US3331292A - Extensible actuator with improved sealing means - Google Patents

Description

July 18, 1967 w. SEABLOM EXTENSIBLE ACTUATOR WITH IMPROVED SEALING MEANS Filed June 6, 1966' INVENTOR. Wendell (NM!) Saab/om BY Attorneys L\ g 4 4 5. F e i! 3 a Q. m w a a r\ 6 M 4 6 5 x 2 I "a w W 4I(\ .lh\ J w 4 m United States Patent 3,331,292 EXTENSIBLE ACTUATOR WITH IMPROVED SEALING MEANS Wendell Seablom, Santa Rosa, Calilrl, assignor to Controlled Mercury Switch Corporation, Santa Rosa, Calif.,

a corporation of California Filed June 6, 1966, Ser. No. 555,633 4 Claims. (Cl. 92-108) The present invention is a continuation-in-part of my copending application Ser. No. 407,255, filed Oct. 28, 1964, now US. Patent 3,263,929, which was a continuation-in-part of application Ser. No. 376,989, filed June 22, 1964, and now abandoned, which was a continuationin-part of application Ser. No. 316,716, filed Oct. 16, 1963 and now abandoned.

This invention relates to sprinkler heads and systems of a type employing extensible heads as are particularly useful in overhead distribution of water to lawns and other crops.

In spraying water onto lawns from sprinkler heads disposed at various locations about the terrain, it is often desirable in fixed installations to have the sprinkler head mounted flush with or below the ground. This is particularly desirable, for example, when grass is to be mowed or other crops harvested. On the other hand, it is not unusual to desire the sprinkler head to discharge a stream of liquid from a position well above the ground level. For example, to minimize the pipe layout, it may be desired to locate sprinkler heads in the midst of shrubbery or other obstructions. In such a case, it can be useful to have a sprinkler head originate a stream of liquid from a raised position to discharge over the top of the shrubbery or the like. However, if the head is fixed in place it can become an annoyance when working in and about the shrubbery.

Consequently, it is a general object of the present invention to provide an improved extensible sprinkler head.

In extensible sprinkler devices, it is usually desirable that leakage be minimized to conserve water and maintain the premises.

Another object of the invention is the provision of an extensible sprinkler head provided with improved means for insuring against leakage both within the device and out of the device.

Other objects of the invention will be pointed out in the following detailed description of a preferred embodiment of the invention when considered in conjunction with the accompanying drawings.

In the drawings:

FIGURES 1 and 2 are elevation section views showing a sprinkler head, according to the invention, in its projected and retracted positions respectively.

In general, a sprinkler head has been provided herein of a type wherein a member is formed to provide an elongated cylinder and another member provides a piston movable between advanced and retracted positions within the cylinder. The piston is formed with a portion disposed to be extensible with respect to one end of the cylinder. The piston and the extensible portion are formed with a flow passage to pass liquid'from one side thereof to be discharged on the other form from the end of the extensible portion outside the cylinder.

A valve member is carried by the cylinder and telescopically coacts with the piston in order to block the flow passage when the piston is in its retracted position and to open the flow passage when the piston is in its advanced position. The cylinder is arranged to include means serving to pass liquid under pressure into the cylinder to one side of the piston in order to move the piston to its advanced position and thereby open the flow 3,331,292 Patented July 18, 1967 passage. The applied liquid then passes through the flow passage and discharges out the extensible portion.

Means for providing improved sealing against leakage internally and externally of the sprinkler device have been provided using resilient O-rings but arranged to cooperate with laterally enlarged or constricted zones formed to slidably engage and laterally press increasingly against the O-rings as the piston arrives at its advanced or retracted positions.

Referring to FIGURES 1 and 2 there is shown an embodiment particularly suitable for manufacture by injection molding techniques and incorporating features and advantages as now to be described. A body shell construction generally designated 5 having means for passing fluid into and out of a cylinder 6 is assembled from a number of injection molded parts. Thus a cylindrical body member 7 is formed to provide cylinder 6. A fluid passage 8 is provided at the bottom of body member 7 for passing fluid into and out of cylinder 6. Water under pressure for spray distribution will normally enter passage 8 from a water pipe such as indicated at 9. Another fluid passage 11 is formed at the upper end of cylinder 6 from an assemblage of parts to be described further below whereby further transverse forming operations are not required.

Passage 11 discharges fluid ahead of a piston assembly 10 as it moves upwardly within cylinder 6. Fluid discharging via passage 11 is directed downwardly along the outside of body member 7 via downspout 13 which stands free of the side wall of body member 7.

