EP0118630A1

EP0118630A1 - Extendable and retractable sprinkler device

Info

Publication number: EP0118630A1
Application number: EP83301325A
Authority: EP
Inventors: Shalom Jackerson
Original assignee: Ben Gurion University of the Negev Research and Development Authority Ltd
Current assignee: Ben Gurion University of the Negev Research and Development Authority Ltd
Priority date: 1979-04-11
Filing date: 1983-03-10
Publication date: 1984-09-19
Also published as: ZA831472B; IL57055A0; AU1230783A

Abstract

There is provided a disappearing sprinkler device connectable to a water supply line. The sprinkler device comprises a housing (2) of an elongated cross-section open at its top, and a pair of telescoping, tubular members (8,10). The first member (8) is stationary and the second member (10) is upwardly extendable by application of water pressure and downwardly retractable when the water pressure is reduced to below a given threshold. The housing is provided with a cover plate (18) which is fixedly attached to the sprinkler (16). The device also comprises a cam-like member (26) co-acting with guide means (22) to such effect that when the water pressure is reduced to below a given threshold the upwardly extended second member carrying the sprinkler is retracted. The rotary sprinkler, prior to its complete re-entry into the housing and regardless of its angular position at the instant the water pressure was reduced, is automatically oriented to assume an angular position of alignment with the elongated cross-section of the housing so that, upon further retraction, it will freely enter the housing.

Description

The present invention relates to a disappearing sprinkler device using rotary sprinklers of the percussion, or reaction, or any other rotary type.
"Disappearing" sprinklers, also called pop-up , sprinklers, which, in the non-operative state, are located below the surface of the ground and, upon being turned on, automatically rise to a certain height above ground, are known. Being turned off again, they "disappear" in the ground. Such sprinklers are most useful especially for lawns in parks, gardens, sports grounds, golf courses and the like, where protruding pipes or irrigation devices would constitute a nuisance, if not a safety hazard.
Disappearing sprinklers of this sort are known. They consist of a cylindrical, pot-like housing buried in, and flush with, the ground, and a rotary-type sprinkler rising from this pot-like housing when operating, and being retracted into the housing when water pressure is cut off. A major disadvantage of these disappearing sprinklers is the fact that the housing has to be cylindrical and of a diameter somewhat larger than the longitudinal extent of the sprinkler, as the latter, when retracting, has to fit the housing in all possible angular positions. The large cylindrical housings and circular covers required not only constitute a waste of material - about 80% of the available space remains unused after retraction of the sprinkler - and necessitate the use of larger injection machines, if made of plastics, but the large, bald patches formed by the cover are also unsightly and the covers themselves often unsafe and easy to vandalize.
In recognition of this fact, Tropeano et al (U.S. Pat. 2,989,247; 3,063,645 and 3,086,714) have proposed a number of pop-up sprinkler embodiments in which relatively long rotary sprinkling nozzles can be accommodated in relatively narrow housings by using guide mechanisms whereby, upon water pressure being cut off, the elongated nozzle is guided into a position of register or alignment with the narrow housing before entering same.
However, the devices claimed in these patents (the second and third of which are continuations-in-part of the respectively preceding patent) suffer from a number of serious drawbacks which are liable to greatly impair their effectiveness and usefulness: during the final stage of retraction. the sprinkler is not positively guided and the cover plate (36,10), fixed to the sprinkler top, is thus liable to be sufficiently out of alignment with the housing top to prevent proper closing. Even in the last of the three patents (3,086,714) which claims an improved guide mechanism, the camming surfaces 31 of the member 30 have left the guide surfaces 38, 38a, 40, 40a when the cover plate is still at an appreciable distance (20-25 mm) from the housing top and the sprinkler is no longer under any constraint. At this stage anything may cause the sprinkler body, although already inside the housing, to swivel 4-5⁰, which the housing will easily accommodate. Such an angular displacement will, however, definitely prevent the elongated cover plate from dropping into its seating in the housing top.
Another drawback of these prior-art sprinklers resides in the fact that no provision is made to prevent the inner telescoping tube (18, 20) tu be dragged along by the sprinkler to take part, to a greater or lesser degree, in the rotary stepping motion of the latter. This would impair the uniformity of irrigation, as the mostly haphazard dragging motion of the tube would be superposed on the uniform rotary motion of the sprinkler.
The most serious disadvantage of these prior-art sprinklers is, however, the fact that none of them is suitable for use with what is known as "adjustable angular sweep" percussion sprinklers which are widely used today. To be suitable for this type of sprinkler, the device must fulfil two conditions:

