US2140954A - Regulating mechanism - Google Patents

Description

Dec. 20, 1938. D. H. FRAZEE 2,140,954

REGULATING MECHANISM Filed June 29, 1936 IN VENTOR.

DON/PHAN H. FPAZEE ATTORNEY.

Patented Dec z o, 1938 UNITED STATES PATENT- OFFICE REGULATING MECHANISM Application June 29, 1936, Serial No. 87,862

'2 Claims. (Cl. 137153) My invention relates to regulating mechanism, and more particularly to'mechanism of this character which will effect delayed action in the operation of control means such as valve means for controlling flow of fluid to an oil burner or the like.

In fluid circulating or feeding systems wherein the flow of fluid is controlled by the operation of suitable valve means, it is sometimes desirable to obtain delayed action in the operation of such valve means either in opening or closing. For example, in an oil burner fuel supply system where the device of my invention has been found particularly applicable, it is desirable in starting the burner tov avoid feeding thereto a full quantity or supply of fuel oil during the initial period of ignition of the oil. Should such full quantity of 011 be fed to the burner initially, there is danger of a minor explosion or puffing occurring upon 20 ignition thereof because the ignited oil tends to blow out through all available openings, and even backfire through the burner itself.

Most fuel oil systems of the character related include a constant volumetric supply pump which supplies to the burner a substantially fixed quantity of oil per unit of time. Usually when the pump is first operated, either automatically or by hand, to supply the oil to the burner, a valve is also simultaneously operated to control the flow to the burner; Unless the valve is gradually opened so that full opening thereof is delayed for an interval of time, the full supply of oil will be initially fed to the burner thereby creating th undesirable conditions discussed. My invention is designed to overcome the above described diificulty, and has as its objects, among others, the provision of improved:

1) regulating mechanism for obtaining delayed action in the operation of control means such as that employed for controlling flow of fluid;

(2) mechanism, of the character related, which is of simple and economical construction, and which operates easily;

(3) mechanism, of the character related, which is operated by the fluid itself; and

(4) which at the same time will be unaffected by variations in the viscosity of such fluid.

In general, the device of my invention comprises dashpot mechanism formed of cooperating extensible and contractible fluid containing chambers communicating with each other through restricted passageway means which allows flow of the fluid therethrough. Such chambers can be conveniently formed of opposed flexible bellows. Upon application of pressure to the end of one of such bellows, it is caused to contract or be compressed. This results in flow of fluid through the restricted passageway means to expand the other bellows which has power transmitting means for connection to the mechanism to be operated. As a result of restricted flow of fluid through the passageway means, delayed action is obtained in such operation.

Casing means is provided about the extensible and contractible chamber to which the pressure is applied, so as to enable fluid to be employed for applying such pressure. In use, for example, in an oil burner oil supply system, the casing means is connected in the system to receive oil under pressure, and the dashpot mechanism is connected to valve means for controlling the flow of oil to the burner. Upon initial circulation of oil in the system by the usual pump or other suitable means, the dashpot will thus be actuated and will effect delayed action in the transmission of power to the valve means.

Reference will now be made to the drawing for a more detailed description of the invention. In the drawing:

Fig. 1 is a vertical cross-sectional view of the regulating mechanism of my invention, taken through the center line thereof.

Fig. 2 is a schematic representation of a conventional oil burner and. oil supply system therefor, illustrating the connection of the regulating mechanism.

The regulating mechanism-l of my invention is formed of opposed corrugated tubes or bellows 2 and 3, of any suitable resilient metal. Lower bellows 2, in Fig. l, is sealed at its lower end by piston plate 4 to which the bellows is secured by suitable means such as brazing. At its upper end. bellows 2 is sealed by brazing to a stationary plate 6 having a neck I fixedly screwed into a second plate 8 which is fixedly mounted in a manner to be subsequently explained. Upper bellows 3 is sealed at its lowerend, in Fig. 1, to plate 8 by means of brazing, and at its upper end it is sealed by brazing to movably mounted cupshaped piston member 9. Plate 6 is formed with an orifice ll extending through neck 1 thereof, in which neck is screw threaded ferrule l2 having restricted orifice l3 of predetermined size. The stepped portions in ferrule l2 are formed merely for convenience, to facilitate formation of the restricted orifice l3 at the end thereof during the drilling operation.

