GB2071819A - Fluid shutoff cock for the internal heating circuit of motor vehicles - Google Patents

Abstract

A fluid shutoff cock for the internal heating circuit of motor vehicles, comprises body (1) with at least one inlet conduit (9) and one outlet conduit (7), a port (14) providing communication between said two conduits (9, 7), and a closure element (17) movable by means (45) for operation from the outside. The cock comprises connection means in the form of a pin and slot (31, 32) disposed between said operating means (45) and said closure element (17), in order to convert a rotary movement of said operating means (45) into a rectilinear movement of said closure elment (17). A spring hinged sleeve (26) presses the gate (17) against an O ring seal (16). <IMAGE>

Description

SPECIFICATION Fluid shutoff cock for the internal heating circuit of motor vehicles This invention relates to a fluid shutoff cock for the internal heating circuit of motor vehicles. Such cocks are generally connected between an engine outlet for the hot cooling liquid and the inlet of a radiator which is grazed by the air reaching the interior of the motor vehicle.

Known cocks in use at the present time comprise an inlet conduit and an outlet conduit which are in communication with each other inside the cock body by way of a port which is conveniently closed or partly closed by a disc. This disc is constructed in the most varied forms, for example in the form of a blade, or a plate, and the movement applicable to said disc can be one of rotation or translation. In this respect, an operating element, generally a control stem or pin projecting from the cock, is rigidly connected to said disc, and is operated by means of levers or tie rods from the vehicle interior, generally by means of a lever or knob disposed in proximity to the dashboard.

In such cocks, the direction of movement of the disc is parallel to the plane of the port in order to reduce the force on the control lever or knob during the adjustment of the cock.

However, cocks in which the drive element and thus the disc connected thereto translate have the drawback of requiring a relatively high operating force in order to ensure a perfect seal about the control stem during its translation. In embodiments in which the operating element is a pin and is therefore operated by rotation, this operating force is less because the resistance to the rotational movement by the seal gasket about said pin is less, however because of the rotational move ment which the connected disc makes, the cock has to be of relatively large overall dimensions.

The object of the present invention is to provide a fluid shutoff cock for the internal heating circuit of motor vehicles, which requires a relatively minimum operating force, and which at the same time is of relatively small overall external dimensions, so as to obviate the described drawbacks of cocks of known type.

Further objects and advantages of the cock of the present inevention will be apparent from the description given hereinafter.

The present invention provides a fluid shutoff cock for the internal heating circuit of motor vehicles, comprising an external body with at ieast one inlet conduit and one outlet conduit for the fluid, a port inside said body and providing communication between said conduits, and a closure and partial closure element for said port and movable by means for operation from the outside, characterised by comprising connection means disposed between said means for operation from the outside and said closure and partial closure element for said port, in order to convert a rotary movement of said means for operation from the outside into a rectilinear movement of said closure and partial closure element.

The present invention will be more apparent from the description of one embodiment thereof given hereinafter by way of non-limiting example with reference to the accompanying drawings, in which: Figure 1 is a partly sectional side view of the cock embodying the present invention; Figure 2 is a section on the plane ll-ll of the cock of Fig. 1; and Figure 3 is a section on the plane Ill-Ill of the cock of Fig. 2.

With reference to Figs. 1 to 3, a cock embodying the present invention comprises an external body 1 constructed completely of plastics material, and constituted by two half shells 2 and 3 conveniently produced by moulding, and joined together in a hermetically sealed manner along their perimetral edge 4 by means of hot welding, for example of the hot blade type, so as to define a cavity 5 inside the body 1. Internal to the perimetral edge 4 and parallel thereto, the half shell 3 comprises a perimetral collar 6, on the upper edge of which there rests the inner surface of the half shell 2 during the welding stage, and of which the purpose is to define the inner height of the cavity 5.Said half shells 2 and 3 are of substantially triangular shape, and from their plane there branch, respectively, an outler conduit 7 from which a further conduit 8 branches, and an inlet conduit 9 which at is end comprises a flange 10 with two bores 1 2 for fixing the cock.The outlet conduit 7 is in communication with the cavity 5 by way of a port 1 4 about which, in the half shell 2, there is formed an annular cavity 1 5 in which an annular gasket is housed to form a seal against a closure and partial closure element 1 7, constituted by a flat plate of substantially rectangular cross-section, comprising a terminal curved edge 1 8 which mates with a curved base wall 1 9 of the perimetral collar 6, and comprising at its other end a curved corner 20 which mates with a curved part 21 of the perimetral collar 6.Said perimetral collar 6 also comprises two parallel side walls 22, spaced apart by a distance slightly greater than the minor side of the element 17, so as to constitute guide walls for the translatory movement of the element 17, as described hereinafter. Said closure and partial closure element 1 7 is conveniently constructed of plastics, and has a through aperture 24 of circular cross-section, the diameter of which is substantially equal to the diameter of the port 14, and of which the edges are substantially superposed on those of the port 14 when said element 1 7 is disposed in the position of maximum opening of the cock, as shown in Figs. 2 and 3.

