IL33246A - Swing arm for a rotary water sprinkler - Google Patents

Description

rpaiaO moaa¾» npjnana ynt SWING ARM FOR A ROTARY WATER SPRINKLER The Invention relates to e owing arm fop effecting rotary spvement of a rotary water ap inkier* A known type of rotary water sprinkler includes a awing arm having a spoon-ohaped head and an integral boss coaxial with he axle of rotation of the sprinkler arranged to he itted on a pivot mounted on a tody portion of the aprinkier* Xn uae, a water jet iasuee from a nozzle mounted on the body portion to impinge lii the head and thereby dive the awing arm around the axle of the pivot end to effeot either continuous rotary movement Or rotary oaoillation throug a pre* determined eeotor of the body portion of the sprinkler* dependent upon the type of sprinkler.

When the hearing surfaces of the awin arm boss have beoome worn it haa been necessary either to rehore the hoaa and insert an appropriate bush or to fit a new awing arm* The invention is Intended to mitigate theae disadvantages.

According to the invention* a rotary water aprinkler Of the kind comprises an inlet pipe, a body portion rotatably mounted on aald inlet pipe, a nozzle mounted on aald body portio and oommunieatlng therethrough with aal nlet pipe, a awing arm rotatable relatively to the body portion into and out of impacting engagemen therewith and having a spoon-shaped head which* during operation of the aprinkler* la impinged by a jet of water from said nozzle to effeot aald impaoting engagement and a helioal torsion spring acting between the awing arm and the body portion in oppoaltlon to the turning of the awing arm by aald jet of water, the sprinkler including a pivot pin on said "body portion, a boss removably mounted on eaid pivot pin and having a ange against which one end of said torsion spring engages, a oollar removably secured to said pivot pin to hold said boss axlally thereon and providing an abutment for the other end of said torsion springy and interengaging surfaces on said, boss andi said swing arm supporting said swing arm from said boss and locking said swing arm to said boss for rotation therewith* Preferably the looking means comprises oireum erentiall spaced tongues on the arm or the boss and arranged to pass through corresponding axlally extending throughweye on the other of the arm or the boes» the throughways giving acoess to an undercut recess in which said tongues when looated in the throughways are insertable by relative circumferential movement between the arm and the boss to prevent the boss and arm from being separated axially.

Suitably the boss is formed from a material having different wearing characteristics than that from which the arm is formed.

The invention also includes the combination of a swing arm for a rotary water sprinkler and a removable boss as set out in any one of three immediately preceding paragraph The invention also includes a swing arm for a rotary water sprinkler having locking means interengageable with locking means on a boss as set out hereinbefore.

Two forms of a swing arm and removable boss, for a rotary water sprinkler, in accordance with the invention will now be described, by way of example, with reference to the accompanying drawings, in which: - Figure 1 is an axial section through a rotary water sprinkler showing the first swing arm partly in section and partly in elevation and the removable boss therefor in axial section; Figure 2 is a sectional view of the central portion only of the swing arm shown in Figure 1; Figure 3 is a plan view of the central portion of the swing arm shown in Figure 2; Figure k is an elevation of the removable boss also appearing in Figure 1 in axial section; Figure 5 is an elevation of the second swing arm and the removable boss therefor, the latter being shown separati from the swing arm; Fi ur 6 i t- Figure 7 is a plan view of the assembled swing arm and removable boss shown in Figure 6 .

Referring to Figures 1 to 3 > the first swing arm 10 has a spoon- shaped head 11 at one end thereof and a tail portion 12 at its opposite end. Intermediate its ends, the arm 10 is formed with an enlargement 13 substantially circular in plan, as shown in Figure 3 i and having an upwardly- acing plane surface lk positioned substantially co-axially with the axis of rotation 15 of the arm (see Figure l). A bore l6 is formed through the enlargement 13 substantially perpendicular to the plane surface lk and co-axial with the axis 15 of the arm and has its upper end formed with four circumferentially-spaced arcuate , counterbore portions 17 separated by four faces extending ohord-wise of the counterbore portions 17 at the surface lk and undercut beneath the surface lk to the full diameter of the counterbore portions to form four arcuate undercut recesses 18 of dove- tail shape in radial cross section. Axially between the lower ends of the counterbore portions 17 and undercut recesses 18 and the upper end of the bore 16 , there is a second set of circumferentially- spac ed counterbore portions 19 of smaller diameter than the portions 17 and separated by radially inward projections 20 extending to the circumferential surface of the bore 16 . Each projection 20 has stop faces ' and 20 " .

