US3031210A

US3031210A - Safety lock for oil burners

Info

Publication number: US3031210A
Application number: US9105A
Authority: US
Inventors: Donald E Schott
Original assignee: Babcock and Wilcox Co
Current assignee: Babcock and Wilcox Co
Priority date: 1960-02-16
Filing date: 1960-02-16
Publication date: 1962-04-24
Anticipated expiration: 1979-04-24

Description

April 24, 1962 D. E. SCHOTT SAFETY LOCK FOR OIL BURNERS 5 Sheets-Sheet l Filed Feb. 16, 1960 a BY April 24, 1962 D. E. SCHOTT 3,031,210

SAFETY LOCK FOR OIL BURNERS Filed Feb. 16, 1960 5 Sheets-Sheet 2 FIG.3

INVENTOR.

BYJQJ/ 5 5M i: am 4 14: 1 4.

April 24, 1962 D. E. SCHOTT SAFETY LOOK FOR OIL BURNERS 5 Sheets-Sheet 5 Filed Feb. 16, 1960 INVENTOR. M4 275M April 24, 1962 D. E. SCHOTT SAFETY LOCK FOR OIL BURNERS 5 Sheets-Sheet 4 Filed Feb. 16, 1960 Khw/ gm; 64AM; 1%;4

April 24, 1962 D. E. SCHOTT SAFETY LOCK FOR OIL BURNERS 5 Sheets-Sheet 5 Filed Feb. 16, 1960 FIG."

INVE TOR. wad 2% 3&3 l ,2 l d Patented Apr. 24., l 962 This invention relates to safety lock devices constructed to prevent the manual breaking of a fluid line while the valve, through which liuid is supplied to the line, is open. More particularly, the invention is concerned with a novel safety lock device which is especially adapted for use with an oil burner of the type commonly employed in marine boiler furnaces and acts to prevent the pulling of the burner from the furnace, not only while the oil supply valve is open but also as long as there is oil under pressure in the burner.

Oil-fired marine boiler furnaces are provided with a plurality of burners, all of which are used only when the vessel is to be driven at the highest possible speed, as in emergency. Under operating conditions requiring less than all the burners, those not in use must be pulled from the furnace to prevent their nozzles from being clogged with carbon. In naval vessels, the pulling of oil burners may be of frequent occurrence and, since burners are supplied with oil at pressures ranging from 250 F.

to 300 F. and at pressures as high'as 300 p.s.i., it isv necessary to provide such a burner with a safety lock which prevents the pulling of the burner while the fuel valve is open. Even though the valve may be closed, the burner may contain oil under residual pressure and the device should prevent pulling of the burner until such pressure has dissipated.

The present invention is directed to the provision of an oil burner safety locicwhich prevents pulling of a burner while the valve is open and while there is oil under pressurain the burner. The new lock also prevents accidental opening of the valve, when the burner is not in place.

For a better understanding of the invention, reference may be made to the accompanying drawings, in which FIG. 1 is an exploded longitudinal horizontal sectional view with parts shown in plan, of one form of the new lock and parts of the valve with which it is used;

PEG. 2 is a fragmentary view in side elevation with parts shown in section and broken away of a burner held in place by the new lock;

MG. 3 is a horizontal sectional view of the burner valve of FIG. 1 equipped with the new safety lock and with its parts shown in operative condition;

FlG. 4 is an elevational view of an interlock arm employed in the safety lock of the invention;

FIG. 5 is a sectional view on the lined-5 of FIG. 3;

P16. 6 is a view similar to FIG. 3 with the safety lock shown in inoperative condition;

FIG. 7 is an exploded view, partly in horizontal longitudinal section and partly in plan, of a form of the safety device employed with another form of fuel valve;

H63. 8 and 9 are end views of a valve handle and a ratchet;

FIG. 10 is a vertical longitudinal view showing a burner held in place by the safety lock of FIG. 7;

FIG. 11 is a fragmentary horizontal sectional view through the oil valve of FIG. 10; and

FIG. 12 is a fragmentary sectional view on the line 12-12 of FIG. 11.