1) The sprinkler must always be returned to the housing in the same angular position. This condition is fulfilled by the devices of patents 2,989,247 and 3,063,645, but not of patent 3,086,714, in which the sprinkler will assume either of two different nesting positions, spaced apart by 180°, depending on the sprinkler position at the instant water pressure is cut off.
2) The aligning motion produced by the cam-like member must be in a sense opposite to the sense in which the sprinkler, upon stopping, is displaced from its proper nesting alignment. Thus, if the sprinkler is misaligned in the clockwise sense, the aligning motion must be counterclockwise, and vice versa. This essential condition is fulfilled by neither of the two devices that meet condition 1. In both, the aligning motion produced by the helical cam can be in one sense only - in the particular embodiments shown, in the counterclockwise sense.

It is one of the objects of the invention to overcome the above difficulties and disadvantages of the prior-art devices and to provide a disappearing sprinkler device, the housing of which is of a horizontal cross section not determined by the radius of the circle circumscribing the sprinkler, but by a geometric figure larger in longitudinal extent than in width, such as a narrow rectangle or ellipse or the like, by which the sprinkler, in plan view, is circumscribable. For a sprinkler circumscribable by a rectangle of, e.g., 12 x 3 cm, the surface area of the cover would be about 44 cm (given a wall thickness of the housing of about 2.5 mm), while the surface area of the cover of a cylindrical housing for the same sprinkler would be about 133 cm², that is, 300% larger. The larger the sprinklers used, the larger the savings realizable by the use of the device according to the invention. It is a further object of the present invention to facilitate the use, with pop-up devices, also of adjustable angular sweep percussion sprinklers.
These objects the invention achieves by providing -a disappearing sprinkler device connectable to a water supply line, comprising a housing of an elongated cross section, which housing is open at least at its top; a pair of telescoping, tubular members, a first member which is stationary, and a second member which is upwardly extendable by application of water pressure and downwardly retractable upon said water pressure being reduced to below a given threshold; a rotary sprinkler of the type which, in plan view, is circumscribable by a geometric figure larger in longitudinal extent than in width, which sprinkler is rotatably attachable to said second tubular member and assumes in the retracted state of said second member a non-operative position within said housing and, in the extended state of said second member, an operative position without said housing, a cover plate for said housing, which cover plate is fixedly attached to the top of said sprinkler and has a shape substantially fitting the top of said housing and, in said retracted state, covering said top, further comprising a cam-like member coacting with guide means to such effect that, when said water pressure is reduced to below a given threshold. causing said upwardly extended second member carrying said sprinkler to be retracted, said rotary sprinkler, prior to its complete re-entry into said housing and regardless of its angular position at the instant said water pressure was thus reduced, is automatically oriented to assume an angular position of alignment with the elongated cross section of said housing so that, upon further retraction, it will freely enter said housing, said cam-like member being provided with register means which, in conjunction with said guide means, accurately and positively define the angular position of said cover plate relative to said housing top during said further retraction.
While the invention will now be described in connection with certain preferred embodiments, it will be understood that it is not intended to limit the invention to these particular embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalent arrangements as may be included within the scope of the invention as defined by the appended claims.
In the drawings:

