure plate threadedly mounted on said operating nut converter, said pressure plate having an annular recess formed in its underside and a circular recess formed in its topside; a swivel plate freely mounted in said pressure plate circular recess for rotational movement therein, said swivel plate having a conically shaped central hub portion; a piston ring threadedly mounted on said operating nut converter; said housing chamber containing hydraulic fluid for contact with said piston ring; and a spring mounted at one end on the housing and adapted to fit at the other end within said pressure plate annular recess whereby said spring exerts an upward force against the underside of said pressure plate.

Claim 7

In a fire hydrant including a housing having an internal chamber and an internally threaded portion, a threaded operating rod extending within the housing chamber coupled to a yoke, and a plunger coupled to the yoke for opening and closing a valve, the combination comprising: a modified retaining ring threadedly mounted on an internally threaded portion of a housing; an operating nut converter threadedly mounted on a threaded operating rod extending within a housing chamber; a pressure plate threadedly mounted on said operating nut converter, said pressure plate having an annular recess formed in its underside and a circular recess formed in its topside; a swivel plate freely mounted in said pressure plate circular recess for rotational movement therein, said swivel plate having a conically shaped central hub portion; a piston ring threadedly mounted on said operating nut converter; said housing chamber containing hydraulic fluid for contact with said piston ring; and a spring mounted at one end on the housing and adapted to fit at the other end within said pressure plate annular recess whereby said spring exerts an upward force against the underside of said pressure plate.

Claim 8

The combination according to claim 5 including a bonnet coupled to the housing, said bonnet having an aperture for receiving said conically shaped central hub portion of said swivel plate and a wall provided with a pair of holes in the exterior thereof, and means removably mounted on said bonnet for exerting a force substantially along the axis of the operating rod to move the rod against said spring and said hydraulic fluid, said exerting means comprising a screw member having a nut at one end and a conically shaped recess at the other end, said screw member being adapted to matingly contact said conically shaped central hub portion of said swivel plate, a collar having an internally threaded passage for threadedly engaging said screw member to permit said screw member to move reciprocatingly therein, locking means pivotably connected to said collar at opposed ends thereof, a pair of arms pivotably connected to said locking means at opposed ends of said collar, each of said arms having a pin adapted to fit securely within one of said bonnet wall holes and a contoured portion for substantially flush contact with the exterior of said collar to prevent axial and rotational movement of said collar.

Claim 9

The combination according to claim 5 wherein a solid film lubricant is interposed between said swivel plate and pressure plate circular recess.

Claim 10

In a fire hydrant including a bonnet having an aperture, a housing having an internal chamber, a threaded operating rod extending within the housing chamber coupled to a yoke, and a plunger coupled to the yoke for opening and closing a valve, a tamperproof lock comprising: a spring mounted at one end on a housing; power transmitting means threadedly mounted on a threaded operating rod extending within a housing chamber for transmitting power to said threaded rod against said spring; hydraulic means operatively associated with said power transmitting means for preventing sudden closing of the hydrant valve; a swivel plate freely mounted on said power transmitting means for rotational movement thereon, said swivel plate having a contoured hub portion adapted to fit within a bonnet aperture, said hub portion being exposed to the exterior of the bonnet; and power applying means removably mounted on the bonnet for applying power substantially along the axis of the operating rod to move the rod against said spring and said hydraulic means by contacting the contoured hub portion of said swivel plate.

Claim 11

In a fire hydrant including a bonnet having an aperture, a housing having an internal chamber, a threaded operating rod extending within the housing chamber coupled to a yoke, and a plunger coupled to the yoke for opening and closing a valve, a tamperproof lock comprising: a spring mounted at one end on a housing; power transmitting means threadedly mounted on a threaded operating rod extending within a housing chamber for transmitting power to said threaded rod against said spring; hydraulic means operatively associated with said power transmitting means for preventing sudden closing of the hydrant valve; a swivel plate freely mounted on said power transmitting means for rotational movement thereon, said swivel plate having a contoured hub portion adapted to fit within a bonnet aperture, said hub portion being exposed to the exterior of the bonnet; and power applying means removably mounted on the bonnet for applying power substantially along the axis of the operating rod to move the rod against said spring and said hydraulic means by contacting the contoured hub portion of said swivel plate.