The safety lock and valve in the form shown in FIGS. l-6, incl., comprise a housing 20 with an externally threaded inlet 21 having a passage 22 surrounded at its.

inner end by a seat. Flow through the valve is controlled by a valve member comprising a head 23 engageable with the seat and mounted on a stem Mthreaded in a bonnet 25 which forms part of the housing and is held in place in one end of the housing by a bonnet nut 26. The valve housing has an integral outlet extension Zila containing an outlet passage 27 surrounded at its outer end by a seat 28 formed with a circumferential recess, in which a gasket '29 is disposed.

A cylindrical body 31%) forming part of the housing is threaded on the bonnet 2s and has an car 31 extending laterally therefrom. Outwardly beyond the threaded portion, the body is cylindrical and is provided with diametrically disposed aXial slots 32;. At its outer end, the bonnet is of substantially larger diameter than the stem 2 passing therethrough to form a chamber 33, which contains a sealing ring 34 and an annular piston sleeve 35,

, the ring and piston surrounding the stem.

I An interlock arm 36 has a ring 3 7 at one end, which encircles the body Sill. At its outer side, the ring is formed with an internal flange 38 formed with diametrical radial notches 33 A key 3% includes a ring dtl, which encircles the body and is provided with diametrically disposed lugs dda, axial arms 41 lying aligned with and inward from the lugs, and radial ears 42 extending inward from the arms. The arms andthe ears lie within the slots in the body and the ears terminate in front of the piston sleeve 35. At their outer ends, the arms 41 are formed with longitudinal slots and a pair of pawls 4- are pivotally mounted in the slots. A washer 45 surrounds the arms dll inward from the pawls id and the washer has internal ears ida extending into the slots 43 of the arms and a second washer as surrounds the arms and lies against the outer face of the ring 37 of the interlock arm 36. A coil spring 47 encircles the arms and bears at its ends against the washers 4-5, 46. A cover 48 is seated at one end on a circumferential shoulder on washer 46 and extends outwardiy to engage the outer surface of the slotted cylindrical section of the body ill The cover is held in place by a spiral lock ring 4? seated in a groove in the outer surface of the body.

A tubular ratchet 5t} having an enlarged section with external axial ratchet splines 51 surrounds the stem 24 with the "splines lying in position to be engaged by the the other, against a washer 54 seated on the inner end of the enlarged section of the ratchet.

The section 52 of the ratchet is internally slotted at 55 to receive the ends of a key 56 mounted in an opening through the stem 2 and the splined section of the ratchet is formed with spaced internal lugs 57 having cam surfaces 57a lying at an angle to the axis of the stem. A handle 5% is mounted loosely on the stem and is held in place by a washer d? and a nut 68'. The handle is formed with a split hub 61, each section of which is receivable between the internal lugs on the ratchet and has an in clinedv cam surface 62 engageable with a cam surface 57a on the ratchet Ell.

The valve housing 2@ is formed with bosses 63 extending outwardly from opposite sides of the outlet passage 27 and a yoke 64 is pivotally mounted on the ends of the bosses by bolts 65 extending through openings in the arms of the yoke and threaded into the bosses 63. The head of one of the bolts lies in position to be engaged by the arm 31 on the body 12 and prevents the body from being turned off the bonnet. At its outer end, the yoke is provided with a bloss 64a, through which a bolt 66 is threaded, and the bolt is provided with a conical end and an outer section formed with an inner series of short ratchet splines 67 facing in one direction and a second series of long ratchet splines 68 facing in the opposite cannot be turned to loosen the bolt.

direction. A handle 69 is mounted loosely on the'end section of the bolt and is held in place by a washer 7t and a snap ring 71. Inward from the washer, the hub of the handle is hollowed out to form a cavity 72, into which

project pawls

73, 74 mounted in recesses in the walls of the cavity and pointing in opposite-directions. The pawls are acted on by a spring 75 tending to urge their ends into contact with the surface of. the section of the bolt provided with the ratchet splines.