The arm 10 is supported on the body portion 21 of the rotary water sprinkler, as hereinafter described, by a boss 22 which is detachable from the arm. The boss 22 is shown in Figures 1 arid k and comprises a cylindrical portion 23 1 bored to fit on to a bearing pin Zh extendin co-axially 2 from the body portion 21 of the sprinkler. The lower end 3 of the cylindrical portion 23 carries four integral tongues h 25 each having a part 26 of complementary shape to the undercut recesses 18 and a part 27 at the extreme lower 6 end of the portion 5 having a radially outer surface for 7 fitting into the intermediate counterbore portions 19· 8 To attach the boss 22 to the arm 10, the tongues 25 9 are axially-aligned with counterbore portions 17 and the lower parts 27 of the tonues 25 are inserted into the 11 counterbore portions 19 with one side face of each tongue 12 5 adjacent the face 20' of a projection 20. The boss 13 is then turned clockwise relatively to the enlargement 13 li(. of the arm as viewed in Figure 3 until the other side face of each tongue 25 has abutted the face 20" of a projection 16 20. In this position, the part 26 of each tongue 2 is 7 engaged with an undercut recess 18 and the boss cannot 18 be withdrawn axially from the arm. To release the boss jo, it must be turned in the anti- clockwise direction until each tongue engagesthe face 20' of each projection 20. 21 When the boss 22 has been attached to the arm 10 as 22 described in the immediately preceding paragraph, the arm 23 and boss are mounted on the sprinkler body portion 21 by l. passing the boss 22 over the bearing pin 2k. The sprinkler 2 per se is not part of this invention but its construction 2 and operation will be briefly described to explain the Y need for providing an arm having a detachable boss in 28 accordance with the present invention. Referring to Figure 5 1 the sprinkler body portion 21 is attached to a water inlet 0 tube 28 and is rotatable together with the tube, the latter 1 being1 supported in a pipe union 29 attached to a stand-pipe, 2 not shown. The arm 10 is rotatable relatively to the body 3 portion 21 by virtue of the boss 22 being mounted on the k bearing pin 2k . A bearing thrust washer 30 is positioned between the boss 22 and the body portions 21. The boss 22 6 is retained on the bearing pin 2k by a collar 31 held on 7 the bearing pin 2k by a removable D-ring 32. A torsion 8 spring 33 acts between the boss 22 and the collar 31· 9 The spring 33 is housed within a cap 3^ which makes a snap fit with the tongues 25 adjacent their upper ends. The 11 body portion 21 of the sprinkler has a throughway 35 12 communicating with the water inlet tube 28 and leading 13 to an outlet containing a nozzle 36 for directing a jet Ik of water against the spoon-shaped head 11 of the arm.

The body portion 21 also carries an anvil-like arm 37 16 against which the tail portion 12 of the arm 10 is biased 1 by the torsion spring 33· 18 In operation, the jet of water issuing from the nozzle 1 36 strikes the head 11 of the arm 10 and causes the latter to turn relatively to the body portion 21 against the 21 bias of the spring 33· when the torsional deflection of 22 the spring 33 reaches a predetermined value, the spring 23 will cause the arm to turn in the reverse direction until 2k the tail portion 12 strikes the anvil 37. This causes the 5 body portion 21 and the arm 10 to be turned bodily about 2 the axis 15 through an angular increment. In this way 27 the body portion 21 will gradually be turned about the 28 axis 1 and an area of ground or crops will be watered.

