AU618316B2 - Improvements in or relating to radiator caps - Google Patents

Description

I MAIL O FFICR SIXTY DOLLARS I I I Imp I N AUSTR~ALIA 618 3m? 6 PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Short Titlc: Int. CI: Application Number: Lodged: Comqpl ete Specification-Lodged: Accepted: Lapsed: Published: Prior4t: Related Art: Name of Applicant: Address of Applicant: TO BE COMPLETED BY APPLICANT AUTOCAPS (AUST) PTY. LTD.

7 MONTEFIORE STREET, FAIRFIELD, VIC. 3078.

Actual Inventor: M00)6700~ Address for Service: :21/02/09 PETER R. MAY GRIFFITH HACK CO., 601 ST. KILDA ROAD, MELBOURNE, VIC. 3004,

AUSTRALIA.

Complete Specification for the invention entitled: "IMPROVEMENTS IN OR RELATING TO. RADIATOR CAPS" The following statement is a full description of this invention, including the best method of performing it known to me: PF/CPIF/2/80 Company stamps or seals should not be used. No legalisation is necessary.

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2 Ott 1 SrlL ft 1 I (f (tI IMPROVEMENTS IN OR RELATING TO RADIATOR CAPS This invention relates to improvements in or relating to radiator caps and in particular relates to a pressure cap suction valve assembly for use in a radiator cap.

A conventional radiator cap is shown in Figure 1 and comprises a cap member A formed as a metal disc B having a downwardly extending outer peripheral skirt C and a pair of diametrically opposed lugs D turned inwardly from the lower edge of the skirt C. The lugs D allow the cap to be a "bayonet" type fit on an associated radiator filler neck (not shown). Some radiator caps do 1;1 ;I L i 3 away with the lugs D and have the interior of the skirt threaded to allow screw threaded attachment to the filler neck. The central part of the disc B is formed with a downwardly extending well portion E to which the upper end of a downwardly extending tubular stem F is connected by rivet type connection G. The lower end of the stem F carries a plunger member H having a central aperture J whereby the plunger member is slidably fitted to the stem F and has an out-turned flange K to serve as a stop against which the plunger H is biased by a helical compression spring L. The plunger H terminates in a disc portion M having an inwardly turned flange N. A pressure cap suction valve assembly W is crimped onto the flange S portion N. The radiator cap as shown in Figure 1 also 15 includes a polymeric skirt and seal assembly T that is fro* A mounted on the stem F against the inside of the cap member A and is located therein by engagement of the compression spring L. The skirt and seal assembly T is of the kind described in British Patent 2030119.

The pressure cap suction valve assembly W comprises a dish-shaped suction valve body P terminating in an annular flange R that is crimped onto the flange N of the. plunger H. The valve body P has a central aperture through which flared double-headed rivet S is positioned, to clamp a circular polymeric seal Z against the outside of the suction valve body. The valve member comprises a valve plate Y with a central spigot X that is riveted to the plate Y to extend inwardly towards the radiator and through the rivet S. The valve member is held in compression against the external surface of the seal Z by a small coil spring 0 that acts between a flange on the end of the spigot X and the rivet S.

In use, as the radiator cap is attached to the filler neck of a radiator (not shown) the plunger is compressed against the coil spring as the polymeric seal Z is placed in firm positive engagement on the top of the 4 filler neck. The skirt and seal assembly T also acts as a secondary seal against an upper portion of the filler neck.

The radiator cap described above is for use in assemblies that have both coolant recovery and non-recovery features.

These days most radiator assemblies operate as a sealed system. However, because of the large pressures that are generated when the coolant gets very hot there needs to be some release of excess pressure. Release of excess pressure (up to 18 psi) is normally effected by displacement of the plunger H against the compression spring L. Escaping coolant enters a collection line (not shown) to a suitable overflow receptacle. When the pressure within the radiator drops so that it is less than So atmosphere, the suction valve assembly opens so that the valve member V moves out of contact with the seal Z to allow coolant held in the external receptacle to be drawn

K

back into the assembly.

