WO1985005429A1

WO1985005429A1 - Straightway cock

Info

Publication number: WO1985005429A1
Application number: PCT/DK1985/000048
Authority: WO
Inventors: Hans Ole JO^/RGENSEN; Ole Dennis Lund Laugesen
Original assignee: Freses Metalsto^/Beri & Armaturfabrik A/S
Priority date: 1984-05-24
Filing date: 1985-05-21
Publication date: 1985-12-05
Also published as: EP0183741A1; DK254684D0; AU4407385A; DK254684A; DE3590222T1

Abstract

A straightway cock has a ball-shaped or cylindrical plug (2), which is pivotally located in a house (1). In the plug (2) there are provided a number of flow channels (9, 10), at least one of which joining a chamber (8) under the bottom of the plug (2), same chamber (8) being connected with a gate (11) so that communication from another gate (12) to the gate (11) is created, when the cock is in its open position. The plug (2) is so designed that between closed and open position the cock must substantially be turned 270o, and because of the chamber (8) this can be done without interjacent closing areas. Hereby a slow and gradual closing of the fluid flow is obtained, thus avoiding damaging water hammers in the piping system, as sudden closing of the cock is made impossible.

Description

STRAIGHTWAY COCK

The invention re_flates to a straightway cock with a ball-.shaped or cylindrical plug, same plug having two or more flow channels being connected with each other inside the plug, a housing with two gates, a- packing ring wedged in between the housing and the plug, a handle for turning the plug around the longitudinal axis of same, and possibly a hollow support part being especially adapted for the purpose of pressing the plug against the packing ring, and which is inserted in the housing on the side of the plug which is opposite to the packing ring.

Ball cocks are often used for the closing of pipes that lead for example to a drain cock, so that the pipe can be closed before the drain cock. Hereby it becomes possible to dismount or take apart the drain cock without fluid spillage. It will often be advantageous to use straightway cocks as in a simple manner these can be mounted to extend an exist¬ ing pipe.

The most common embodiment of such a closing cock is a straightway cock with a ball-shaped plug, through which a single drilling extends diametrically. Such a cock can be turned 90° between entirely open and closed position, and by turning the cock 180° from the closed position the cock will be closed again.

For the purpose of regulation cocks with several drillings are furthermore known, so that the fluid flow through the cock can be regulated evenly.

It has proved inexpedient to close a cock of the known kind too suddenly. If for example water flows through the cock and the cock is suddenly closed, a brief increase of pressure will arise in the piping system before the cock because of the inertia of the flowing water. This socalled water hammer can become up to twenty times as large as the pressure in the piping system prior to the closing. This water hammer may in certain cases be so powerful that it is able to damage the piping system or at worst burst it.

It is the object of the present invention to provide a straightway cock being so constructed that i_he water hammers mentioned above will not occur or that they only occur in a substantially reduced degree, and this is obtained by the fact that between its extreme positions the plug can substantially be turned 270°, that along substantially a quarter of its circum¬ ference the plug is provided with a closing area, that at least one of the flow channels joins the bottom of the plug, and that under the bottom of the plug there is a chamber, same chamber being connec¬ ted with the gate that is mounted on the side of the plug which is opposite to the packing ring.

As the plug has to be turned 270° from open to closed position, it becomes very difficult to close the cock with one single motion of the hand. Furthermore, as a turn of 270° takes more time than a turn of only 90°, it will thus take considerably more time to close the cock according to the invention than one of the known cocks. A sudden closing of the cock according to the invention is thus impossible, and consequently the extent of the water hammer will be reduced. To prevent the cock from being likewise closed in the position where the plug is turned 180° from the closed position, the fluid can in this posi¬ tion flow through the flow channel, which joins the chamber under the bottom of the plug, and through the chamber to the discharge gate, so that the closing of the cock can be effected by a turn of the plug of 270° without interjacent closing areas. Because of the design of the cock it thus becomes impossible to close same so suddenly that damaging water hammers may occur.

A cock according to the invention may as related to in claim 2 be characterized in that along the circumference of ^" the plug and outside the closing area there are provided a number of evenly distributed, radial flow channels with different cross sections, so that the cross section areas decrease from open towards closed position. Thus, a gradual closing of the fluid flow is obtained by turning the plug, so that any water hammers are further reduced.

As related to in claim 3 it may be advantageous that the plug on a cock according to the invention has one flow channel only at right angels to the axis of rotation, and that this flow channel is designed as a slit encircling the plug partly, the width of same slit decreasing from open towards closed position. Hereby, in a simple manner a gradual and very evenly proceeding closing of the fluid flow is obtained. A cock according to the invention may also as related to in claim 4 be characterized by radial, identical flow channels being so distributed that the distance between them is increased from open towards closed position. It is hereby obtained that all of the flow channels can be made by means of the same tool, advan¬ tageously by drilling.

It is advantageous as related to in claim 5 that the outer side of the housing is provided with one or more stop pieces working together with the handle. It can hereby be prevented that the cock is closed by a turn of only 90°, as the plug must be turned the determined interval of 270° between open and closed position.

By providing the handle with one or more protuding parts working together with the housing, as related to in claim 6, it can likewise be obtained that the lug must always be turned 270° between open and closed position.