Fig. 1 is a cross,sectional view of a first embodiment of the device according to the invention;
Fig. 2 is a partial perspective view of the upper part of the housing, including part of the cover plate;
Fig. 3 shows part of the rear wall of the housing of Fig. 2, with a guide pin instead of the guide rail of Fig. 2;
Figs. 4 to 6 are perspective views, as seen from below, of several embodiments of the cam-like member;
Fig. 7 shows the device according to the invention in the retracted non-operative state;
Fig. 8 shows the device according to the invention in the extended, operative state,
Fig. 9 shows a partly cross-sectional view of second embodiment of the device according to the invention, in which the cam-like member is fixedly attached to the inner member of the telescoping pair;
Fig. 10 is a front view, in partial cro.s section, of the cam-like member of the embodiment of Fig. 9;
Fig. 11 is a partly cross-sectional view of a third embodiment of the device, in which the cam-like member is rigidly attached to the upper end of the outer member;
Fig. 12 is a top view (with the cover removed) of the embodiment of Fig. 11;
Fig. 13 is a side view, in partial cross section, of the cam-like member of the embodiment of Fig. 11;
Fig. 14 is a partly cross-sectional view of a fourth embodiment of the device, suitable for "nonsymmetrical" sprinklers, with a double-ramp cam-like member pointing downwards and rotating together with the sprinkler;
Fig. 15 is a side view, in cross section, of the cam-like member of Fig. 14 and its immediate surroundings;
Fig. 16 shows a partly cross-sectional view of a fifth embodiment of the device, including an adjustable angular-sweep sprinkler;
Fig. 17 is a top view of the cam-like member of the embodiment of Fig. 16, including a schematic outline of the housing of this embodiment, and
Fig. 18 shows the inlet portion of the embodiment of Fig. 16 with the inner member fully extended.