At its free end, the interlock arm 36 carries a fork 76, the legs of which are provided with internal cam surfaces 760. When the arm is swung to the horizontal position shown in FIG. 3, the legs of the fork extend upwardly on either side of the boss 64a on the yoke and lie between the yoke and the inner end of the hub on the handle 69. In this position of the handle, the

pawls

73, 74 make contact with the long splines 68 only and, when the handle is turned clockwise as shown in FIG. 5, the pawl 74 can engage a spline and turn the bolt to tighten it. When the interlock arm is swung downward, the handle can be moved inward along the bolt to place the pawls in operative relation to the short splines 67 and, when the handle is turned counterclockwise, the pawl 73 co-operates with a short spline 67 to loosen the bolt.

The burner comprises a pipe 77 having its outer end threaded into one end of a U-shaped inlet fitting 78, the other end of which is adapted to engage the seat 28 surrounding the outlet passage 27 through the valve housing. The fitting is provided with a conical socket 79 in line with the end of the fitting engageable with the seat and adapted to receive the conical end of the bolt 66. When the pipe 77 of the burner is in operative position, it extends through a collar 86 attached to the valve housing 20 and through a barrel 81 mounted in an opening in the outer front wall 82 of the furnace.

Prior to the insertion of the burner, the head 23 of the .fuel valve has been seated to close the inlet passage 22 by rotating the stem 24 by means of the handle 53. The rotation of the handle is transmitted to the stem through the'cam surfaces 62 on the hub of the handle and the cam surfaces 57a on the ratchet 50. When the head 23 is seated at the end of the inlet passage, further rotation of the handle causes the surfaces 62 and 57a to force the ratchet inwardly along the stem. In such movement, the spring 53 is compressed and moves the key inward along the stem, so that its lugs 40a pass out of the notches 38a on the internal flange of the interlock arm ring. While the pressure is thus applied to the key through the spring 53, the interlock arm can be swung to vertical position to place its notches 38a out of alignment with the lugs 40a on the key and, when the handle is released, the

spring 53 expands and forces the ratchet outwardly, at the same time rotating the handle slightly. Upon expansion of the spring 53, the spring 47, which is weaker than spring 53 and has been compressed during the compression of spring 53, is free to expand and its acts through the washer 45 to move the key outwardly until its lugs 40a strike the surface of the flange 38 on the interlock arm ring. The spring 47 also acts through the washer 45 to hold the pawls 44 in operative position with their ends between the splines 51 on ratchet 50 and preventing rotation of the ratchet and stem 24 in a direction to open the valve. Accordingly, when the interlock arm is in the vertical position, the key lugs 40a cannot enter the arm ring notches 38a, the pawls 44 lock the ratchet 50 against rotation, and the handle 58, which is loose on the stem 24, cannot rotate the stem to open the valve, because the stem is keyed to the immovable ratchet 50.

When it is desired to open the valve to supply oil to the burner, the interlock arm 36 must be raised until the legs of its forked end lie between the bolt handle 69 and the boss'64a at the outer end of the yoke, so that the handle cannot be moved to engage the short splines and thus The movement of the interlock arm to horizontal position aligns its notches 38a with the lug Stla on the key and, as soon as this occurs, the spring 47 moves the key outwardly along the stem with the lugs entering the notches. In such movement of the key, the tails of the pawls 44 strike the inner surface of the end of the cover, which acts as an abutment and causes the pawls to swing so that their ends are disengaged from the splines 51 on the ratchet 50. The outward movement of the key thus disables the stemlocning means by rendering the pawls inoperative and the position of the key, when the pawls are clear of the splines, may, for convenience, be referred to as the disabling position of the key. With the locking means disabled, the handle 53 can be rotated to turn the ratchet and the stem 24 to open the valve.

When the burner is to be pulled, the interlock arm must be swung to vertical position to permit the bolt handle 69 to be moved inward to engage the short splines 67 on the bolt. The arm can be thus moved only when the valve handle 58 has been rotated to seat the head 23 of the valve to close the inlet passage and the handle has been further rotated to compress the spring 53 to move the key 40 along the stem to free the key lugs 46:: from the notches 33a in the arm ring. In such rotation of the handle, the spring 53 is acting to move the key against the resistance of the spring 47. If there is oil under pressure in the valve housing beyond the valve head 23, as, for example, because the head has not been seated tightly or the valve leaks, the oil will flow along the stem and enter the chamber 33 to act on the sealing ring 34 and the piston sleeve 35. The pressure of the sleeve on the cars 42 on the key opposes the movement of the key by the spring 53 and, when the resistance of the spring 47 and the pressure of the oil acting through the piston sleeve 35 are suflicient to overcome the force of spring 53, the movement of the handle 58 to compress the spring 53 and release the key lugs from the notches in the interlock arm will be ineffective for the purpose. As a result, it will be impossible to swing the arm to inoperative vertical position until the oil pressure acting through the piston sleeve has been dissipated. Accordingly, the new safety lock prevents the burner bolt from being loosened to permit pulling of the burner until the fuel valve is closed and thereis no substantial pressure at the outlet side of the valve.