In the following the invention will be further descri¬ bed with reference to the drawing, wherein

fig. 1 shows a longitudinal section through a cock according to the invention, where the plug is in totally open positi¬ on,

fig. 2 shows a sectional view through the cock from fig. 1 seen in the direction of the arrows along the line II-II, fig . 3 shows the cock from fig . 1 in closed position , and

fig. shows the cock from fig. 1 seen from above with the handle in different positions.

Fig. 1 shows a longitudinal section through an entirely open cock according to the invention. The cock consists of a housing 1 with two gates 11, 12. In the house

1 a substantially ball-shaped plug 2 is pivotally located. In the plug 2 there are provided four flow channels 9, 10, one flow channel 10 of which joining the bottom of the plug 2. The plug 2 is in a known manner secured to a handle 4 with a connection part, same connection part extending through a hole in the housing. 1 and by means of a packing ring 5 lying tightening against said housing. Between the plug

2 and the housing 1 a packing ring 3 is wedged in. This packing ring ensures that in closed position no fluid is able to get past the plug 2. In the housing

1 there is furthermore screwed in a hollow support part 6 in an internal thread, and under the plug

2 there is provided a chamber 8 which through the support part 6 is connected with the gate-11.

A flow channel 10 joins the bottom of the plug 2 so that when the cock is in its open position there is communication from the gate 12 to at least one of the flow channels 9 and further through the plug 2 to the flow channel 10, the chamber 8 and through the hollow support part 6 to the gate 11.

The flow channels 9 in the plug 2 can advantageously be made as drilled holes with decreasing diameter from open to closed position.

On the outer side of the housing 1 a stop piece 7 is located, same atop piece together with the handle 4 determining the turning angle. Because the rear part of the handle 4 can pass across the stop piece 7. By means of only one stop piece 7 a turning interval of 270° for the plug 2 is thus determined.

The hollow support part 6 is used in order to ensure that the plug 2 is pressed against the packing ring 3 in a proper manner.

Fig. 2 shows how the plug is provided with a closing area 13, and fig. 3 shows how in closed position this closing area 13 obstructs fluid passage through the cock.

In fig. 4 the reference number 4 indicates the position of the handle when the cock is entirely open. 4' ' indicates the position of the handle when the cock is closed, and position ¹ ' shows the cock in a positi¬ on lying between entirely open and closed. The figure shows how the rear part of the handle 4 can move across the stop piece 7 which is firmly fixed on the housing 1, just as it shows that the handle 4 and with it the plug 2 have to be moved 270° between its extreme positions.

Although the plug 2 on the drawing is shown with three radial flow channels 9 and one flow channel 10 in the bottom of the plug, it will be possible to vary the number of flow channels in a cock according to the invention in various ways, dependent on the purpose of application of the cock. For example one, slit-shaped, radial flow channel, or a large number of flow channels with small cross sections located in an advantageous pattern.

In certain applications it may furthermore be advan¬ tageous if the plug is cylindrical in stead of ball- shaped. It is also possible to locate the plug in other manners that do not require the use of the hollow support part.

Furthermore, it will be possible to determine the rotation of the plug of 270° in various manners. Beyond the manner shown in the figure it is also possible to provide the handle with a pin extending in a groove in the housing, thus determining the turning interval. The housing itself may in a known fashion be provided with thread stubs, welding ends or the like.

Claims

C L A I M S

1. Straightway cock with a ball-shaped or cylindrical plug, same plug having two or more flow channels being connected with each other inside the plug, a housing with two gates, a packing ring wedged in between the housing and the plug, a handle for turning the plug around the axis of rotation of same, and possibly a hollow support part being especially adapted for the purpose of pressing the plug against the packing ring, and which is inserted in the housing on the side of the plug which is opposite to the packing ring, c h a r a c t e r i z e d in that between its extreme positions the plug (2) can substan- tially be turned 270°, that the plug (2) along substantially a quarter of its circumference is provided with a closing area (13), that at least one of the flow channels (10) joins the bottom of the plug (2), and that under the bottom of the plug (2) there is provided a chamber (8), same being connected with the gate (11) which is mounted on the side of the plug (2) that is opposite to the packing ring (3) .

2. Cock according to claim 1, c h a r a c t e ¬ r i z e d in that along the circumference of the plug (2) and outside the closing area (13) there are provided a number of evenly distributed radial flow channels (9) with different cross sections, so that the cross section areas decrease from open towards closed position.

3. Cock according to claim 1, c h a r a c t e ¬ r i z e d in that the plug (2) has one flow channel only at right angles to the axis of rotation, and that this flow channel is designed as a slit which encircles the plug (2) partly, the width of same slit decreasing from open towards closed position.

4. Cock according to claim 1, c h a r a c t e ¬ r i z e d by radial identical flow channels being so distributed that the distance between same is increased from open towards closed position.

5. Cock according to claims 1, 2, 3 or 4, c h a ¬ r a c t e r i z e d in that the outer side of the housing (1) is provided with one or more stop pieces (7) working together with the handle (4) and thereby determining the interval between the extreme positions of the plug (2) .

6. Cock according to claims 1, 2, 3 or 4, c h a ¬ r a c t e r i z e d in that the handle (4) is provided with one or more protruding parts working together with the housing (1) and thereby determining the interval between the extreme positions of the plug.