There is seen in Fig. 1 a housing 2 of, in this embodiment, a substantially rectangular cross section, open on top (see Fig. 2) and provided with a bottom 4 having a . number of drain holes 6 through which water collecting in the housing 2 can drain away into the soil in which the housing 2 is buried right up to its upper edge (see Fig. 7). The housing 2 is fixedly attached, e.g., by welding, to a tubular member 8, the lower end 3 of which is connectable to a water supply line. This tubular member 8 is the first, or outer, stationary member of a pair of telescoping tubular members, the second, or inner member 10 of which is upwardly extendable against the force of a restoring spring 12 by application of water pressure, and downwardly retractable from the extended position by the restoring force of the spring 12, when the water pressure is cut off or reduced below a given threshold. The lower end of the inner member 10 is provided with a shoulder 14 against which bears the restoring spring 12. While a spring is indeed the obvious source of the restoring force required, it is by no means the only one available and in cases where the added length of the outer member 8 required due to the use of the spring 12 (i.e., the fully compressed length of this spring) cannot be accommodated due to, e.g., shallow soil, other forces may be employed such as gravity or hydraulic forces.
To the upper end of the inner member 10 there is rotatably attachable a rotary sprinkler 16. This sprinkler is of the type which, in plan view, is circumscribable by a geometric figure larger in longitudinal extent than in width, such as a narrow rectangle, a narrow ellipse or the like. In the embodiment shown in the Figure, the sprinkler is a standard model of the hammer or percussion type, but other types can be used as well, for instance reaction sprinklers. In the retracted state of the inner member 10, the sprinkler assumes a non-operative position within the housing 2, and in the extended state of the inner member 10, an operative position without and above the housing 2.
To the top of the sprinkler 16 there is fixedly attached a cover plate 18 which is of a shape substantially fitting the top of the housing 2 (see Fig. 2). In the retracted position of the sprinkler 16, the cover plate 18 preferably rests on four corner supports 20, as well as on the end face of at least one rail 22, the main purpose of which will be explained hereinbelow. The relative dimensions of all the elements cooperating in the extending and restricting ("disappearing") movement of the sprinkler are such that when the cover plate 18 rests on its supports 20, the restoring spring 12 is still somewhat compressed and, therefore still exerts a pulling force on the sprinkler 16 (via the inner member 10) and, thus, on the cover plate 18, which thereby tightly covers the housing 2.
The housing 2 is further provided with a sliding shield 24, which is fixedly attached to, and moves together with, the inner member 10, and is of such a shape and size as to substantiably fill the free cross section of the housing. In the fully extended state of the inner member 10, the shield 24 has moved up high enough inside the housing 2 to constitute a temporary cover plate (the permanent cover plate 18 now being high above the housing 2, on top of the extended sprinkler 16 - see Fig. 8), preventing dirt from entering the housing 2. In the course of its movement from its lowermost position close to the bottom 4 of the housing 2, to its topmost position, the sliding shield 24 will also clear the interior of the housing 2 of any dirt, gravel or soil lumps that might have deposited in it. The four corners of the shield 24 are suitably recessed, to allow for the corner supports 20 which, as is seen in Fig. 1 extend from near the top of the housing 2 down to the bottom 4. These supports need not be of a square cross section as shown in Fig. 2. They can be quadrant - shaped or be in the form of a fillet. A suitably shaped groove allows also for the passage of the rail 22.
As so far described, it is clear how, upon application of water pressure to the outer member 8 connected to the water supply line, the inner member 10, acting like a piston, will extend, raise the sprinkler 16 which, once it is outside of the confines of the housing 2, will start rotating and irrigating. It is also obvious that when the water pressure is cut off, the restoring spring 12 will pull the inner member 10 downward and together with it, the shield 24 and the sprinkler 16. However, as the upper part of the sprinkler 16, the "whip" 17 will be able to enter the housing 2 only if in longitudinal alignment with same, and as the whip's angular position with respect to the housing 2 at the moment water pressure is cut off, is liable, and even likely, to be in a position of misalignment, means are provided in the form of a cam-like member 26, fixedly attached to, and rotating together with, the sprinkler 16, which member 26 cooperates with guide means in the form of a guide rail 22 (Fig. 2) attached to, or integral with, the housing 2, to such effect that, when the water pressure is cut off, causing the upwardly extended inner member 10 carrying the sprinkler 16 to be retracted by the restoring spring 12, the rotary sprinkler 16, prior to its complete re-entry into the housing 2 and regardless of its angular position at the instant the water pressure was cut off, is automatically oriented to assume a position of alignment with the elongated cross section of the housing 2, so that, upon further retraction, the sprinkler 16 will freely enter the housing 2.