A modified form of valve equipped with the new safety lock is illustrated in FIG. 7 as including a housing 90, in one end of which is received an inlet fitting 91 held in place by a nut 92 and containing an inlet passage 91a surrounded at its inner end by a seat. The housing has integral sections 96a and 9912 serving the purposes of the bonnet 25 and body 30, respectively, and the section 9611 has an internally threaded passage 93 receiving the threaded stem 94 of a valve member having a head 95 which can be engaged with the seat on the end of the fitting to shut ofl flow through the valve. Near its end, the passage 93 is enlarged to form a chamber in which are disposed a sealing ring 96 and a piston sleeve 97 encircling stem 94. The section 90b of the housing has a cylindrical end portion formed with diametrical longitudinal slots 90c.

The ring 98 of an interlock arm 99 is rotatably mounted on section 96b and has a radial slotted extension 100. A key 161 similar to key 40 is mounted within the ring of the interlock arm on the section 90b of the valve housing and it is formed with axial lugs 101a, arms 102 aligned with the lugs and extending axially from the ring, and internal radial ears 103, the arms and the ears lying within the slots 900. The ends of the arms 102 are slotted and pawls 104 are pivotally mounted in the slots. A washer 105 encircles the arms and lies against the flanged end of the interlock arm ring 98 and a spring 106 corresponding to spring 47 encircles the arms and bears at one end against the washer 105 and, at the other, against the washer 107 which encircles the arms and lies in contact with the pawls 104. A ratchet 108 encircles the stern and has a large diametrical section 109 having external ratchet splines 109a and a small diameter section 110. A washer 111 encircles the section 110 of the ratchet and is engaged by one end of a spring 112 corresponding to the spring 53 and bearing at its other end against the cars 1423 on the key. The ratchet has an internal keyway for receiving a key 113 mounted in an opening through the stem 94 and is also provided with internal lugs 114 with cam surfaces 114a corresponding to the lugs 57 with the surfaces 57a.

A handle 115 is loosely mounted on the end of the stem and held in place by a Washer 116 and aunt 117. The handle has a hub formed with spaced sections 118 corresponding to the hub section 61 on handle 58 and having cam surfaces 118a corresponding to the sections 62 on sections 61.

The valve body has a projecting collar 119 open to the interior of the valve body and a coupling member 120 extends into one end of the collar and is held in place by a coupling screw 121 threaded into the end of the coupling member through the other end oi the collar. The coupling member is screwed on the lower threaded end of an inlet 122 on an outlet housing 123 which corresponds to the valve housing extension Zita and contains a passage connected at one end to the inlet 122 and at its other end having a bushing 125. I

A yoke 126 is pivotally mounted on the housing 123 and is formed at its outer end with a boss 126a into which is threaded a bolt 127. The bolt has an outer section with short ratchet splines 128 for loosening the bolt and long ratchet splines 129 for tightening the bolt. A handle 13b is mounted on the end of the bolt and is provided with internal pawls 131 corresponding to the

pawls

73, 74.

A pin 132 is mounted in an opening in the housing 123 and a yoke 133 which forms the second part of the interlock arm is mounted pivotally on the pin. The yoke 13? is formed with spaced arms 134 corresponding to the legs 76 on the interlock arm 36 and having cam surfaces 134a corresponding to the cam surfaces 76a. The yoke is formed with an arm 135 having a roller 136 mounted on a pin in the arm and lying within the slot in the part 100 of the interlock arm.

