Antithief devices

Claim 2

In a hydraulic brake system of a vehicle having a master cylinder and brake cylinders, between the master cylinder and the brake cylinders, a device for preventing the unauthorized movement of the vehicle comprising: a. a body portion having a through passageway, an inlet in the body portion to the passageway intermediate the ends of the passageway, the master cylinder communicating with the said inlet, and a valve seating between said inlet and one of the ends of the passageway, the said one end communicating with the brake cylinders of the vehicle and the other end of the passageway having a screw thread and a radial aperture, b. a valve member having a head and a stem and arranged slidably within the said passageway of the body portion so that the valve head may seat on the side of the valve seating which is remote from the said inlet, with the valve stem extending past the seating and the inlet, the valve head comprising a cap of plastics material fitted onto the valve stem and having an aperture communicating with a bore in the valve stem which bore has an exit hole communicating with tHe said passageway, c. a screw-threaded member screwed into the said other end of the passageway so that it abuts the end of said valve stem when said valve head is seated on said valve seating, d. a cylinder lock mounted in the said other end of the passageway and comprising a sleeve and a cylinder rotatable in the sleeve by means of a key, the sleeve having a radial aperture therein registering with the radial aperture in the said other end of the passageway and the cylinder having a cam surface registering with the said radial aperture in the sleeve, the screw-threaded member being rotatable with the cylinder to screw further into the passageway and move the valve head off its seating, e. a fluidtight seal for the said other end of the passageway, f. a second valve member including a ball portion located within the bore in the valve stem, g. a spring within the valve stem which normally urges the ball portion of the said second valve member against the said aperture in the valve head to seal the said aperture, but which permits the passage of excess brake fluid in the direction from the brake cylinders to the master cylinder, and h. a plunger-operated electric switch mounted on the body portion with the plunger passing through the radial apertures in the said one end of the passageway and the lock sleeve to abut the cam surface, so that when the lock cylinder is rotated the plunger will be actuated.

Claim 3

A device as claimed in claim 1 in which the switch is a double-pole single-throw switch.

Claim 4

A device as claimed in claim 1 including a spring arranged within the said passageway in the body portion to urge the said valve head onto the said valve seating.

Claim 5

A device as claimed in claim 1 in which the said plastics material comprises an acetal resin.

Claim 6

A device as claimed in claim 1 in which the said plastics material comprises a reinforced polyamide plastic.

Claim 7

In a hydraulic brake system of a vehicle having a master cylinder and brake cylinders, between the master cylinder and the brake cylinders, a device for preventing the unauthorized movement of the vehicle comprising: a. a body portion having a through passageway with screw-threaded ends, an inlet in the body portion to the passageway intermediate said ends, the master cylinder communicating with said inlet, and a valve seating between said inlet and one of the ends of the passageway, the other end of the passageway having a radial aperture therein, b. a valve member having a head, a stem, and a sealing ring surrounding the root of the stem and abutting the head, the member being arranged slidably within the said passageway of the body portion so that the valve head may seat on the side of the valve seating which is remote from the said inlet, with the sealing ring interposed between the head and the seating and the valve stem extending past the seating and the inlet, the valve head comprising a cap of plastics material having a screw thread and being screwed onto a corresponding screw thread on the root of the stem, the cap also having an aperture communicating with a bore in the valve stem which bore has a radial exit hole communicating with the said passageway, c. a screw-threaded plug screwed into the said one end of the passageway and having a through bore communicating at the inner end with the passageway and at the outer end with the brake cylinders, d. a fluidtight seal between the said plug and the wall of the said one end of the passageway, e. a screw-threaded member screwed into the said other end of the passageway so that it abuts the end of said valve stem when said valve head is seated on said valve seating, f. a cylinder lock mounted in the said other end of the passageway and comprising a sleeve and a cylinder rotatable in the sleeve by means of a key, the sleeve having a radial aperture therein registering with the radial aperture in the said other end of the passageway and the cylinder having a cam surface regisTering with the said radial aperture in the sleeve, the screw-threaded member being rotatable with the cylinder to screw further into the passageway and move the valve head off its seating, g. a fluidtight sealing member for the said other end of the passageway fitted around the valve stem intermediate the exit hole of the said bore in the valve stem and the said other end of the passageway, h. a second valve member including a ball portion located within the bore in the valve stem, i. a spring within the valve stem which normally urges the ball portion of the said second valve member against the said aperture in the valve head to seal the said aperture, but which permits the passage of excess brake fluid in the direction from the brake cylinders to the master cylinder, and j. a plunger operated electric switch mounted on the body portion with the plunger passing through the radial apertures in the said one end of the passageway and the lock sleeve to abut the cam surface, so that when the lock cylinder is rotated the plunger will be actuated.

Claim 8

In a hydraulic brake system of a vehicle having a master cylinder and brake cylinders, between the master cylinder and the brake cylinders, a device for preventing the unauthorized movement of the vehicle comprising: a. a body portion having a through passageway with screw-threaded ends, an inlet in the body portion to the passageway intermediate said ends, the master cylinder communicating with said inlet, and a valve seating between said inlet and one of the ends of the passageway, the other end of the passageway having a radial aperture therein, b. a valve member having a head, a stem, and a sealing ring surrounding the root of the stem and abutting the head, the member being arranged slidably within the said passageway of the body portion so that the valve head may seat on the side of the valve seating which is remote from the said inlet, with the sealing ring interposed between the head and the seating and the valve stem extending past the seating and the inlet, the valve head comprising a cap of plastics material having a screw thread and being screwed onto a corresponding screw thread on the root of the stem, the cap also having an aperture communicating with a bore in the valve stem which bore has a radial exit hole communicating with the said passageway, c. a screw-threaded plug screwed into the said one end of the passageway and having a through bore communicating at the inner end with the passageway and at the outer end with the brake cylinders, d. a fluidtight seal between the said plug and the wall of the said one end of the passageway, e. a screw-threaded member screwed into the said other end of the passageway so that it abuts the end of said valve stem when said valve head is seated on said valve seating, f. a cylinder lock mounted in the said other end of the passageway and comprising a sleeve and a cylinder rotatable in the sleeve by means of a key, the sleeve having a radial aperture therein registering with the radial aperture in the said other end of the passageway and the cylinder having a cam surface regisTering with the said radial aperture in the sleeve, the screw-threaded member being rotatable with the cylinder to screw further into the passageway and move the valve head off its seating, g. a fluidtight sealing member for the said other end of the passageway fitted around the valve stem intermediate the exit hole of the said bore in the valve stem and the said other end of the passageway, h. a second valve member including a ball portion located within the bore in the valve stem, i. a spring within the valve stem which normally urges the ball portion of the said second valve member against the said aperture in the valve head to seal the said aperture, but which permits the passage of excess brake fluid in the direction from the brake cylinders to the master cylinder, and j. a plunger operated electric switch mounted on the body portion with the plunger passing through the radial apertures in the said one end of the passageway and the lock sleeve to abut the cam surface, so that when the lock cylinder is rotated the plunger will be actuated.

Claim 9

A device as claimed in claim 6, in which the switch is a double-pole single-throw switch.

Claim 10

A device as claimed in claim 6 in which the said screw-threaded plug has a seating for a compression spring at its inner end, and in which the device includes a compression spring seating at one end on the spring seating of the plug and at its other end against the said valve head to urge the valve head onto the said valve seating.

Claim 11

A device as claimed in claim 6 in which the said plastics material comprises an acetal resin.

Claim 12

A device as claimed in claim 6 in which the said plastics material comprises a reinforced polyamide plastic.