As is well-known, the sprinkler may have sectoring mechanism, whereby the body portion 21 will be turned in angular - - " increments throug a predetermined sector only and then returned to its starting position.

Due to the relative rotational movement between the boss 22 and the washer 30 and the bearing pin 2k, the boss may become worn and require replacing. Alternatively, the arm may become damaged and require replacing. By making the boss 22 detachable from the arm 10, instead of integral with it, as hitherto, only the boss or the arm require replacing. The boss 22 may be made fro a material having better wearing characteristics than the arm 10.

The boss '22 may be made of a standard . size and shape for fitting into arms having different shaped heads and therefore this invention provides for ready interchange of swing arms.

The second swing. arm and its detachable boss as shown in Figures 5 to 7 are similar in general respects to the swing arm and boss shown in Figures 1 to k. The arm kO has a central enlargement ^l of circular shape, as viewed in plan. The portion l has a co-axial bore k2 having in its upper face an undercut co-axial annular counterbore k3t instead of the circumferentially- spaced recesses of the first example. As before the boss1 kk has four circumferential spaced tongues k^ , each having an extension k6 of shape complementary to the undercut counterbcrre k}" . The counterbor has four axially- extending slots k7 formed in it to provide access for the extension h6 to the undercut portion thereof. i A stop pin ^8 extends upwardly from the end face k9 of the counterbore, as shown in Figure 7· To assemble the combined arm and boss, the boss is arranged with its tongues k6 in axial alignment with the slots ^7 and the tongues are inserted into the slots until the lower ends of the tongues abut the end face 9 of the counterbore0 The boss is then turned relatively to the arm until the extensions h6 are engaged within the undercut counterbore which will prevent the separation of the boss from the arm. The boss cannot be turned too far as one of the tongues $ will engage the stop pin k8. The boss has to be turned in the reverse direction to bring the tongues $ into axial alignment with the slots 7 before the boss can be separated from the arm.

Claims (6)

C L A I M S

1. . A rotary ater sprinkler of the kind comprising an inlet pipe, a body portion 'rotatably mounted on said inlet pipe, a nozzle-amounted on said body portion and communicating therethrough with said inlet pipe, a swing arm rotatable relatively to the body portion into and out of impacting engagement therewith and having a spoon-shaped head which, during operation of the sprinkler,- is impinged by a jet of water from said nozzle to effect said impacting engagement and a helical torsion spring acting between the swing arm and the body portion in opposition to the turning of the swing arm by said jet of water, the sprinkler including a pivot pin on said body portion, a boss removably mounted on said pivot pin and having a flange against which one end of said torsion spring engages, a collar removably secured to said pivot pin to hold said boss axially thereon and providing an abutment for the other end of said torsion spring, and intererigaging surfaces on said boss and said swing arm supporting said swing arm from said boss and locking said swing arm to said boss for rotation therewith.

2. . A rotary water sprinkler as claimed in Claim 1 including a detachable cap engaging the flange on the boss and enclosing the boss, the torsion spring, the collar and the pivot pin.

3. · A rotary water sprinkler as claimed in Claim 1 or 2 including locking means comprising circumferentially spaced tongues on the arm or the boss and arranged to pass throug corresponding axially extending throughways on the other of the arm or the boss, the throughways giving access to an undercut recess in which said tongues when located in the throughways are insertable by relative circumferential movement between the arm and the boss to prevent the boss and arm from being separated axially .

4. The combination of a swing arm for a rotary water sprinkler and a removable boss for a rotary water sprinkler as claimed in any one of the preceding claims.

5. . A swing arm for a rotary water sprinkler as claimed in any one of Claims 1 to 3 » the swing arm having locking ■ means interengageable with locking means—on- the— oss—removable from the swing arm.

6. . The combination of a swing arm and a removable boss therefor, for a rotary water sprinkler, constructed and arranged substantially as described herein and shown in. Figures 1 to k or Figures 5 to 7 of the accompanying drawings. y£. E. MULFO D Eorney for Applicants