GB2204100A - Hydrant - Google Patents

Abstract

A hydrant constituted by an elongated body 1 intended to be partly buried comprises a closure ring 9 upon which a seal 11 of the hydrant acts. Sealing is controlled from the top end of the hydrant by a transmission shaft 13 which moves axially to apply the seal against the closing ring. The transmission shaft comprises at its uppermost region, replacing the standard nut, a helical channel (20; Fig. 3) having wide pitch and hemispherical section. A cap 21 mounted to rotate freely in the body is provided on its side wall with a plurality of openings or housings (24; Fig. 2) for balls 25, the housings being frusto-conical so that the balls may enter them to engage the helical channel so that, by means of a small angular rotation of the actuating head a considerable axial displacement of the transmission shaft towards the closing ring is achieved with minimum effort thus converting the rotary movement of the cap into an axial movement of the shaft. A hydrant drain valve (Fig. 5) is also disclosed. <IMAGE>

Description

A HYDRANT DESCRIPTION OBJECT OF THE INVENTION The present invention relates to a hydrant of the type used in urban water supply installations, intended to be used basically as water offtake points for water tank cars of the types used for fire-fighting and cleansing services, usable also for sprinklers, a hydrant the specific structural characteristics of which have been designed abiding by the relevant legal standards, to achieve maximum ease and speed in the operations of opening and closure thereof.

BACIxGROUND TO TIEE INVENTION As is well known, hydrants are intended to be connected to an underground water supply network, so that part of same has to be buried, while another part protrudes from the ground, the appropriate water offtakes being arranged in the latter part, complemented by protective caps, the plunger sealing the hydrant being situated in the buried part of same, being actuatsble from the top end and through suitable transmission means.

More concretely, hydrants comprise a vertically elongated body in which said outflow openings are provided, there being associated to said body by means of straps and seals a lower barrel or body being.an axial extension of the former and intended to be partly buried, receiving for its part at its lower end the corresponding member for connection to the piping, whether such connection be horizontal or vertical, there being placed between said two members a closing ring on which the sealing plunger has to- act, fitted within the lower connection.

Axially integral with said sealing plunger is a transmission shaft which extends longitudinally along the hydrant as a whole and which has a threaded outermost and upper section, so that, by acting with the proper tool on a nut situated on the upper cover of the body, the rotation of said nut brings about the longitudinal displacement of the shaft either in an opening direction dr in a closing direction for the seal.

As a complement to this structure and in accordance with the legal standards in existence in this respect the lower barrel or body of the hydrant must comprise a perimetral weakening line which permits the breaking of same along this region when an impact of considerable force is exerted upon it, and ensuring the automatic closure of the seal under such circumstances, while the chamber defined above the seal must be assisted by a drain valve which opens automatically when said seal closes, permitting the draining of the hydrant and preventing the storage of residual water in same which could freeze under specific environmental temperature conditions causing the body of the hydrant to burst.

In accordance with this overall basic structuring conventional hydrants pose two basic problems. On the one hand, because of the dimensions of the seal, generally large due to the fact that when using hydrants a great flow of water is required so that operating the nut fitted on the upper end of the transmission shaft should not require excessive force, it is necessary that the thread of said threaded portion, as well as the complementary thread of the threaded section of the shaft, should be of very short pitch which, associated with the substantial distance which has to exist between the seal and the seating ring, in open position, means that this operation as well as the subsequent closing operation are extremely slow.

On the other hand, the solutions adopted as regards the drain valve of the hydrant are often of doubtful effectiveness, and in all cases structurally complex and costly.

DESCRIPTION OF TlB INVENTION The hydrant proposed by the invention has been perfected with a view to solving the problems set out hereinabove, yet retaining all the structural and operational requirements laid down by the standards in force in this field.

ore concretely, and to facilitate the actuation of the seal of same, it has been provided that the standard motwon transmission shåftshould comprise at its upper end, as a replacement for the standard threaded region, a section provided with helical grooving, of half groove section and great pitch, while the also standard nut fitted on the bonnet of the hydrant body has been replaced by a cap on the side wall of which a number of housings are provided for the respective balls which protrude substantially towards the inside of said cap, the said housings conforming to a frustoconical pattern to facilitate the coupling of the balls when assembling the device, said balls being fixed by an exterior envelope, though the diameter of the inner mouth of said openings being smaller than the diameter of said balls so that, even though they protrude substantially inside the cap, they cannot do so completely.

Obviously, said housings will be disposed on the side wall of the cap in conformity with the helical channel provided on the upper end of the transmission shaft, and the radius of curvature of said balls will coincide with the radius of curvature of said channel, so that said balls will act as means of transmission between the cap and the shaft for the axial displacement of the latter when the cap rotates, with minimum friction coefficient permitted by the great pitch for the helical channel to which reference was made hereinabove, a great pitch which in turn determines a considerable axial displacement of the shaft or, that which is the same, a considerable displacement of the seal of the hydrant for each turn imparted to the control cap, with the consequent reduction of the time required to perform the operations of opening or closure of the hydrant.