This orientation is effected by appropriately designed slopes or ramps provided on the active face of the cam-like member 26, which ramps, making contact, upon retraction, with the preferably rounded end of the guide rail and acting as an inclined plane, causes the cam-like member 26 to rotate until the deepest point of the sloping ramp ( as seen from the guide rail 22) makes contact with the guide rail 22.
At this moment, the sprinkler 16, which rotates together with the cam-like member 26 is in proper alignment with the housing 2. At this deepest point of the sloping ramp, there is, however, provided a register means in the form of a slot 28 (Figs. 4.5,6) of a sufficient width and depth to let the cam-like member 26 (together with the sprinkler 16) slide along the guide rail 22. It is this slot 28 which, in conjunction with the guide rail 22, makes the cover plate 18 "register" with the top of the housing prior to the onset of the above-mentioned further (and final) retraction.
Fig. 4 shows an embodiment of such a cam-like member 26. This embodiment is a double-ramp face cam, the ramps 30 and 32 being constituted by parts of lefthand and righthand spatial curves, respectively.
Another embodiment is seen in Fig. 5, in which the cam-like member 26 is a quadruple-ramp face cam, the ramps 34, 36, 38 and 40 being constituted by parts of pairs of lefthand and righthand spatial curves, respectively. Fig. 6 shows yet another embodiment in which the cam-like member is a single-ramp face cam, the ramp 42 being constituted by a single turn of a spatial curve.
In a further embodiment (not shown), the cam-like member is a double-ramp face cam, the ramps being constituted by half turns each, of two equal-handed spatial curves.
While it is advantageous to use for the above-mentioned spatial curves helices or parts thereof, other spatial curves may be used as well, as long as the inclined-plane effect is obtained, i.e., the curve is at no point self- jamming.
The cam-like members shown in Figs. 4 and 6 will always return the sprinkler 16 in the same position relative to the housing 2. This is important for sprinklers in which the "whip" 17-is not symmetrical, i.e., the distance from the extreme "hammer" end 19 to the axis of rotation is not identical to the distance from the extreme "wedge" end 21 to the axis of rotation. In such cases use of a cam-like member such as shown in Fig. 5 would necessitate the provision of a housing longer than the actual "whip", so that the longer.arm can be accommodated on either side.
For symmetrical "whips", cam-like members 26 can be used in which the ramp or ramps extend over an angular range of approximately 180° only, in which case two guide rails 22, on two opposite housing walls are required.
For certain types of sprinklers, the guide rail 22 can be replaced by one or two guide pins 44 (Fig. 3) attached to, or integral with, the housing 2.
Figs. 7 and 8 show the sprinkler device according to the embodiment of Fig. 1 as mounted in the field, with Fig. 7 showing the device in the retracted, non-operative position inside the housing 2, with the cover plate 18 substantially flush with the ground, and Fig. 8 showing the device in the extended, operative state, in which the sprinkler is above ground and irrigates while rotating.
As can be seen from Fig. 8, the shield 24 in its topmost, operative position also contributes to the stability and rigidity of the extended device, preventing undesirable wobbling.
Figs. 9 and 10 show another embodiment of the sprinkler device in which the cam-like member 51 is fixedly attached to the inner member 10 of the telescoping pair by means of a threaded ring 50, which presses it, via the shield 24, against a shoulder of the inner member 10. The cam-like member 51 is stiown to better advantage in Fig. 10 and is seen- to be a quadruple-ramp face cam, similar to that shown in Fig. 5. The ramps 52 lead into slots 54 on both sides of the cylindrical body, into either of which slots drops the guide roller 56 rotatably mounted on a pivot 58 fixedly attached to the lower portion Of tne percussion springer 16. For smoother cam action it wouldbe advantageous to have two oppositely located guide rollers 56. Proper angular orientation of the cam-like member 51 with respect to the longitudinal axis of the housing cross section as defined by the shield 24 is best ensured by pinning the cam-like member 51 to the bottom of the shield 24, to which end the flange 60 of the member 51 is provided with a hole 62 (Fig. 10).
The sprinkler 16 is attached to the inner member 10 with the aid of a sleeve 64, the upper, threaded end of which tightly fits the internal thread of the sprinkler-inlet. The outside diameter of the main portion of the sleeve 64 is a running fit in the stepped-down end of the inner member 10 and, once screwed home in the sprinkler 16, moves together with the latter. The lower end of the sleeve 64 has two steps, a first step on which is placed a sealing washer 66 for a purpose to be explained below, and a second step against which bears a compression spring 68 which is slightly stronger.
