US2276424A - Automatic hydraulic safety lock for oil burners - Google Patents

Description

March 17, 1942. slVERSEN f 2,276,424-

AUTOMATIC HYDRAULIC SAFETY LOOK FOR OIL'BURNERS Filed Aug. 23, 1940 zai FIE-1- 1 IN V N TORS k 100 v /e. K ,we'esew JOHN. D. .S'T/ GEN ATTORNEY)- Patented Mar. 17, 1942 UNiTED STATES- AUTOMATIC HYDRAULIC SAFETY LOCK FOR OIL BURNERS Ludvig K. Siversen, San Francisco, and

John D. Stigen, Oakland, Calif.

Application August 23,1940, Serial No. 353,898

Claims. 7 (01.158-73) The invention, in general, relates to safety apparatus. More particularly, the invention relatesto automatically operating mechanism forpreventing fires and personal injuries that may otherwise occur from escaping hot oil during the operation of repairing or thecleaning of oil burner nozzles.

It is probably well known that many attempts have heretofore been made to reduce the likelihood of property losses or damage and personal injury resulting from careless handling of oil burners. Too often careless operators and repair men have dismantled an oil burner head to obtain access to a clogged atomizing nozzle without insuring that the fluid supply line is entirely shut off with the result that considerable damage has occurred from fires arising from escaping hot oil, as'well as painful injuries to workmen. A number of mechanically operable devices have been developed and installed heretofore in an endeavor to obviate these occurrences but these devices, in general, are or become defective, inoperative or are frequently removed during a re-' pair job and inadvertently not replaced so that the danger alluded to is as potentially present as burner head while the fluid line is open.

A still further object of the invention is to provide an improved lock for oil burner heads which is mechanically independent of the burner elements and which can not be tampered with or inadvertently be dismantled or removed when dismantling the burner head for repair of the burner atomizing nozzle.

Another object of our invention is to provide an improved automatically actuated lock for oil burner heads which is inexpensive to manufac- 4 ture, install and maintain.

Other objects of the invention, together with some of the advantageous features thereof, will appear from the following description of a preferred and one modified embodiment of our invention which are illustrated in the accompanying drawing. It is to be understood that while a preferred and a modified embodiment of our improvement are depicted in the annexed drawing, we are not to be limited to the precise embodiments shown, nor to the precise arrangement of the various elements of the combination, as.

our invention, as defined inthe appended claims, can be embodied in aplurality of variety of forms.

Referring to the drawing:

Figure 1 is an elevational view, partly in section, of a preferred embodiment of our invention.

Figure 2 is a view taken on the line 2-2 of Figure l. r

Figure 3 is a view taken on the line 3-3 of Figure '1.

Figure 4 is a side elevational View of a portion of the assembly and illustrating one type of take-off for by-passing a portionof the fluid supply to the burner.

Figure 5 is an enlarged view, partly in section,

of a modified embodiment of our invention.

In its preferred form, the automatic hydraulic safety lock of our invention, for application to oil burners, preferably comprises the combination with a burner head, a valve-controlled fluid line for supplying fluid to said head, and a movable member for removably retaining said head in operative position, of an expansible element in communication with saidfluid line, a pawl connected to said element, and a ratchet on said member; said expansible element being responsive to fluid pressure in said line to hold said pawl in engagement with said ratchet and thereby pre-' vent movement of said member and dismantling of said head while said fluid line is open.

While the improvement of our invention is entirely appilcable to any fluid system for positively locking elements thereof together to' prevent or avoid dismantling of elements while the fluid line is open, it is especially suitable for adaptation to oil burners, whether of the marine type or stationary, to prevent property losses or damages, or injury from escaping hot oil, and

we have, accordingly, illustrated our invention and shall described the same in the oil bume environment.