Bellows 2 and 3, it will be seen, form extensible and contractible chambers l4 and I6, respectively,

which are sealed against entrance of fluid therein from exteriorly thereof. Such chambers are separated by partition means formed by plates 6 and 8 but are. however, in restricted communication through a passageway such as oriflce 13 extending through such partition means. The chambers are completely filled with a suitable non-viscous fluid, i. e. a fluid the viscosity of which does not materially change under normal variations in temperature. A suitable fluid of this character is kerosene, although glycerine or water can be employed if so desired. Such fluid is introduced into the chamber through an orifice formed in piston plate 4 which is subsequently sealed by plug 11.

A protective cover I8, secured to plate 8, is positioned over the'upper bellows 3 in Fig. l, and is provided with bushing member 18 in the top thereof. Rod 2! fixedly secured to piston member 9 of bellows 3, is slidably mounted in bushing 19, and forms part of the means for connection to the device or mechanism to be controlled or actuated by the regulating mechanism. Such means also includes link or lever 23 pivotally mounted in ears 24 fixedly secured to cover i8, and adapted to be moved by rod 2| upon expansion of bellows 3 from the position shown in Fig. 1. Cover I8 and the partition means including plate 8 are fixedly mounted when the mechanism is installed.

From the preceding description, it will be apparent that if pressure is applied to piston member 4, bellows 2 will be contracted or compressed. This results in fluid flowing through the restricted orifice G3 to expand bellows 3 and move piston member 9, to actuate the means 2| and 23 for connection to the control device adapted to be operated by the regulating mechanism. However, because of the resistance to flow of fluid from chamber 14 into chamber I6, which the restricted orifice i3 provides, it will be observed that piston member 9 will not be moved to its fullest extent, immediately upon application of pressure to piston member 4. It will be moved gradually or slowly, depending on the size of orifice l3, until piston member 9 is abutted against the under side of the top of cover 18.

- Thus, the described mechanism forms a dashpot,

and as a result, the device to be controlled and to which lever 23 is adapted for connection, will be operated or actuated with a delayed action.

In this connection, orifice 93 may be made of any pre-selected size to determine the rate of flow of fluid therethrough, and thereby fix the time desired for the delayed action. When the connection means, including lever 23, is moved to its fullest extent to the dotted line position shown in Fig. 1, it will be maintained in such position as long as the pressure is maintained against piston member 4. However, as soon as the pressure against piston member 4 is withdrawn or relieved, spring 26, attached to link 23 and to cover l8, will restore the parts to their original or inoperative position, by causing compression or collapsing of bellows 3. This results in reverse flow of-fluid through restricted orifice l3 and consequent expansion of bellows 2.

Any suitable means may be employed to apply the pressure against piston member 4. Inas piston member 4. For this purpose, a fluid tight chamber or casing is formed about bellows 2 of the extensible and contractible dashpot chamber 14, by means of casing 21 and partition plate 4 to which casing 21 is secured by the same bolts 2! which hold cover 18 to partition plate 3. A suitable gasket 3| is placed between partition plate 3 and casing 21 to make the structure leak proof. Fluid under pressure is introduced into casing 21 through the conduit connection at 32. It should be observed that the fluid under pressure introduced into casing 21, cannot enter the extensible and contractible dashpot chambers 14 and I! because such chambers, as has been previously explained, are completely sealed against entrance of fluid from the exterior thereof. Thus, the fluid entering casing 21 acts only by pressure against the outside of piston member 4 to provide the action pointed out above.

Although the described regulating mechanism may be employed any place where it is desired to obtain delayed action in the operation of a control device, such as a valve for controlling flow of fluid, I have found such mechanism to be, particularly successful when employed in an oil burner fuel supply system to obtain delayed action in the initial opening of a valve for controlling the supply of oil to the burner. In such system, it is desirable when operation. of the burner is initiated, that the whole or full amount of oil be not immediately supplied to the burner for ignition, to avoid backfiring or puiilng which might otherwise occur.

Fig. 2 illustrates schematically a conventional type of fuel oil supply system for an oil burner, in which the regulating mechanism l is employed. Such regulating mechanism is fixedly mounted on the burner casing 43 having the primary air control shutter 4| and fuel inlet conduit connection 42 to the burner nozzle which may be of the conventional rotary atomizing cup type. A constant volumetric supply pump 43 is employed to pump the fuel oil from any suitable source (not shown) to the burner conduit connection 42, through conduit 44 having control valve 46 of any suitable construction for controlling the flow of oil upon operation of the pump. Such control valve is usually mounted directly on burner casing 40. In such type of system, pump 43 usually supplies more fuel than that required by -the burner to insure that the burner always has an ample supply of fuel; the excess quantity of fuel being bypassed back to the suction side of the pump by means of bypass conduit 41 connected to conduit 44 beyond valve 46, and to the suction side of the p p.