A hollow cylindrical post 14 is formed in a counter bored fashion coaxially within cylinder 6. The lower end of post 14 is sealed closed by a plug 15 bonded to cover the open lower end. Plug 15 includes a stem 15a which serves as a handle when inserting plug 15.

The lower end of bodymember 7 is formed with anchoring means serving to stabilize the sprinkler when buried. The anchoring means comprises a skirt 17 of generally cylindrical construction bonded or otherwise fixed to the body member 7 to depend therefrom as an extension. A plurality of fixed vanes 18 are provided, lying transversely of skirt 17 and bonded both to the bottom of body member 7 and to skirt 17 so as to brace the skirt as well as to resist rotation of body member 7 when lodged in the ground. Skirt 17 is formed to include a relieved portion 19 which serves to accommodate a transversely extending pipe adapted to be coupled, as by a suitable T or elbow connection to downspout 13.

A piston assembly includes a piston head portion 12 formed of an annular member 23 bonded to a generally flanged end portion 24 formed on the lower end of an elongated hollow piston extension 26. Flanged portion 24 includes an annular rib 27 inserted and bonded into a circular groove formed in the upper surface of member 23. In this manner a pair of O-rings 28 can be captured around the inner and outer circumference of the piston head 12. Members 23 and 24 then are bonded together in a conventional manner by bonding cement.

At the upper end of the cylinder 6 fluid passage 11 serves to pass fluid into and out of cylinder 6. The upper end of cylinder 6 is otherwise closed by a transversely extending molded end member 29 formed at the upper end of downspout 13. The lower end of downspout 13 is braced by being passed through a rigid guide 31.

A cap 33 cooperates with a groove formed in the upper edge of member 29 so as to capture an O-ring 34 therebetween. O-ring 34 serves to form a seal around piston extension 26 during its movement between retracted and advanced positions.

At the upper end of piston extension 26 a spray element or other fluid discharge means 36 threadedly engages a counter bored portion 37 of 26. Therefore, various types of spray elements can be employed with the same basic elevator device.

Alignment means serve to maintain radial positioning of spray element 36 with respect to body member 7. Thus, a tongue 38 is fixed with respect to extension 26 and locked in place by spray element 36. The lower end of tongue 38 is slidably engaged through a slot 47 formed through the upper end of the post 14. The length of tongue 38 is such that piston head 12 abuts the upper end of cylinder 6 before the lower end of tongue 38 passes out of slot 47.

As thus arranged it will be clear that tongue 38 serves to maintain radial alignment of extension 26 during movement between retracted and projected positions without interfering with the operation thereof. Extension 26 therefore will not be rotated to cause the orientation of spray element 36 to be misdirected with respect to its assigned region of coverage.

Slot 47 formed in the upper end of post 14 serves to guide tongue 38 by slidable engagement therebetween.

If it were not for the constricting nature of slot 47 in post 14, tongue 38 would be permitted to be rotated with respect to post 14 due to the enlarged hollow interior dimension of post 14. Thus it will be apparent that slot 47 forms a constriction in the hollow interior of post 14 which precludes rotation thereof during projection and retraction of the piston assembly.

Tongue 38 is formed, however, with a relieved portion disposed to register adjacent slot 47 when piston extension 26 is in its retracted position. The relieved region more particularly is shown as the necked down relieved portion 40 which is formed to include a transversely extending ledge 41 on opposite sides of tongue 38. The relieved portion 40 is dimensioned so as to clear the constriction formed by slot 47 and permit rotation between tongue 38 and post 14 so as to dispose the ledges 41 beneath the overhanging lip 42 of slot 47.

Frequently, it is desired to change spray elements 36. For this purpose a hexagonal nut 49 or the like is formed at the upper end of element 36. When a wrench is applied to nut 49 a considerable torque can be developed upon the piston extension 26 which, if not dissipated through the body of the apparatus, can serve to rupture or otherwise damage the device, such as by twisting tongue 38.

Means are provided whereby torque applied to extension 26 is transmitted to body construction via L-shaped vanes 51.

Thus when extension 26 is in its retracted position the necked down region 40 serves to permit the piston assembly to be rotated within cylinder 6. Beneath the piston head, annular member 23 is formed with three downwardly extending abutments 43. Each abutment 43, when extension 26 is in its retracted position, extends downwardly sufliciently to engage the upper end of L-shaped upright vanes 51 whereby rotation of the abutments 43 with respect to vanes 51 will ultimately be limited by engagement therebetween. Accordingly, the abutment means serves to transfer torque applied to extension 26 into the body construction of the head assembly.