In Figures 1 and 3 of the drawing, we have ilby reference to Figure 1 of the drawing, that sired. The entire burner head, assembly is fastened to the burner front on the boiler, all not shown, by means of a. clamping bracket |8. The

burner head comprises a hollow body defining an interior chamber 2| which is in communieation not only with a burner head inlet 22 but also with its outlet 23 formed in an internally threaded boss 24 on the head. Hot oil is supplied to the burner head H from a source, not shown, by means of a pipe 26 which communicates with an axial bore 21of yoke bushing l3 that leads to bushing outlet 28 which is in registry with burner head inlet 22. A suitable valve 29 is interposed in pipe line 23 for controlling fiuid fiow therethrough and into the burnerhead, the valve having a stern 3| extending therefrom which conveniently carries a handwheel 32 for turning the valve to open and closed positions, or to any desired position thereby to regulate the flow of oil and pressure in line 26. The hot oil delivered to burner head H is supplied to the oil burner through a tube 33 which is externally threaded at the burner head end thereof for removable engagement with the internally threaded boss 24 of the head, and which carries an atomizing nozzle 34 at the burner end thereof, all as shown in Figure 3 of the drawing.

In accordance with our invention, an automatically operating hydraulic safety lock is combined with the burner head H and jacking screw I4 for positively locking the head against removf al from the supporting yoke l2 while-the valve of the oil supply line 26 is open. Our improved lock preferably comprises an element 4| which is movable in response to variations of pressure in the oil supply line 26, a pawl 42 connected to or carried by movable element 4|, and a ratchet 43v on the jacking screw |4 so disposed thereon as to be in l alignmentwith the pawl 42 when the jacking screw has been moved so that its inner end is in engagement with the burner head H and is holding the head in operative position. In jthe'preferred embodiment of our invention, the-element. comprises a bellows which is mounted within a hollow, generally cylindrical portion of a body 44 and which defines an expansion and contraction chamber 4|A. In order to obtain ready access to bellows 44 whenever desired, the body 44 is provided with a removable screw cap 46. The chamber 4|A conveniently is closed at the bottom thereof with a sealing plate 41 having an internally threaded socket for threadedly receiving the inner end of the pawl 42, and the upper end of the chamber MA is closed with a sealing plate 48having a flange 49 bearing against the inner surface of screw cap of the body 44. In order to place the expansible and contractible element 4| into communicationwith, the fuel supply line 26, we form the sealing plate 48 of the chamber 41A with a passage 5! therethrough and provide a bypass conduit. 52 leading from the supply line 26 between the valve of the line and the burner head H to thepassage'E-l of the sealing plate 43 of expansion chamber 42A. Suitable pipe fittings 53 and '54,. respectively, are provided for establishing communication between the pipe line 28 and the conduit 52 and between the latter and expansion chamber 4|A through passage 5| of thesealing plate 43 of the chamber. In the preferred embodiment of the invention, wherein the safety lock is shown combined with a typical burner head assembly, the by-pass conduit 52 is connected directly to the yoke bushing 13. If necessary or desirable, the by-pass 52 may be placed in communication with the oil supply line 26 through a T-fitting 53A interposed in the line between the valve and burner head I, as particularly illustrated in Figure 4 of the drawing.

It is to be understood that the body 44 which carries the expansible and contractible element 4| is supported adjacent to the jacking screw l4 so that the pawl 42 carried by the expansible element will be aligned with the ratchet 43 of the jacking screw. To this end, the body 44 may be mounted on any suitable support or it may be supported directly on the yoke l2, as shown, by providing a bracket 56 on the body 44 and a cooperating bracket 51 on the yoke, the two brackets being fastened together by means of suitable screw-bolts 58. It is clear, of course, that the yoke I2 and body 44 can be cast as an integral structure, if desired, with the body 44 being disposed substantially vertically.

