This invention relates to an improved safety device for use in the removing of caps from the radiators of cooling systems of internal combustion engines, such as those employed in motor vehicles, tractors and the like.

Technical Field

Such caps, generally known as radiator caps, are removably attached to the header tanks or to overflow tanks of the cooling systems of internal combustion engines so that the coolant can be contained within the system under pressure. Because of the difficulties that arise by reason of the hot coolant and the pressure, radiator caps are formed with a particular type of bayonet fitting so that the cap can be removed to inspect the level of cooling fluid within the radiator and to replenish the fluid if required.

Background Art

Generally such caps are removed by firstly partly rotating the cap in an anti-clockwise direction in order that the pressure within the radiator system of the internal combustion engine can be relieved and then when the pressure within the radiator is substantially equalized with ambient pressure the cap can be turned further in an anti-clockwise direction and fully removed.

Because the cooling systems of internal combustion engines are generally pressurized, a danger exists in removing the cap from the radiator which forms part of the cooling system in that unless particular precautions are used, the sudden equalization of pressure between the interior of the cooling system and the ambient air can result in air and/or hot coolant exiting with force through the radiator opening. If there is a malfunction in the engine so that the coolant becomes overheated then an even more dangerous situation can occur even with the careful removal of the radiator cap because the pressure build up can be sufficiently high that when the cap is removed steam and/or hot coolant can be forced out of the opening under considerable pressure.

It is therefore an object of this invention to provide a means that can be used to facilitate the removal of radiator caps from the cooling systems of internal combustion engines which will alleviate or at least partly alleviate the above problem.

Disclosure of the Invention

Accordingly one form of the invention may be said to comprise a device to facilitate the removal of the cap from the radiator of the cooling system of an internal combustion engine, said device comprising an elongated tubular housing closed at one end,

a shaft extending through said closed end of the housing and having a reciprocal movement in relation to the longitudinal axis of said housing,

and a diaphragm secured to said shaft to have rotatory movement within said housing and having means to engage the said cap;

the construction and arrangement being such that the open end of the housing may be placed over the cap to be removed and the shaft operated to move the diaphragm longitudinally through the housing to contact and engage the said radiator cap and the said shaft may be rotated to rotate the said diaphragm to remove the said cap from the cooling system.

Preferably the diaphragm has a primary cavity to engage over the radiator cap and also has sockets to receive ears projecting from the cap.

Preferably the diaphragm includes a secondary cavity of a lesser dimension than the first cavity, with the secondary cavity having secondary sockets to receive ears projecting from said cap.

Preferably the diaphragm has a floor which extends circumferentially from the shaft to which the floor is secured, with the floor terminating in a circumferential skirt.

Preferably the periphery of the skirt includes at least two socket nodes each of which extends radially from the periphery of said floor.

Preferably each socket node includes a socket which is shaped to receive an ear projecting from the cap.

Preferably each socket node is substantially diametrically opposite the other socket node.

Preferably the diaphragm includes a lug node extending radially from the skirt.

Preferably the diaphragm includes two lug nodes each of which extends radially from the skirt.

Preferably the two lug nodes are positioned substantially diametrically opposite each other.

Preferably relief holes are formed between said skirt and the interior of said housing.

Preferably a compression spring acts on the shaft to yieldingly resist further travel of the shaft after the shaft has moved a predetermined distance into the housing.

Brief Description of Drawings

Preferred forms of the invention will now be described with the aid of the accompanying drawings wherein:

Fig. 1 is a partly cut-away view from below of an assembled unit;

Fig. 2 is a sectioned elevational view of the device;

Fig. 3a is a view of the device from below; and

Fig. 3b is a partly sectioned side elevational view of part of the device.

Best Mode of Carrying Out the Invention

Referring to the drawings, the device has a tubular housing 1 which in the highly preferred form may be cylindrical as shown and which may be formed of a suitable plastics material which is able to withstand the stresses of use and the temperatures that will be involved during use. Preferably, but not necessarily the material .forming the housing 1 is transparent or translucent. A handle 2 is attached to the side wall of the housing 1 and one preferred form of a handle is shown in Fig. 1. The housing includes a lid 3 which may be integrally formed with the housing as indicated or it can be formed so that it is removable, with suitable means being provided to maintain the lid on the walls of the housing.