Claim 12

In a fire hydrant including a housing having an internal chamber and an internally threaded portion, a threaded operating rod extending within the housing chamber coupled to a yoke, and a plunger coupled to the yoke for opening and closing a valve, the combination comprising: a modified retaining ring threadedly mounted on an internally threaded portion of a housing; an operating nut converter threadedly mounted on a threaded operating rod extending within a housing chamber; a pressure plate threadedly mounted on said operating nut converter, said pressure plate having an annular recess formed in its underside and a circular recess formed in its topside; a swivel plate freely mounted in said pressure plate circular recess for rotational movement therein, said swivel plate having a conically shaped central hub portion; a piston ring threadedly mounted on said operating nut converter; said housing chamber containing hydraulic fluid for contact with said piston ring; a spring mounted at one end on the housing and adapted to fit at the other end within said pressure plate annular recess; a bonnet coupled to the housing, said bonnet having an aperture for receiving said conically shaped central hub portion of said swivel plate and a wall provided with a pair of holes in the exterior thereof; and means removably mounted on said bonnet for exerting a force substantially along the axis of the operating rod to move the rod against said spring and said hydraulic fluid by contacting the central hub portion of said swivel plate.

Claim 13

In a fire hydrant including a housing having an internal chamber and an internally threaded portion, a threaded operating rod extending within the housing chamber coupled to a yoke, and a plunger coupled to the yoke for opening and closing a valve, the combination comprising: a modified retaining ring threadedly mounted on an internally threaded portion of a housing; an operating nut converter threadedly mounted on a threaded operating rod extending within a housing chamber; a pressure plate threadedly mounted on said operating nut converter, said pressure plate having an annular recess formed in its underside and a circular recess formed in its topside; a swivel plate freely mounted in said pressure plate circular recess for rotational movement therein, said swivel plate having a conically shaped central hub portion; a piston ring threadedly mounted on said operating nut converter; said housing chamber containing hydraulic fluid for contact with said piston ring; a spring mounted at one end on the housing and adapted to fit at the other end within said pressure plate annular recess; a bonnet coupled to the housing, said bonnet having an aperture for receiving said conically shaped central hub portion of said swivel plate and a wall provided with a pair of holes in the exterior thereof; and means removably mounted on said bonnet for exerting a force substantially along the axis of the operating rod to move the rod against said spring and said hydraulic fluid by contacting the central hub portion of said swivel plate.

Claim 14

A fire hydrant including a valve, comprising: a bonnet; a housing coupled to said bonnet having an internal chamber; a threaded operating rod extending within said housing chamber for causing a valve to open and close; a spring mounted at one end on said housing; power transmitting means threadedly mounted on said operating rod for transmitting power to said rod against said spring; hydraulic means operatively associated with said power transmitting means for preventing sudden closing of the hydrant valve; and swivel means rotatably mounted on said power transmitting means, said swivel means having a contoured portion exposed to the exterior of said bonnet.

Claim 15

A fire hydrant including a valve, comprising: a bonnet; a housing coupled to said bonnet having an internal chamber; a threaded operating rod extending within said housing chamber for causing a valve to open and close; a spring mounted at one end on said housing; power transmitting means threadedly mounted on said operating rod for transmitting power to said rod against said spring; hydraulic means operatively associated with said power transmitting means for preventing sudden closing of the hydrant valve; and swivel means rotatably mounted on said power transmitting means, said swivel means having a contoured portion exposed to the exterior of said bonnet.

Claim 16

Apparatus according to claim 10 including power applying means removably mounted on said bonnet for applying power substantially along the axis of the operating rod to move the rod against said spring and said hydraulic means by contacting the contoured portion of said swivel means.