In accordance with our invention, means are provided for contracting element 4| whenever the valve of oil supply line 26 is shut off, such means being operable to permit the expansion of the element 4| upon opening the supply line 26 to any extent. This means preferably comprises a coil spring 6| which is confined between the bottom closure plate 41 of element 4| and the bottom of a supplementary chamber 62 formed in the body 44 below the element 4|, the spring being conveniently coiled around an enlarged portion of the stem of pawl 42. The tension of spring Si is of such value that, with the fluid supply line 26 closed, the spring urges the bottom closure plate 41 of the element 4| upwardly to hold the pawl 42 out of engagement with the jacking-screw ratchet 43. Thus, with supply line 26 closed and no pressure in by-pass 52 or in element 4|, the jacking-screw l4 may be rotated freely in either direction since the pawl 42 has been lifted from ratchet 43 by reason of the lifting of closure plate 41 of the element 4|, which carries the pawl. line 26 to any extent, by turning of hand-wheel 32 of the valve, the oil pressurein the line is communicated to bypass 52 as well as to the chamber 4|A of element 4| to expand the same and thereby compress spring 6|. The expansion of element 4| and compression of spring 6| effects a lowering of closure plate 41 and also of the connected pawl 42 to force the latter into firm engagement with ratchet 43, thus preventing the jacking-screw M from being unscrewed as long as pressure remains in the expansion chamber 4 LA. It may be observed, however, that the outer end of pawl 42 is so formed and so engages ratchet 43 that the jacking-screw l4 can be tightened while the line is open and pressure applied 0n the element 4!, so that the burner head II can be tightened against yoke bushing |3 to avoid possible leakage of oil at this joint, as

clearly shown in Figure 2 of the drawing.

. While we have stated that we preferably employ a contractible and expansible element, such as the bellows 4|, to raise and lower the pawl 42,. it is clear that any other suitable means for thispurpose can be employed for movement in re- Upon opening supply provement as defined in the appended claims. In Figure of the drawing, we have illustrated one modified embodiment of our invention exemplifying such equivalent means in so far as actuation of the latching pawl is concerned. In this modification, our automatically operating hydraulic safety lock for oil burners preferably includes a pawl Hi2 which is movably mounted in a hollow body I M and which variably projects therefrom for engaging and disengaging a ratchet secured to the burner head jacking-screw of an oil burner head assembly, all not shown in this view. The mounting of pawl I42 is preferably effected by disposing a coil spring IISI in a generally cylindrical chamber I 62 within the body I 45 and providing an enlarged portion I53 on the stem of the pawl, the enlarged portion having a flange I54 thereon engaging the walls of chamber I62. We also provide an enlarged head I65 on pawl I42 which seats on the flange I64, the coil spring being confined between the bottom of chamber I62 and the lower face of flange I64 and having such tension that it normally holds the pawl free of the jacking-screw ratchet, not shown, when the fluid supply line to the burner head, also not shown, is closed with no pressure on the line.

In order to Compress spring ISI and move the pawl I42 downwardly to engage the jackingscrew ratchet, we preferably provide a flexible diaphragm I56 which is flexed in response to fluid pressure in the fluid supply line which is communicated to the interior of body I44 through a by-pass from the fluid supply line, not shown,

and pipe connection Ilia in communication with the interior of body IN. We also preferably provide, in association with the flexible diaphragm, means bearing upon the enlarged head I 65 of the pawl I IZ and movable by the flexing of diaphragm IE5. To this end, and as illustrated in Figure 5 of the drawing, the diaphragm IE6 is securely seated on an interior annular shoulder I61 of the body M4 by means of a body closure cap I68 and suitable screws IfiQ which pierce the diaphragm. The flexible diaphragm spans an interior chamber of body H34 and divides the chamber into an upper compartment III and lower compartment I72. The closure cap I58 of body I44 is formed with an internally threaded inlet I73 communicating with upper compartment III as well aswith pipe fitting I54 leading to compartment III so that when the fluid supply line is open pressure is communicated to such compartment to flex diaphragm I66. In accordance with our invention, this modification also includes a plurality of dogs I'M which, conveniently, may be three in number spaced approximately 120 apart with their inner ends resting in an annular recess I16 formed within the body I44 and with their outer ends resting upon the top of the head I65 of pawl I42. This arrangement provides, in effect, a pivotal mountin for each of the dogs I'I I. The modification depicted also includes a plate II'I disposed in compartment N2 of body I44 between the flexible diaphragm I66 and the dogs I74, the plate having a depending flange I18 resting on the top of the dogs and serving to press the dogs down upon the head I65 of the pawl whenever the diaphragm I83 is flexed inwardly as a result of fluid pressure on the upper side thereof. In other words, when the valve of the fluid supply line to the burner head is opened to any extent, fluid pressure is communicated to the top of the diaphragm I66 through a by-pass and pipe connection I54. This pressure forces the diaphragm I66 inwardly which, in turn, causes the flangeI'IB of plate IT! to pivot the dogs I14 and to depress the pawl ItZ by the pressure of the inner ends of the dogs on the pawl head. Thus, the'pawl I42 is forced into firm engagement with the jacking-screw ratchet so that the screw can not be loosened with the fluid supply open to any extent, and the burner head cannot be dismantled. Conversely, upon closin the fluid supply line, the coil spring IGI urges the pawl I42 upwardly out of engagement with the ratchet of the jacking-screw to pivot the dogs I'M and return the diaphragm I 56 to normal position since there isno pressure on the outer face thereof.