The burner employed with the valve and lock of FIGS. 742, incl, includes a pipe 137 threaded to the end of a U-shaped fitting 138 containing a passage 139 surrounded at one end by a seat 1411. When the burner is in operative position, it extends through the housing 123 and is held in place with its seat 140 against the end of bushing 125' by the pressure of the bolt 127. When the burner is in use, the yoke 133 is in the horizontal position with its arms 134 between the end of yoke 126 and the hub of handle 139;. When the burner is to be pulled, the valve must be closed, after which the yoke 133 is swung down, the bolt is backed oil, and the yoke 126 is swung down. When the burner tube is removed from housing 123, the entrance to the housing is closed by a pivoted door 141.

The valve and safety lock shown in FIGS. 7-l0, incl, operate in the same way as the first form of the valve and safety lock shown in FIG. 1. When the valve has been closed to permit the pulling of the burner, the key 101 has been moved in a direction toward the valve housing so that its lugs 101a are out of the notches 98a on the interlock arm ring 98. Thereafter, when the yoke 133 forming part of the interlock arm is swung from between the bolt yoke 126 and the handle 130, the notches 98a on the interlock arm ring move out of alignment with the lugs on the interlock arm ring. In this condition of the parts, the ends of the pawls 10 4 lie in the splines 109a on the ratchet 109 and hold the ratchet against movement with the stem in the direction required to unseat the valve.

When the burner is reinserted in the furnace and secured in place by the bolt, the yoke 133 is swung into place between the bolt yoke 126 andthe handle 130 and this makes it impossible to loosen the bolt by the handle. At the same time, the movement of the yoke 133 to horizontal position aligns the notches 99a in the interlock arm ring with the lugs 101a on the key and the spring 106 can then act to move the key in the direction away from the valve housing with its lugs entering the interlock arm ring notches. This movement of the key causes the pawls 1104 to engage the cover and be swung thereby out of engagement with the splines of ratchet 108. The handle 115 may then be turned to open the valve.

When the burner is to be pulled, the bolt cannot be backed 011, until the yoke 133 has been swung to vertical position, and the yoke cannot be swung until the ears of the key have been moved out of the notches on the interlock arm ring. Such movement of the key requires that the stem 94 be turned to compress the spring 112 so that it overcomes the spring 116 and moves the key toward the valve housing. The spring 112 is thus compressed by movement of the ratchet 168 along the stem 94 and such movement of the ratchet requires that the valve member be seated and that the stem be rotated additionally to cause the cam surfaces 118a on the sections of hub 118 on the handle to co-operate with the cam surfaces 114a on the internal lugs of the ratchet to move the ratchet endwise. Any oil pressure in the valve will act through the gasket 96 and the piston sleeve 97 to resist the movement of the key by the spring 112. Accordingly, the yoke 13% cannot be swung to permit removal of the burner bolt until the valve has been closed and pressure on the outlet side of the valve has been dissipated.

It will be apparent that, with both forms of the new safety lock, it is not possible to pull the burner while the oil valve is open or to open the valve accidentally when the burner is out of position. The reason is that, in order to loosen the bolt, and remove the burner, it is necessa1y to lower the interlock arm to permit the bolt handle to be engaged with the short splines on the bolt. However, when the valve is open, the key lugs are engaged in the notches in the arm ring and the arm cannot be lowered. When the valve has been closed, oil pressure in the burner has been dissipated, and the arm has been released from the key and moved to vertical position, the valve cannot be opened until the arm has again been swung upward to permit the movement of the key, which rees the pawls from the ratchet keyed to the stem. As

the upward swinging of the arm must be a deliberate action, accidental opening of the valve with the burner out of position cannot occur.

I claim:

1. An oil burner safety lock, which comprises an oil valve having a housing with an inlet and an outlet surrounded by a seat, and a stem mounted in the housing and movable in opposite directions to open and close the valve, means, including engageable members mounted on the housing and the stem, for locking the stem against valve-opening movement, a key mounted on the housing and movable to and from a position, in which it disables the locking means by preventing engagement of said members, a spring tending to move the key to its disabling position, a burner inlet fitting engageable with the seat to receive oil through the housing outlet, a bolt engageable with the fitting and operable when tightened to hold the fitting on the seat, a mounting for the bolt attached to the housing, separate means for tightening and loosening the bolt, an arm mounted on the housing and having parts engageable with parts of the key and of the bolt-loosening means, the arm being movable between a position, in which it holds the key against movement to its disabling position, and a second position, in which it disables thebolt-loosening means and is held in place by the key when the latter is in disabling position, means for moving the stem, means operable by the stem-moving means at the end of the valve-closing movement of the stem to urge the key away from its disabling position, and means engageable with the key and operable by oil pressure at the outlet side of the valve to resist movement of the key in a direction away from its disabling position.