The axial centre of the housing is provided with an enlargement 4 which has a bore 5 as shown more particularly in Fig. 2. A shaft 6 extends through the bore 5 with sufficient clearance being allowed between the shaft 6 and the bore, so that the shaft can have a reciprocal up and down sliding movement within the bore. The upper end of the shaft 6 is formed into a handle such as that indicated at 7. A compression spring 8 may be engaged on the shaft 6 so that the shaft 6 will be urged upwardly after the shaft has penetrated a predetermined distance into the interior of the housing 1.

The shaft 1 may be formed of any suitable metal which is preferably either non- corrodible or treated with a non-corrodible surface treatment. The lower end of the shaft is suitably attached such as by welding or the like to a diaphragm 10. In a highly preferred form, the device comprises a disc having a boss 11 into which the shaft 6 can engage and be secured. The disc also comprises a floor 12 which extends circumferentially from the boss 11. The periphery of the disc is provided with a skirt 13 from which a pair of radial socket nodes 14 and a pair of radial lug nodes 15 project. Preferably the socket nodes 14 are diametrically opposite each other and the lug nodes 15 are also diametrically opposite each other with the socket nodes 14 and the lug nodes 15 being equidistantly spaced around the circumference of the skirt 13 of the disc. The socket nodes 14 each have a primary socket 17 formed as indicated in the drawings with the sockets being of a size and shape that a radiator cap (not shown in the drawings) can

be engaged in the area bounded by the skirt 13 and with the ears that are normally provided on the radiator cap engaging in the primary sockets 17 of the socket nodes 14.

In order that the diaphragm can accommodate various sizes and formations of radiator cap, the device 10 is preferably also formed with a secondary depression 20 which has secondary sockets 21. The junction of the primary cavity and the secondary cavity 20 is bounded by a land 24 to provide a positive delineation between the primary depression and the secondary depression 20 and thereby facilitate the accommodation of different sizes of radiator caps.

The lug nodes 15 are provided to enable radiator caps to be removed which do not have radially projecting ears but which have flanges which project axially from the surface of the cap. In this instance, the lug nodes will engage against the axially projecting flanges as will be hereinafter further explained. r

To use the device, the open end of the housing 1 is placed over the radiator cap and downwards pressure is then applied on the handle 7 so that the diaphragm 10 will contact the radiator cap. Before the device 10 can contact the radiator cap, it is necessary to push the handle 7 downwardly against the pressure of the spring 8. This will assist in providing a more positive feel to the action and will therefore assist in the removal of the radiator cap. A typical radiator cap will have ears projecting radially out from the cap and the diaphragm can be moved so it will engage of the cap which will enter the primary depression. If the radiator cap is of a size that it cannot move into the secondary depression, upon rotating the handle 7 in an anticlockwise manner, the ears of the radiator cap will enter the primary sockets 17 of the radial socket nodes 13. Upon applying further rotational pressure to the handle 7 the radiator cap can be unscrewed to its first position. When the air/coolant pressure within the radiator has been equalised with the ambient air, the radiator cap can be unscrewed by further rotation of the handle 7. If a dangerous condition should arise such as there being excess pressure within the cooling system then any steam and/or coolant that may exit from the cooling system will enter the housing from below the radiator cap removing device 10 and will thus be deflected downwardly. Because the skirt of the radiator cap removing device includes radially

extending nodes 14 and 15, a relief holes 26 are formed between the skirt and the interior of the wall of the housing 1. Consequently a portion of any steam and/or coolant which may be discharged from the radiator system under pressure will pass through the relief holes 26 into the housing above the diaphragm 10 and this will assist in the dispersion of the excess pressure from the cooling system.

The form of the device shown in the drawings enables the device to be utilized with different sizes of radiator caps. Radiator caps of the larger size will generally be able to be engaged in the primary depression 18 and the ears of the cap can be entered into the primary sockets 17 of the socket nodes 14. Caps of smaller dimensions will be accommodated in the secondary depression and the ears of the cap can engage in the secondary sockets 21.

While in the forgoing description, it is disclosed that the highly preferred form of the invention includes both a primary and a secondary depressions with associated sockets in a more basic form, the diaphragm 10 may be formed with a single depression only. In addition, in the highly preferred form, the invention includes primary sockets 18 in the socket nodes 14 which are positioned approximately diametrically opposite each other, the invention also contemplates the incorporation of more than two primary sockets which may or may not be diametrically opposite each other.

Modifications and improvements to the preferred forms of the invention disclosed and described herein may occur to those skilled in the art and who come to understand the principles and precepts of the invention. Accordingly the scope of the patent to be issued herein shall not be limited solely to the embodiments of the invention set forth herein, but instead should be limited only by the advance by which the invention has promoted the art as defined in the appended claims.