The upper end of post 14 includes a plurality of grooves 44 extending along the outer surface of post 14 which functions as a valve member. Grooves 44 are disposed to be encircled by a sealing ring, such as the resilient O-ring 28 at a position inter-mediate the ends of grooves 44 when the piston is in its advanced position. In this manner fluid can pass from cylinder 6 int-o the hollow interior of extension 26 to be discharged via spray element 36. Thus, sealing rings 28 is always maintained in place by the exterior surface of post 14. It will be further noted that the upward travel of the piston is limited by molded end cap member 29 so as to define the advanced position of piston assembly at a point which is reached prior to carrying sealing ring 28 upwardly beyond the end of post 14.

To insure against leakage internally, and externally, O- rings 28 and 34 are positively compressed increasingly as piston assembly 1t arrives at its projected and retracted positions.

Thus, a zone 30 extending continuously around the interior wall surface of body member 7 bulges inwardly slightly and gradually to provide a tapered reduction in the diameter of cylinder 6 on the order of .008 inch for a body member 7 otherwise having an inside diameter on the order of 1 /3 inches. When piston assembly 10 is moved to its retracted position, zone 30 compresses the outer O-ring 28 radially inwardly to positively insure against leakage past piston head 12 at zone 39. A similar radially inward constriction zone 32 is formed around the upper end of cylinder 6 so as to cooperate with the outer one of O-rings 28 as piston head 12 arrives at its advanced position.

At the level of zone 30 post 14 has been enlarged to form a sealing zone 35 extending continuously around post 14. The tapered enlargement of zone 35 runs to a maximum increase in post diameter on the order of .008 inch. Zone 35 cooperates with the radially inner one of O-rings 28 whereby as piston head 12 arrives at its retracted position, radially outward compression is positively applied to the O-ring to insure proper sealing.

Further, piston extension 26 includes lower and upper sealing enlargements forming zones 45, 46 respectively, each of which slightly enlarges the diameter of extension 26 and extends continuously around extension 26. Zones 45, 46 are disposed axially of extension 26 to cooperate with the O-ring 34 carried around the opening through which extension 26 moves, so that as piston assembly 10 arrives at either its retracted or advanced positions, positive sealing developes by increasingly compressing O-ring 34 thereat.

A pressure system of a type, for example, as shown in the above identified US. Patent 3,263,929 controls the movement of piston assembly 10. Thus pressure applied to assembly 10 to raise it to an advanced position enters fluid passage 8 to apply pressure to the underside of the piston head portion 12. Fluid ahead of piston head portion 12 exhausts via downspout 13. In order to retract piston extension 26 the fluid pressure system is reversed so as to apply pressure to the fluid passages defined by downspout 13 and to exhaust fluid via passage 8. Suitable means for reversing the fluid pressure connections to the system are shown in the above identified patent, for example, at FIGURE 1 thereof.

What is claimed is:

1. In a fluid operated actuator of a type for moving an element between advanced and retracted positions, a cylinder, a piston movable along said cylinder between advanced and retracted positions, fluid passage means at opposite ends of said cylinder for supplying fluid under pressure to one side of said piston and for exhausting fluid from the other side to move said piston between said positions, a member extending axially within the cylinder and telescopically received through said piston, a resilient -O-ring carried by said piston to form a seal between said member and the piston during movement of the piston therealong, said member including a slightly enlarged portion extending continuously therearound and axially disposed to increasingly compress said O-ring as said piston arrives at its retracted position.

2. In a fluid operated actuator of a type for moving an element between advanced and retracted positions, a first member forming cylinder, a second member forming piston movable along said cylinder between advanced and retracted positions, fluid passage means at opposite ends of said cylinder for supplying fluid under pressure to one side of said piston and for exhausting fluid from the other side to move said piston between said positions, a third member extending axially within the cylinder and telescopically received through said piston, a first resilient O-ring carried by said piston to form a seal between said third member and the piston during movement of the piston therealong, said third member including a slightly enlarged portion extending continuously therearound and axially disposed to increasingly compress said O-ring as said piston arrives at its retracted position, a second resilient O-ring carried by one of said first and second members for sliding engagement with a surface of the other of said first and second members, said surface tapering slightly radially of said other member in a zone thereof extending continuously around said other member, said zone being axially disposed to cooperate with said second O-ring at one of said advanced and retracted positions of said second member to increasingly compress said second O-ring thereat.