The safety lock of our improvement is not only directly responsive to the pressure in the oil burner supply line but is positive in action and makes it impossible for the burner head to be loosened whatsoever before the oil pressure is completely shut off.

It is to be understood that the appended claims are to be accorded a range of equivalents commensurate in scope with the advance made over the prior art.

We claim:

1. An automatically operable hydraulic safety lock for adaptation to oil burners, said lock comprising the combination with a detachable burner head, a valve-controlled oil supply pipe for delivering oil through the head to a burner, and a jacking-screw for tightening the burner head in alignment with the supply pipe, of an expansible and contractible element incommunication with the oil supply pipe and responsive to the pressure in the pipe to expand said element, means for contracting said element when no pressure exists in the oil supply pipe, a first latching member carried by said element, and a second latching member on the jacking-screw; said first latching member being held free of said sec ond latching member by said means when the oil supply pipe is closed and being urged into engagement therewith by said element when the oil supply pipe is under pressure to any extent thereby preventing loosening of the jackingscrew and removal of the burner head.

2. In combination with a burner head assembly of an oil burner which includes a movable tubular burner head, a supply pipe for delivering oil to the burner head and a jackingscrew for holding the burner head against movement and in communication with said supply pipe, a bellows in communication with the supply pipe, a pawl actuated by said bellows, and a ratchet on the jacking-screw in alignment with said pawl; said pawl being adapted to be moved intoengagement with said ratchet in response to pressure in the supply pipe and in said bellows thereby to prevent loosening of the jacking-screw when the supply pipe is under pressure.

3. In combination with an oil burner head assembly including a burner head, a valve-controlled oil supply pipe communicating with the head and a jacking-screw for holding the head in alignment with the oil supply pipe, a first latching member on the screw, a second latching member supported in alignment with said first latching member, and means responsive to pressure in the oil supply pipe for urging said second latching member into engigement with said first latching member automatically upon opening the valve of the oil supply pipe and for holding said members in engagement while the valve of the oil supply pipe remains open to any extent.

4. An automatically operable hydraulic safety lock adapted to be included in a burner head assembly including a burner head, an oil supply pipe for delivering oil to the burner head and a jacking-screw for tightening and holding the burner head in alignment with the oil supply pipe, a first latching member on the jackingscrew, a second latching member supported in alignment with said first latching member, and means including a flexible diaphragm for moving said latching members into engagement; said diaphragm being in communication with the oil supply pipe and being adapted to be flexed to move said second latching member into engagement with said first latching member when oil under pressure is admitted to the supply pipe.

5. An automatically operative hydraulic safety lock for adaptation to oil burners, said lock comprising the combination with a detachable tubular burner head and a valve-controlled oil supply pipe for delivering oil under pressure through said head to the burner, of a jacking-screw for tightening and holding the burner head in alignment with the oil supply pipe, and means responsive to the pressure in the oil supply pipe for preventing the loosening of said jackingscrew until the valve in the oil supply pipe is closed to shut ofi delivery of oil to the burner head.

LUDVIG K. SIVERSEN. JOHN D. STIGEN.

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