2. The oil burner safety lock of claim 1, in which the means for'locking the stem against valve opening movement include a ratchet encircling the stern and keyed thereto, the ratchet having external splines, and pawls mounted on the key and engageable with the splines.

3. The oil burner safety lock of claim 1, in which the housing has a cylindrical portion with longitudinal slots and the key is formed with arms entering and movable in the slots.

4. The oil burner safety lock of claim 1, in which the key is movable axially of the stem, means on the housing guiding the key in its movement, and the arm includes a ring encircling the stem and rotatable to and from a position, in which parts on the ring engage parts on'the key and hold the key against movement to disabling position.

5. The oil burner safety lock of claim 4, in which the arm ring has an internal flange with notches and the key has a ring encircling the stem and having lugs movable into the arm ring notches by the spring acting on the key, when the arm ring is in one position, the lugs engaging the fiange, when the arm ring is in another position, and preventing movement of the key by the spring.

6. The oil burner safety lock of claim 1, in which the means for moving the stem includes a handle mounted on the stem and the means for urging the key to inoperative position includes a spring acting on the key and means operable by the handle to apply force through the spring to the key.

7. The oil burner safety lock of claim 6, in which the key includes a ring encircling the stem and having internal ears engaged by the spring compressible by the means operable by the handle and the means operable by oil pressure includes a piston sleeve encircling the stem and engaging the ears.

8. The oil burner safety lock of claim 6, in which the means for locking the stem against valve opening movement include a ratchet encircling and keyed to the'stem and having external splines and pawls mounted on the key and engageable with the splines, the spring which urges the key to inoperative positionbears at oneend on the ratchet, and the ratchet is movable by the handle, when the valve is closed, to compress the spring.

9. The oil burner safety lock of claim 1, in which the means responsive to oil pressure at the outlet side of the valve include a piston sleeve encircling the stem and acted on by oil in the valve housing, the sleeve being engageable with the key.

10. The oil burner'safety lock of claim 1, in which the means for tightening and loosening the bolt include a handle movable along the bolt and having pawls extending in opposite directions and at least two splines on the bolt engageable by respective pawls to rotate the bolt in opposite directions to loosen and tighten it, and the arm has means operative, when the arm has released the key for movement to disabling position, to hold the handle with its pawls out of operative relation to the bolt loosening spline.

11. The oil burner safety lock of claim 10, in which the arm has a fork movable with the arm to a position straddling the bolt and preventing movement of the bolt handle to place one of its pawls in operative engagement with the bolt loosening spline.

12. The oil burner safety lock of claim 1, in which one end of the spring engages an immovable seat, the locking means include pawls pivoted on the key and engageable with a splined member keyed to the stem, and the spring acts at its other end on the pawls to swing them into engagement with the splined member and to urge the key away from the seat.

13. The oil burner safety lock of claim 1, in which the arm is formed of two parts, one part of the arm including a ring encircling the stem and having a projecting lug, the second part of the arm including a pivoted member, and a slot and pin connection between the parts of the arm for causing them to swing in unison.

14. The oil burner safety lock of claim 1, in which the housing includes an internally threaded bonnet, a body formed with an axially slotted cylindrical portion, and an extension integral with the housing and having an outlet passage surrounded by an external seat, and the stem extends through the body and is threaded into the bonnet.

15. The oil burner safety lock of claim 14, in which the bonnet'and body are integral with the housing and the outlet extension is separate from and connected to the housing.

References Iited in the file of this patent UNITED STATES PATENTS 1,625,098 Rudolph Apr. 19, 1927 2,857,128 Stern Oct. 21, 1958 2,876,983 Martensson et al. Mar. 10, 1959 2,919,145 McGraw et al Dec. 29, 1959