TAR-SPRAY WITH VALVE

Abstract: The invention regards a needle valve with spray nozzle for spraying hot tar or bituminous liquids on roads. For this purpose the spray-nozzle (3, 4) is also the seating of the valve. The valve-needle (11) is activated by compressed air in a pneumatic cylinder (7) with returning spring (16). The sealing of the valve-needle (11) to the pneumatic cylinder (7) is guaranteed by means of a flexible sleeve (22), attached to the valve-needle (11) and a protuberant extention (10) of pneumatic cylinder (7).

Description: Tar-spray with valve. The invention regards a needle valve with spray nozzle for spraying hot tar or bituminous liquids on roads. For this purpose the spray-nipple is also the seating of the valve. The valve-needle is activated by compressed air in an pneumatic cylinder with returning spring. The sealing of the valve-needle to the pneumatic cylinder is guaranteed by means of a flexible sleeve. From the English patent GB-A-201.993 a valve is known which is situated inside the tar tank. This valve shuts off a pipe which itseli is also situated within the tar tank. The sealing of the operating rod is situated above the molten tar level. Examples of valves where the valve is located inside the spray-bar, have seals of poiytetrafluαr-ethylene which have in practice a short life and cause many failures. The advantage of valves an top of the spray-bar is that the quantity of tar or liquid that drips out after closing the shutter is minimal. The invention aims at providing a valve with a valve-needle seal with a long life and in such a way combined with a spray-nozzle that only a minimal quantity (some drops.' leaks out after closing, while the pneumatic operation guarantees a reliable and quick responε τc the operation. The tar-spray is mounted onto a hollow bar (1) in which the hot tar flows under pressure <2>. The spray nozzle (3) is mounted in valve-ring (4) which is fastened in a plug (5) welded on bar (1). At the other side of bar (1) a plug (6) is welded which is placed in-line with plug (5). In plug (6), an pneumatic cylinder (?) is fastened. Integrated with the bottom (8) is a threaded part (9-) witn extension (10 ) . Through the bottom <S> travels the piston-rod til? which is fixed at one side in the piston (12) and which is at tne other side (13.' bulb-εhapeα and can shut off opening (14) in valve-ring ' > as a needle-valve. In tne piston-rod ( .11> a groove ',i5> can be found. The piston-rod (11) is pushed onto the vaive-rinac (4) by the force of spring (16). Through connection (17) it. is possible to lift the piston rod (11) by means of compressed air. The lifting is limited by ad sting-screw CIS), secured by bolts (19). Connection (20) serves as an outlet to the open air of the space above the piston. Pistonrαd (11) is led through the bottom (8) of the pneumatic cylinder <7). Around extension (10) with groove (21) is sleeve (22) fastened with clamp (23). The other end of sleeve (22) is tightly fastened to pistonrod (11) and is secured with a clamp (24) at the position of groove (15). The sleeve (22) is made of heatresistant and flexible material like Vitαn or siiiconrubber. The connection of the sleeve (22) to the extension (10), which slightly differs in diameter with the pistonrod Cll), and the connection, of the sleeve (22) to the pistonrod (11) are liquid tight. Sleeve (22) cannot move because the clamps (23) and (24) are placed at the position of the grooves (15) and (21). When the spray is opened by compressed air, sleeve (22) will be slightly compressed. Because the lifting is limited to a few millimeters, the elastic distortion remains small. Because the valve-ring (4) is mounted in bar (1), through which flows the hot tar (2), is in this way obtained a highly reliable shut-off tar-spray for hot tar or bituminous liquids. Because there are no means that the tar can reach the conduit of piston-rod Cll). the chance of leakage to the cylinder (70 and of blockin?. of the piston (12) is impossible.

Claims: Claims 13Needle-valve combined with spray nozzle for spraying hot tar or bituminous liquids characterized in that the sealing of the 05 needle-conduit consists of a close-fitting sleeve, made of a heatresistent flexible synthetic material, which is at one side attached to the needle and at the other side attached to a protruding concentric part of the needle-conduit. 10 23Needle-valve as claimed in claim 1], characterized in that the needle is operated by compressed air in a pneumatic cylinder with returning spring whereby the valve needle acts also as pistonrod. 33Needle-valve as claimed in claims 13 and 23, characterized in that 15 the pneumatic cylinder has an adjustable stop. 43Needle-valve as claimed in claims 13, 23 and 33 characterized in that the outlet of the pneumatic cylinder is connected to a filter.

Inventors: BURGGRAAFF TEUNIS, BURGGRAAFF, TEUNIS
Applicants: BURGGRAAFF TEUNIS, BURGGRAAFF, TEUNIS
Application year: 1988
Main classification: E01C19
IPC codes: B05B1, E01C19, F16K41