3. In apparatus of a type having a hollow body shell, 1

a piston movable between retracted and advanced positions within said body shell wherein the piston includes a hollow extension protruding via an opening out of an end of the body shell and carries a spout element supported by said extension for discharging fluid therefrom,

and further having first fluid passage means for passing fluid under pressure into said body shell at one end thereof to move said piston toward the other end of said body shell, and second fluid passage means at said other end for passing fluid lying ahead of said piston out of said shell, the improvement comprising a resilient O-ring encircling said piston and slidably engaging the interior wall of said body shell, said body shell being slightly constricted peripherally therearound to cooperate with said O-ring at one of said advanced and retracted positions of said piston to increasingly compress said O-ring thereat, another resilient O-ring, the last named O-ring being disposed around said opening and disposed between said extension and said body shell, said extension being slightly radially enlarged to cooperate with the last named O-ring at one of said advanced and retracted positions of said piston to increasingly compress the last named O- ring thereat,

4. In a fluid operated actuator of a type for moving an element between advanced and retracted positions, a cylinder, a piston movable along said cylinder between advanced and retracted positions, fluid passage means at opposite ends of said cylinder for supplying fluid under pressure to one side of said piston and for exhausting fluid from the other side to move said piston between said positions, a resilient O-ring encircling said piston and slidably engaging the interior wall surface of said cylinder, said wall surface tapering slightly radially inwardly in a zone thereof extending continuously around said cylinder, said zone being axially disposed to cooperate with said O-ring at one of said advanced and retracted positions of said piston to increasingly compress said O- 5 ring thereat, an extension carried by said piston to protrude through an opening in one end of said cylinder, a resilient O-ring carried around said opening and disposed for sliding engagement with the periphery of said extension, the periphery of said extension being slightly enlarged at a zone thereof extending continuously around said extension, the last said zone being disposed axially of said extension to cooperate with the O-ring around said opening at one of said advanced and retracted positions to increasingly compress same thereat.

References Cited UNITED STATES PATENTS 1,484,888 2/1924 Johnson 239-204 1,495,949 5/1924 Carroll 92110 2,595,598 5/1952 Morton 239-204 3,063,425 11/1962 Be Vier et al 92-108 X 3,203,246 8/1965 Horwitt et 'al. 251 X MARTIN P. SCHWADRON, Primary Examiner. I. C. COHEN, Assistant Examiner,

Claims (1)

1. 2. IN A FLUID OPERATED ACTUATOR OF A TYPE FOR MOVING AN ELEMENT BETWEEN ADVANCED AND RETRACTED POSITIONS, A FIRST MEMBER FORMING CYLINDER, A SECOND MEMBER FORMING PISTON MOVABLE ALONG SAID CYLINDER BETWEEN ADVANCED AND RETRACTED POSITIONS, FLUID PASSAGE MEANS AT OPPOSITE ENDS OF SAID CYLINDER FOR SUPPLYING FLUID UNDER PRESSURE TO ONE SIDE OF SAID PISTON AND FOR EXHAUSTING FLUID FROM THE OTHER SIDE TO MOVE SAID PISTON BETWEEN SAID POSITIONS, A THIRD MEMBER EXTENDING AXIALLY WITHIN THE CYLINDER AND TELESCOPICALLY RECEIVED THROUGH SAID PISTON, A FIRST RESILIENT O-RING CARRIED BY SAID PISTON TO FORM A SEAL BETWEEN SAID THIRD MEMBER AND THE PISTON DURING MOVEMENT OF THE PISTON THEREALONG, SAID THIRD MEMBER INCLUDING A SLIGHTLY ENLARGED PORTION EXTENDING CONTINUOUSLY THEREAROUND AND AXIALLY DISPOSED TO INCREASINGLY COMPRESS SAID O-RING AS SAID PISTON ARRIVES AT ITS RETRACTED POSITION, A SECOND RESILIENT O-RING CARRIED BY ONE OF SAID FIRST AND SECOND MEMBERS FOR SLIDING ENGAGEMENT WITH A SURFACE OF THE OTHER OF SAID FIRST AND SECOND MEMBERS, SAID SURFACE TAPERING SLIGHTLY RADIALLY OF SAID OTHER MEMBER IN A ZONE THEREOF EXTENDING CONTINUOUSLY AROUND SAID OTHER MEMBER, SAID ZONE BEING AXIALLY DISPOSED TO COOPERATE WITH SAID SECOND O-RING AT ONE OF SAID ADVANCED AND RETRACTED POSITIONS OF SAID SECOND MEMBER TO INCREASINGLY COMPRESS SAID SECOND O-RING THEREAT.

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