The pressure cap suction valve assembly described above and illustrated in Figure 1 suffers from the disadvantage that it comprises six different components.

The valve member includes the valve plate Y and spigot X that is riveted to the centre of the valve plate. The valve body is attached to the seal member by a double-headed rivetS and a coil spring O is positioned between the interior of the spigot and the interior of the valve body. The assembly of these components is labour intensive and has resulted in a high occurrence of rejects basically caused by defective riveting.

The present invention aims to provide an assembly that simpler and cheaper to make and less prone to failure in use.

According to the present invention there is provided a pressure cap suction valve assembly comprising a suction valve body having an aperture therein, a polymeric seal having an integral spigot that clips through the aperture in the valve body to secure the seal to the valve body, a valve stem moulded in plastics in one piece to define a valve seat and a projecting shank that extends through the spigot in the seal and the aperture in the valve body, the valve stem being arranged to seat against the valve body, and a spring mounted on the shank to act between one end of the shank and the valve body to hold the valve seat and polymeric seal in sealed engagement against the valve body.

One embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a cross-sectional view of a radiator cap of the prior art; i Figure 2 is a cross-sectional view of a pressure cap suction valve assembly according to the present invention; Figure 3 is an enlarged cross-sectional view of a valve stem forming part of the suction valve assembly of Figure 2; and Figure 4 is an enlarged cross-sectional view of a seal forming part of the suction valve assembly of Figure 2.

As shown in Figure 2 the suction valve assembly that constitutes the embodiment of the present invention comprises a suction valve body 10 comprising a disc 11 that presents a concave interior surface bounded by a flange 12 that, in use, can be crimped onto the flange N formed on the end of the plunger H as shown in Figure 1. The valve body is preferably constructed of brass but may also be constructed of 302/4 stainless steel. The valve body 10 is also provided with an annular inwardly projecting rib 14 and a planar mounting portion 15 terminating in a circular aperture 16 that is central of the valve body. A polymeric seal member 20 shown in detail in Figure 4, comprises a planar disc 21 with an outwardly extending hollow spigot 22 formed with a 6 radially outwardly extending annular bulbous portion 23.

The bulbous portion 23 defines a narrow annular groove 24 between the internal surface of the disc 21 and the bulbous portion 23. As shown in Figure 2 the spigot 22 is arranged to be a close fit within the aperture 16 in the valve body and the bulbous portion 23 is of diameter greater than the diameter of the aperture so that the rubber seal in effect clips into the aperture in the valve body with the planar portion of the disc 21 extending parallel to the mounting portion 15 and then extending slightly spaced from the curved disc 11 of the valve body to terminate adjacent the edge of the valve body as shown in Figure 2.

The valve member 40 illustrated in Figures 2 and 3 is a plastics moulding and comprises a valve plate 41 with a centrally outwardly extending shank 42 that terminates in a tapered head 43. The shank 42 is provided with a slight inwardly necking 44 adjacent the start of the head 43 to define annular shoulder 45. The valve plate 41 is provided with an annular tapered shoulder 46 and an inwardly extending annular lobe 47.

As shown in Figure 2 the lobe 47 engages the exterior surface of the rubber seal 20 and thus any force between the valve member 40 and the seal 20 is transmitted through the lobe 47. The shank 42 is of a diameter that is smaller than the internal diameter of the spigot 22 on the seal so that there is an annular gap 50 between the shank and the spigot. The shank 42 extends through the spigot 22 on the seal 20 and terminates past the extremity of the skirt 12 on the valve body 10. A conical compression spring 60 is mounted on the shank 42 of the valve member with the larger end 61 located between the rib 14 on the interior surface of the valve body and the bulbous end 23 of the spigot 22 on the valve member. The narrow end 62 of the conical spring 60 is arranged to engage the shoulder 45 formed at the start of 7 7 the head portion 43 of the valve member. In this manner the spring 60 is firmly located in position around the shank 42 of the valve member. The spring 60 urges the valve member 40 against the rubber seal 20 to prevent passage of air or liquid in the direction of the arrow B in Figure 2. Thus there is no escape of pressure within the radiator past the valve seat defined by the lobe 47.