The inlet conduit 9 opens into the cavity 5 by way of a compartment 25 of greater crosssection, and in which there is housed a tube 26 having an inner diameter substantially equal both to the inner diameter of the conduit 9, and to the diameter of the through aperture 24 of the element 1 7. Said tube 26 has an outer perimetral collar 27 on which there rests one end of a cylindrical spring 28, the other end of which rests on an annular step 29 provided in the compartment 25. The tube 26 is thus urged by the spring 28 against the closure and partial element 1 7, which becomes urged against the annular gasket 16.

In the element 1 7 towards the end thereof in proximity to the curved corner 30, there is provided a slot 31 which houses a pin 32 branching, perpendicular to the plane of the element 1 7, from one end of a flat part 33 which is parallel to the plane of the element 1 7 and branches from a cylindrical member 34, which also has its axis perpendicular to the plane of the element 17. Said member 34, the flat part 33 and the pin 32, are constructed in a single piece, conveniently by moulding plastics material, and constitue overall a member for operating the cock from the outside, in that the member 34 is housed in a cylindrical cavity 35 provided in the half shell 3 and open outwards.An annular step 36 is also provided in the half shell 3 about said cavity 35, and houses a perimetral gasket 37 which seals the cavity 5 about the cylindrical member 34. The pin 32 has a circular section of diameter slightly less than the width of the slot 31, and also comprises a head 40 of elliptical section, the minor axis of which is substantially equal to the diameter of the pin 32, and thus slightly less than the width of the slot 31, whereas its major axis is greater than the diameter of the pin 32 and thus greater than the width of the slot 31, but less than the length of the slot 31 in order to allow the element 1 7 to be mounted on the pin 32 in a predetermined position, and to alow subsequent relative movement of the pin 32 in the slot 31, without the possibility of withdrawal.

As can also be seen in Fig. 3, the height of the pin 32 is greater than the height of the slot 31, to allow movement of the element 1 7 along the axis of.the pin 32, to give better operation as described hereinafter. The perimetral collar 6 also comprises two walls 41 and 42 (Fig. 2) which serve as a limit stop for the flat part 33 of the means for operation from the outside. At that end thereof which is external to the body 1, said cylindrical member 34 comprises a threaded bore 43 into which a screw 44 is screwed in order to lock on to the member 34 a member 45 of known type comprising two opposing arms to which are connected the ends of the control rods (not shown), which also rest on a member 46 of known type branching from and integral with the surface of the conduit 9.

The operation of the described cock embodying the present invention is as follows.

The cock embodying the invention is generally disposed upstream of a radiator for heating the interior of a motor vehicle. and is traversed by the hot engine cooling liquid from the engine outlet. The member 45 and thus the cylinndrical member 34 are rotated by means of a control element (not shown), so that the pin 32 rotates about the axis of the cylindrical member 34.There is a corresponding sliding of the pin 32 in the slot 31, with a consequent rectilinear translation òf the closure and partial closure element 1 7. In the position illustrated in Figs. 2 and 3, the cock is in its maximum opening position. in that the through aperture 24 of the element 1 7 corresponds with the port 14, rotation of the cylindrical member 34 then causing progressive closure of said communication between the inlet conduit 9 and outlet conduit 7r until when in the position indicated by dashed lines in Fig. 2, the flat part 33 stops against the wall 42 of the perimetral collar 6 and the element 1 7 assumes a position such that the through aperture 24 is completely outside the area within the annular gasket 16.