When water is now introduced through the connecting socket 3, the inner member 10 is extended, raising the sprinkler 16 above ground level. However, as long as the roller 56 is inside the slot 54, the sprinkler 16 cannot rotate. Only when pressure is high enough to push out the sleeve 64 relative to the inner member 10, will the roller 56 leave the zone of the ramps 52 and permit the sprinkler 16 to rotate. At this stage the sealing washer 66 will have hit the end of the bore of the inner member 10, serving both as a stop for the sleeve 64 and as a seal, preventing water from leaking through the necessary clearance of the above-mentioned running fit between the sleeve 64 and the reduced end of the inner member 10. Uhen the water is turned off, pressure gradually drops and the first to be retracted, due to its strong spring 68, is the sleeve 64, causing the sprinkler 16 to assume the proper orientation relative to the housing 2; only then does the inner member 10 complete its retraction and fully returns the sprinkler 16 into the housing 2.
Another embodiment of the sprinkler device according to the invention is shown in Fig.s 11, 12 and 13. This embodiment differs from the previously presented examples first of all in the shape of the housing 69, the bulk of which has been reduced to a minimum, as is particularly obvious from the top view of Fig. 12 (in which the cover 18 has been omitted). Mechanically, this embodiment is different in that the cam-like member 70 does neither rotate (as in Fig. 1) nor move up and down (as in Figs. 1 and 9), but is rigidly attached to a flange 71 of the outer, stationary member 8 which, in this embodiment, is integral with the housing 69. The cam-like member 70 of this embodiment is best understood from Fig. 13 and is seen to be a quadruple-ramp face cam similar to that shown in Fig. 10. The ramps 72 lead into long slots 74 on both sides of the cylindrical body, into either of which slots drops the guide roller 56 rotatably mounted on a pivot 58 fixedly attached to the lower portion of the sprinkler 16. The cam-like member 70 is provided with a flange 76 having a number of holes 78 matching threaded holes in the flange 71, to which it is connected by means of screws 80.
In an embodiment to be used for what was earlier defined as "non-symmetrical" whips 17, the housings for which, to reduce size to a minimum, are nonsymmetrical, too, double -or single-ramp cams can be used, which will always return the sprinkler 16 in the same position relative to the housing 69.
Such an arrangement is shown in Fig. 14 which in other respects resembles that of the embodiment of Fig. 9, except that the cam-like member 81 points downwards, rotates together with the sprinkler 16 and is fixedly attached to the lower portion of the sleeve 65.
Fig. 15 is a cross-sectional side view of the cam 81 and its immediate surroundings. It is seen that the guide pin 82 is attached to the inner member 10. Instead of a guide pin, a guide rail could be used.
The device according to the invention is also usable with what are known as "adjustable angular sweep" percussion sprinklers to be used at the edges of lawns or gardens where sprinkler sweep should not exceed 180°, and at the corners, where sweep should not exceed 90°. These sprinklers, as such known, can be adjusted to sweep angular sectors between 30° and 300°, using settable stop means which trigger a bistable toggle mechanism that switches the sprinkler from a relatively slow "watering run" covering the preset' angle, to a relatively rapid "return run", to start a new "watering run".
Figs. 16, 17 and 18 show an embodiment conceived for use with adjustable-sweep percussion sprinklers. Of the sprinkler 16 proper, there is seen the rod-like trigger 84 which, when pushed by either one of the adjustable stops 86, 88 beyond the center point, flips the toggle arms 90, initiating sweep reversal.
In this embodiment, too, the heart of the device is the cam 85 which is seen in elevation in Fig. 16, and in plan view. in Fig. 17. It is of the double-ramp type shown in Fig. 4 and has only one position of rest, i.e., it will always return the "nonsymmetrical" sprinkler 16 shown in Fig. 16 to the same position in the housing 91, the outline of which is schematically indicated in Fig. 17. To ensure the proper orientation of the cam 85 with respect to the sprinkler, an eccentric hole 92 is provided in the slightly recessed "ceiling" 93 of the cam 85 for pinning it to the rim of the sprinkler inlet socket. The cam 85 is cooperating with a guide rail 22 which, as in Fig. 1, is attached to, or integral with, the housing 91 (Fig. 17). The effect of the ramp of the retracted cam 85 hitting the upper edge of the rail 22 is the same as was the case in the embodiment of Fig. 1: The inclined-plane effect causes the cam 85 -and, thus, the sprinkler- to rotate until the rail 22 can enter the slot 95, at which instant the sprinkler 16 is in proper alignment with the housing 91 into which it can now freely enter.
There is also seen an arcuate slot 94 in the cam "ceiling" 93, which serves to limit the possible stroke of the trigger 84 on both sides of the flip-over point. As is clear from Fig. 16, the rod-like trigger 84 passes through this slot 94.