On the other hand, as another of the characteristics of the invention, it has been provided that the drain valve of the hydrant should be in the form of a bent orifice provided in the actual closure ring of the seal, in such a manner that the horizontal branch of said bent orifice should be open to the outside while the vertical branch extends downwards, passing right through said ring and receiving inside it a small seal with an upper expanded head supported by the corresponding gasket by means of which the closure is effected while its stem protrudes inwards and places itself in the path of the principal seal during the movement of the latter towards the closing position, the auxiliary seal corresponding to this drain valve tending towards a closure position as a result of the action of a spring, a state ol affairs obtainea n tile toe opening position for the principal seal, whereas, when the latter moves towards the closure position and more concretely in limit position, it impinges upon the stem of the secondary seal and brings about the inescapable opening of the drain valve.

DESCRIPTION OF THE DRAWINGS To complete the description which is being given and with a view to promoting a better understanding of the characteristics of the invention there are appended to the present descriptive memorandum, as an integral part of same, a set of drawings which, for the sake of illustration and non-limitatively, show the following;- Fig. 1 shows a side elevation and a section of a hydrant according to the improvements the subject of the present invention.

Fig. 2 shows a detail, also in side elevation, magnified and in section, of the actuation cap for the drive transmission shaft to the seal.

Fig. 3 shows again in side elevation and on a larger scale the top end of the transmission shaft.

Fig. 4 shows a plan view of the closure ring on which the principal seal acts and in which the drain valve is provided.

Fig. 5, finally, shows a detail in elevation and in cross-section of said closure ring, at the level of the housing for the drain valve.

PREFERRED EDEODDZNT OF THE INVENTION In the light of said figures it may be noted how the recommended hydrant is constituted as any conventional hydrant, from a body 1, generally cylindrical and extending vertically, in which, laterally and at the upper part, various outlets 2 are provided, fitted with corresponding protective caps 3, said body 1 being extended coaxially and below into a barrel 4, intended to be partly buried, said barrel 4 being fixed to the body 1 by means of the flange 5 and which, according to the standards in force, has a perimetral weakening line 6 which ensures the breaking of the hydrant along said line as a consequence of a possible impact upon same, the barrel 4 receiving at the bottom and by means of the flange 7, a lower connecting body 8 designed as in the example of practical embodiment shown in Fig.I for vertical connection, but which could similarly be also provided for horizontal connection, there being connected to the mouth of said lower body 8 a closure ring 9, on the seating 10 of which the principal seal 11 would act, actuated by means of a transmission shaft 13, constructed of two sections connected by means of a cap 14, with a weakening line 15, at the level of the breaking line 6, the lower section 13 of said shaft being of quadrangular or polygonal cross-section to prevent the rotation of said shaft, for which purpose the closure ring 9 comprises a diametrical arm 16 mith a central opening 17 to an identical pattern, concretely quadrangular in the example of practical embodiment represented on the figures, a shaft which is actuated from outside through the head 18 set up above the bonnet 19 which closes the body 1 at the top, using the proper tools.

Now, starting from this basic structure and will be observed particularly in Fig. 3, the invention is centered on the fact that the upper section 13' of the transmission shaft, concretely in its uppermost region, comprises a helical channel 20 of half groove section and wide pitch, replacing the standard threaded section, while, also and as a replacement for the standard nut, at the uppermost region of the body 1 and also fixed with the aid of the bonnet 19, there is provided a cap 21 which, as may also be seen in Fig. 2, in additipn to comprising the standard actuating head 18 and the also standard peripheral flange 22, for its fixing with the bonnet 19, and with the interposition of a seal 23, comprises a plurality of holes 24 with an outwardly divergent conical configuration, in which respective balls 25 are housed, the diameter of the inner mouth of the holes 24 being slightly less than the diameter of said balls so that the latter protrude partly inside the cap 21 but remain retained within the latter, as may be seen also in Fig. 2, while they have direct access, at the time of assembly, through the rear mouth of said openings or housings, being retained by a shell 26 which is fitted in a stepped relief of the cap 21, providing outer surface continuity with the latter, and which is taken up axially with the cooperation of the elastic ring 27.

As is obvious, and as was stated hereinabove, the housings 24 of the cap 21 and consequently the balls 25 will be distributed to correspond with the helical channel 20 of the shaft 13', as said balls have to move in this channel as may also be seen in Fig. 1.

In conformity with this arrangement the rotation of the cap 21 brings about an axial displacement of the shaft 13 in one or the other direction with the consequent movement of the seal 11, towards or away from the closure position, depending on the direction of rotation imparted to said cap 21, in response to an extremely rapid and simple actuation, rapid due to the wide pitch of the horizontal channel 21, and simple in that said ball-based transmission system assumes a minimum friction coefficient which permits such displacement with an effort which is also minimum.