To obtain actuation of regulating mechanism 1, conduit connection 32 of casing 21 is connected to the delivery side of pump 43 ahead of valve 4B, by means of conduit 48. Thus, the regulating mechanism will be actuated by the fuel oil pressure created by pump 43, immediately upon initiation of operation of pump 43 when it is desired to start the burner either automatically or by hand. When this occurs, delayed action in the opening of valve 46 which controls the fuel supply to the burner, is obtained by connection thereof with link 23 through suitable linkage mechanism 49. As it is desirable to regulate the amount of air to the burner in accordance with the quantity of fuel oil supplied thereto, primary air shutter 41 is connected to the regulating mechanism link 23 by means of link 51 pivotally connected to bell crank 52 which is pivotally nected to link 54 in turn pivotally connected to link 23. Preferably, bell crank 52 is also connected by chain 55 to the secondary air supply (not shown) of the burnerfor controlling the draft to the fire box. Thus, when control valve 46 is opened with the delayed action by the regulating mechanism 1 to provide for gradual feeding of oil to the burner upon starting thereof. both the primary and the secondary air supplies to the burner will also be gradually opened in correlation with theopening of the fuel oil valve 46.

It is thus seen that I employ the pressure of the fuel oil itself, to actuate the regulating mechanism of my invention, which in turn operates the fuel oil control valve with a delayed action. Even though this is done, viscosity variations in the fuel oil, which usually varies widely in viscosity because such oil is viscous and is affected by temperature changes, will not affect the rate of opening of the valve 46 as controlled by the size of restricted orifice l3. This is so, because as was previously explained, the fluid within the expansible and contractible dashpot chambers l4 and I6 is of nonviscous nature, and is different from that of the fuel oil and does not come in contact therewith. Furthermore, since the fluid in the dashpot mechanism is sealed therein, the dashpot action will always be positive and substantially the same because such fluid cannot leak out of chambers I4 and I6 when the dashpot is operating. Although the pressure of the fuel oil itself will vary upon changes in viscosity, such variations in pressure will have a negligible effect on the pressure applied to piston member 4 because conduit connections 48 and 44 are of comparatively large size.

Usually, ferrules I 2 having orifices l3 varying in size are manufactured; the ferrule being selected in accordance with the capacity of burner with which the regulating mechanism is to be employed, and also the rate of delayed action desired in the operation of the fuel oil control valve 46 for such burner, which for most practical purposes may be from 15 to 20 seconds.

I claim: v

1. In a system for feeding liquid the viscosity of which varies with variations in temperature, including means for supplying the liquid under ressure and valve means for controlling the flow of said liquid; mechanism utilizing the pressure of the liquid controlled by said valve means for obtaining delayed action in the operation of said valve means upon initial operation of said liquid supplying means including power transmittng dashpot means consisting essentially of extensible and contractible chambers containing liquid which is sealed therein, said chambers being in communication through restricted passageway 1 means through which the liquid in said chambers can flow upon application of said liquid pressure to one of said' chambers, the restriction of such passageway means being small enough to resist the flow of the liquid in said chambers therethrough to an extent sufficient to cause delayed expansion of a second of said chambers upon application of said liquid pressure to said one of said chambers, the liquid in said chambers being such that the rate of power transmission by said chambers is substantially unaffected by normal variations in temperature, a casing about said one of saidchambers for receiving the controlled liquid under pressure, a conduit for conveying the controlled liquid into said casing, and a power transmitting connection between said second chamber and said valve means.

2. Regulating mechanism for transmitting communication through restricted passageway means through which the liquid in said chambers can flow upon application of pressure to one of said chambers, the restriction of such passageway means being small enough to resist the flow of the liquid in said chambers therethrough to an extent sufllcient to cause delayed expansion of a second of said chambers upon application of said pressure to said one of said chambers, the liquid in said chambers being such that the rate of power transmission by said chambers is substantially unaffected by normal variations in temperature, a casing about said one of said chambers to confine a fluid under pressure to enable application of said pressure tosaid one of said chambers, and a power transmitting member connected to the second of said chambers and adapted for connection to said control device.

DON'IPHAN H. FRAZEE.

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