Another advantageous feature of this embodiment is an arrangement whereby even with mains pressure turned on, no water can reach the sprinkler proper unless the inner member 10 is in the fully extended position. Yet another feature is the possibility, particularly important with reclaimed water used for irrigation purposes only. of introducing filter elements as integral parts of the device. To this end, the device is provided with a jacket 96 completely surrounding what was in previous embodiments the outer member 8. The jacket 96 which, in the present embodiment, is integral with the housing 91, and to which the entire mechanism, including the outer member 8, is attached by means of screws 98, is provided with two alternative inlet sockets 100 and 102, with the nonused socket being plugged up. (The lower socket 102 cannot be used with filter elements.) The annular space between the jacket 96 and the outer member 8 is filled with filter elements 104. As opposed to all previous embodiments, the inner member 10 is closed at the bottom and fits the outer member 8 in a piston-like fashion as is clearly seen in Fig. 16. (To avoid close tolerances, an 0-ring could be provided). The "piston" portion 106 of the bottom end of the inner member 10 is, however, short in its axial extent and is followed by a portion of a smaller diameter provided with a plurality of radial holes 108 which connect the inside of the inner member 10 with the narrow annular space 110. At a point close to the inlet socket 100, the outer member 8 is provided on its inside surface with a plurality of peripherally arranged concave grooves 112. When now water pressure has pushed up the inner member 10 as far as it will go, that is, until the upper shoulder 114 of the reduced-diameter portion contacts the lower rim 116 of the guide sleeve 117(a situation illustrated in Fig. 18), it is clearly seen that the water can now enter the concave grooves 112, flow past the "piston" portion 106 and enter the inside of the inner member 1C via the holes 108. From here, the water is of course free to enter the sprinkler 16.
In this embodiment, the shield 118 is round and fixedly attached to the upper portion of the inner member 10. It is provided with a radial slot (not shown), similar to slot 95 of the cam 85, engaging the rail 22, which prevents the inner member 10 from rotating about its axis. While absence of such rotation is essential for use of this embodiment with the above-mentioned "adjustable angular sweep" percussion sprinkler, such a feature is also important when other sprinkler types are used, as a rotary movement of the inner member 10 would greatly interfere with the uniformity of the sprinkling effect. Such movement has indeed been precluded in all embodiments of the invention. (A simple pin-and-slot arrangement to take care of this problem in the embodiment of Fig. 11 has been omitted in the drawing for the sake of clarity).
As can be seen in Fig. 16, the housing portion immediately above the jacket 96 is slightly tapering towards the upper portion which accommodates the sprinkler proper, in order to provide an annular space for the drain holes 6 on the one hand and, on the other, not to increase the diameter of the upper end of this tapering portion, which would also entail an increase in the width of the cover 18. As it is, the surface area of the cover 18 as indicated in Fig. 17 (or Fig. 12) is about 1/5 of the surface area of a round cover which would be required for a cylindrical housing accommodating the same ; type of sprinkler. While the functional advantages of the narrow, noncircular cover were pointed out earlier, the : design according to the invention also affords a substantial saving in material for both the noncircular cover and the noncylindrical housing.
Although in the embodiments so far mentioned the cams were all of the face type, they could also be barrel-type cams, with the grooves in the barrel cam constituting the equivalent of the ramps in the face cams.
While particular embodiments of this invention have been described, it will be evident to those skilled in the art that the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodiments and examples are therefore to be ton- sidered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. A disappearing sprinkler device connectable to a water supply line of the kind comprising a housing (2), which housing is open at least at its top; a pair of telescoping, tubular members (8,10), a first member (8) which is stationary, and a second member (10) which is upwardly extendable by application of water pressure and downwardly retractable upon said water pressure being reduced to below a given threshold; a rotary sprinkler (16) of the type which, in plan view, is circumscribable by a geometric figure larger in longitudinal extent than in width, which sprinkler is rotatably attachable to said second tubular member and assumes, in the retracted state of said second member, a non-operative second member, a non-operative position within said housing and, in the extended state of said second member, an operative position without said housing, a cover plate (18) for said housing, which cover plate is fixedly attached to said sprinkler and has a shape substantially fitting the top of said housing. and, in said retracted state, covering said top, characterised in that the housing (2) is of an elongated cross-section and in that the device further comprises a cam-like member (26; 51; 70; 81; 85) co-acting with guide members (22; 44; 56; 82) to such effect that the reduction of said water pressure to below a given threshold causes said upwardly extended second member (10) carrying said sprinkler (16) to be retracted, said rotary sprinkler, prior to its complete re-entry into said housing and regardless of its angular position at the instant said water pressure was thus reduced, being automatically oriented to assume an angular position of alignment with the elongated cross-section of said housing (2) so that, upon further retraction, it will freely enter said housing, said cam-like member being provided with register means (28; 54; 74; 95) which, in conjunction with said guide means, accurately and positively define the angular position of said cover plate (18) relative to said housing top during said further retraction.