Complementarily, as as another of the characteristics of the invention, the hydrant drain valve which has to open immediately after the closure of the principal seal 11 is mounted in the actual closure ring 9, for which purpose the latter, and in its diametrical arm 18, has a cylindrical expanded region 28 in which there is provided an orifice parallel with the shaft with three sectors 29-29'-29n of different diameters, decreasing progressively upwards, the intermediate sector 29 being extended by a radial and lateral outlet 30 constituting the water drainage outlet.

Housed in the sector 29 is a sealing head 31, supported by the corresponding seal 32, while in sectors 29" and '29" a stem 33 is housed the diameter of which is considerably smaller than that of the intermediate sector 29', as a result of which, in an opening situation of the sealing head 31, the water flows through the annular chamber delimited between the wall of sector 29' and the stem 33, while the diameter of said stem adapts itself substantially to the bottom sector 29", said stem extending further below the closure ring 9,, concretely beyond its cylindrical expanded region 28 to receive coaxially a spring 34 which rests on the mouth of the orifice 29n and on a nut 35 fitted on the free end of said stem, and end which, as may again be seen in Fig. 1, is situated in a position facing the principal seal 11, so that in a closing position of the latter it impinges upon said stem 33, bringing about the lifting of the sealing head 31 to the opening position, and the subsequent opening of the valve for draining the hydrant, while when the latter is in actual use, i.e. when the principal seal 11 is in the open position, the spring 34 compels the stem 33, and consequently the sealing head 31, to move towards the closure position.

As a complement to the structure described, between the closure ring 9 and the region corresponding to the wall of the lower body 8, there is provided an annular chamber 36 in communication with the outside through openings 37 provided in said wall.

In this way a drain valve is obtained for the hydrant, extremely simple in structural terms, and the operational efficiency of which is ensured indefinitely without the slightest danger in this respect to the hydrant, as a possible failure of said valve might mean its deficient closure, but in any event the valve would assume the open position with the principal seal of the hydrant in closure position, and, consequently, the draining of the hydrant is assured in all circumstances.

Claims (5)

CLAYS

1. An improved hydrant of the type of hydrants constituted by means of an elongated body intended to be partly buried, at the top region of which side outlets are provided supported by the corresponding protective covers, and at the bottom end of which a member is fitted for connection to the water supply network, said connection body comprising at the top a closure ring upon which the seal of the hydrant acts operated from the top end of the hydrant by means of a transmission shaff which receives movement from a head which protrudes through the top cover of the body and which permits the application of a suitable tool, essentially characterised in that said transmission shaft comprises at its uppermost region and replacing the standard nut a helical channel with wide pitch and hemispherical section, while, associated with the outer actuating head, provision is made for a cap mounted able to rotate freely in the body and provided on its side wall with a plurality of openings or housings for the respective balls, with the particular feature that said housings are frusto-conical so that the balls may have direct access to said housings from outside the cap and substantially enter it to become joined in the helical channel of the upper end of the shaft, all of which so that, by means of an angular rotation of the actuating head, of small amplitude, a considerable axial displacement of the transmission shaft towards the seal is achieved, all of this being achieved with a minimum effort originating from the set of balls constituting the elements which convert the rotary movement of the cap into an axial movement of the shaft.

2. An improved hydrant according to Claim 1, characterised in that the helical channel at the top end of the shaft has a curvature coinciding with that of the set of balls, and in that the housings of the cap in which said balls rotate have an outer diameter substantially greater than that of the latter, and an inner diameter slightly smaller to prevent their full access to the inside of the cap, it having been provided that said balls should be retained in their housings, in their tendency to move outwards, by an envelope which is fitted in a recessed section of the cap and which is held axially over the latter with the aid of a pressure ring.

3. An improved hydrant according to Claim 1, characterised in that the drain valve for the hydrant in an inoperative state of the latter is fitted in the actual closure ring on which the principal seal is seated, said closure ring being fitted with a diametrical arm in which there is provided centrally an orifice of polygonal section for the passage of the transmission shaft, itself also of polygonal cross-section in this area, there being fitted laterally in said diametrical arm a cylindrical thickened portion with, passing vertically through it, an opening with three progressively decreasing diameters, there emerging laterally from the part of intermediate diameter an opening for the outflow or discharge of water, while, in said vertical opening and more specifically at the upper region of greatest diameter, a head operates fitted with the corresponding seal, while in the other two regions a stem acts which isextended towards the principal seal and actuatable by the latter in a closure situation, more specifically against a spring fitted coaxially over said stem and which tends to move the latter in a closure direction for its sealing head, a spring against the tension of which said stem is moved by the principal seal during the forward movement for the closure situation of the latter.

4. A hydrant substantially as hereinbefore described with reference to the accompanying drawings.

5. The hereinbefore described invention in all its new and useful aspects.