The cock embodying the present invention offers various advantages. Firstly, the operating force for the cock is relatively small, because the cylindrical member 34 rotates relative to the gasket 37, which is required to seal the internal cavity 5 of the body 1 against the outside. The overall size of the body 1 is at the same time very small, in that the closure and partial closure element 1 7 is moved with a rectilinear movement. This is provided by the fact that the pin 32 is coupled by being housed in the slot 31. The arc of rotation of the pin 32 and the length of the slot 31 can be conveniently chosen so that during the operation of the cock, the pin 32 only slides in the slot 31, without rubbing.

By constructing the means for operation from the outside (i.e. the member 34, flat part 33 and pin 32) separately from the closure and partial closure element 17, the cock seal is made more reliable in that because the element 1 7 can slide along the axis of the pin 32, perfect sealing of the annular gasket 1 6 on the element 1 7 is always ensured, even in the presence of thermal deformation, localised fluid pressure, unbalanced operating forces etc. The closure and partial closure element 1 7 is urged against the gasket 1 6 by the tube 26 under the action of the spring 28.The tube 26 also has the advantage of providing a substantially constant section between the inlet conduit 9 and through aperture 24, so as to ensure maximum throughput of the cock.

The whole structure of the cock, which is completely of plastics construction, is relatively simple and economical, and this is also valid for the connection between the two half shells 2 and 3, which is made by hot blade welding, and the perimetral collar 6 which constitutes the support for the half shell 2 defines a constant height for the cavity 5, which is however small, and of relatively small dimensions, to prevent a substantial pressure drop through the cock.

Finally, it is apparent that modifications can be made to the embodiment described and illustrated, without leaving the scope of the inventive idea. For example, the section of the through aperture 24 of the closure element 1 7 can be of a convenient profile in order to determine a required relationship between the angle of rotation of the member 45 and the cock throughput.

Claims (11)

1. A fluid shutoff cock for the internal heating circuit of motor vehicles, comprising an external body with at least one inlet conduit and one outlet conduit for the fluid, a port inside said body and providing communication between said two conduits, and a closure and partial closure element for said port and movable by means for operation from the outside, characterised by comprising connection means disposed between said means for operation from the outside and said closure and partial closure element for said port, in order to convert a rotary movement of said means for operation from the outside into a rectilinear movement of said closure and partial closure element.

2. A cock as claimed in claim 1, characterised in that said connection means comprise a pin arranged to slide in a slot, these pertaining to said means for operation from the outside and to said closure and partial closure element respectively, or vice versa.

3. A cock as claimed in claim 2, characterised in that said closure and partial closure element is able to slide to a certain extent relative to said means for operation from the outside, in the direction of the axis of said pin.

4. A cock as claimed in claim 3, characterised in that the axis of said pin is perpendicular to the surface of said closure and partial closure element.

5. A cock as claimed in one of claims 2 to 4, characterised in that said pin comprises a stop head, the cross-section of which is contained within said slot in order to allow said closure and partial closure member to be demounted.

6. A cock as claimed in one of the preceding claims, characterised in that said external body internally comprises guide walls for said rectilinear movement of said closure and partial closure element.

7. A cock as claimed in one of the preceding claims, characterised in that said external body comprises, about said port, a compartment for housing an annular seal gasket for said port, said annular seal gasket resting on said closure and partial closure element.

8. A cock as claimed in one of'the preceding claims, characterised in that said closure element comprises a through aperture for opening, partly closing and closing communication between said port and the interior of said body.

9. A cock as claimed in claim 8 and dependent on claim 7, characterised in that a tube is housed in said external body to provide a substantially constant cross-section or a linear variation in cross-section between said through aperture and one of said conduits, said tube being urged by resilient means against said closure and partial closure element on the opposite side to that on which said annular seal gasket rests.

10. A cock as claimed in one of the preceding claims, characterised in that said closure and partial closure element and said connection means are housed inside said external body, and that said means for operation from the outside pass through said external body in a zone which opens towards the inside, in said zone there being housed an annular gasket providing a seal against said means for operation from the outside.

11. A cock as claimed in one of the preceding claims, characterised in that said external body is constructed in the form of two half shells of plastics material, said half shells being connected together in a sealed manner along their perimeter by hot blade welding, and being provided internally with projections for determining their internal distance apart.

1 2. A fluid shutoff cock for the internal heating circuit of motor vehicles, as described with reference to the accompanying drawings.