2. A sprinkler device as claimed in claim 1, characterised in that spring means (12) are provided to retract said second member (10) upon said water pressure being cut off.

3. A sprinkler device as claimed in claim 1 or claim 2, characterised in that a sliding shield (24) is provided in said housing (2), which shield is fixedly attached to, and moves together with, said second member (10), and substantially fills the free cross-section of said housing._'

4. A sprinkler device as claimed in any one of claims 1 to 3, characterised in that said cam-like member is a double-ramp face cam, said ramps being constituted by parts of lefthand and righthand spatial curves (30, 32; Fig.4) respectively.

5. A prinkler device as claimed in any one of claims 1 to 3 characterised in that said cam-like member is a quadruple-ramp face cam, said ramps being constituted by parts of pairs of lefthand and righthand spatial curves (34,36,38,40; Fig.5), respectively.

6. A sprinkler device as claimed in any one of claims 1 to 5, characterised in that said cam-like member is a single-ramp face cam, said ramp being constituted by a single turn of a spatial curve (42;Fig.6).

7. A sprinkler device as claimed in any one of claims 1 to 6, characterised in that said cam-like member (26) is attached.to, or integral with, a body of said rotary sprinkler.

8. A sprinkler device as claimed in any one of claims 1 to 6, characterised in that said cam-like member (26) is fixedly attached to, or integral with, said first member (8) .

9. A sprinkler device as claimed in any one of claims 1 to 6, characterised in that said cam-like member (26) is attached to, or integral with, said second member (10).

10. A sprinkler device as claimed in any one of claims 1 to 9, characterised in that two guide means (22) are provided to co-operate with said cam-like members.

11. A sprinkler device as claimed in any one of claims 1 to 10, characterised in that said guide means is a rail (22) attached to, or integral with, said housing.

12. A sprinkler device as claimed in any one of claims 1 to 10, characterised in that said guide means is in the form of at least one pin (44) attached to, or integral with, said housing (2).

13. Asprinkler device as claimed in any one of claims 1 to 10, characterised in that said guide means is a roller (56) attached to said sprinkler.

14. Asprinkler device as claimed in any one of claims 1 to 10, characterised in that said guide means is a pin (82) attached to said second member (10) and projecting into the inside thereof.

15. A sprinkler device as claimed in any one of claims 1 to 14, characterised in that said register means is at least one slot (28; 54; 74) into which said guide means enters upon said further retraction.

16. A sprinkler device as claimed in any one of claims 1 to 15, characterised in that there is further provided a jacket (96) surrounding said first member (8) with clearance.

17. A springer device as claimed in claim 16, characterised in that there is provided filter means (104) mountable in said clearance.

18. A sprinkler device as claimed in any one of claims 1 to 17, characterised in that the lower end of said member (10) is closed (106) and, over a relatively short axial length, fits the inside of said first member (8) in a piston-like fashion.

19. A sprinkler device as claimed in claim 18, characterised in that closely above said piston-like portion (106), said second member (10) is provided with a plurality of peripherally arranged holes (108) leading into the inside of said second member (10).

20. A sprinkler device as claimed in claim 16, characterised in that said first member (8) is provided on its inside surfaces with a plurality of peripherally arranged grooves (112).