When a vacuum of between 0.3 to 1.0 psi is set up by the pressure differential between the interior and the exterior of the radiator, i.e. between upper and lower sides of the valve, the valve member 40 moves away from 0s00 °o~o the seal 20 against the spring 60 and allows entry of 00 either air or coolant as required past the shank 42, oaeo through the gap 50 and into the radiator via the lobe 47.

o 15 The lobe 47 on the valve member 40 has a radius 00 of curvature specifically designed to provide an annular o00 C seating surface that is balanced with the calibration of the spring to ensure exact vacuum release.

a The positive pressure release is effected at a 20 much higher pressure (up to 18 psi) by the whole assembly moving on the plunger H against the much stronger 0 o compression spring L formed in the radiator cap shown in Figure 1. The valve member 40 is moulded of a glass filled nylon 66 in a single piece thereby doing away with the composite plate and riveted spigot of the prior art.

S0 The valve seal 20 is provided with an integrally moulded Sspigot that allows the seal to be clipped within the aperture formed in the valve body thereby doing away with the complicated double-headed rivet S that is illustrated in Figure i. The positive location of the tapered conical spring 60 which is manufactured from 302/4 stainless steel ensures effective operation of the assembly.

8 It has been discovered that the suction valve assembly described above is simpler, quicker and therefore cheaper to make without being prone to the 1 to 4% reject rate that was experienced with the assembly illustrated in Figure 1.

The assembly can be used on radiator systems that have a coolant recovery or non-coolant recovery facilities. It is understood that the assembly can be used in conjunction with the radiator cap illustrated in Figure 1. However, it is further understood that the invention is not limited to this precise combination.

4 1 a a a a

Claims (7)

1. A pressure cap suction valve assembly comprising a suction valve body having an aperture therein, a polymeric seal having an integral spigot that clips through the aperture in the valve body to secure the seal to the valve body, a valve stem moulded in plastics in one piece to define a valve seat and a projecting shank that extends through the spigot in the seal and the aperture in the valve body, the valve stem being arranged to seat against the valve body, and a spring mounted on the shank to act between one end of the shank and the valve body to hold the valve seat and polymeric seal in sealed engagement against the valve body.

2. A pressure cap suction valve assembly according to Claim 1 wherein the location of the shank of the valve stem within the spigot of the seal defines a gap to allow passage of fluid.

3. A pressure cap suction valve assembly according to either Claim 1 or Claim 2 wherein the valve stem comprises a circular flange with the shank projecting centrally therefrom.

4. A pressure cap suction valve assembly according to Claim 3 wherein the valve seat is defined by an annular lobe provided on the underside of the circular flange. A pressure cap suction valve assembly according to any one of the preceding claims wherein the shank terminates in a head portion and the spring is located between the head portion and the underside of the valve body.

6. A pressure cap suction valve assembly according to any one of the preceding claims wherein the spigot of the polymeric seal is provided with a bulbous portion to allow the seal to clip within the aperture of the valve body like a grommet.

7. A radiator cap incorporating a pressure cap suction valve assembly according to any one of the preceding claims.

18. A pressure cap suction valve assembly substantially as described herein with reference to and as illustrated in Figures 2 to 4 of the accompanying drawings. DATED this 29th day of August, 1991. AUTOCAPS (AUST) PTY. LTD. By Its Patent Attorneys GRIFFITH HACK CO. Fellows Institute of Patent Attorneys of Australia. tel 4*4 C 4444,1 C 4 44 44 1*