US2070108A

US2070108A - Adjusting device

Info

Publication number: US2070108A
Application number: US544831A
Authority: US
Inventors: Bargeboer Adolf
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-02-02
Filing date: 1931-06-16
Publication date: 1937-02-09
Anticipated expiration: 1954-02-09
Also published as: NL29560C; GB378041A

Description

Feb. 9,1937,- A. BARGEBOER 2,070,108

ADJUSTING DEVICE Filed June 16, 1931 5 Sheets-Sheet 2 /A/ VENTO/Q DOLF BAQEBOEQ A T TQQ/vm@ Feb. 9, 1937, A. BARGEBOER 2,070,108

ADJUSTING DEVICE Filed June le, 1951 i 5 sheets-sheet 5 /A/L/E/v' To@ f) D F 54965505@ Feb. 9, 1937. A.` BARGEBOER 2,070,108

ADJUSTING DEVICE Filed June 16, 1931 5 Sheets-Sheet 4 AToQA/Eys Feb.` 9, 1937. A. BARGEBOER ADJUSTING DEVICE:

Filed June 16, 1931 5 Sheets-Sheetl 5 Patented Feb. 9, 1937 UNITED STATES PATENT OFFICE Application June 16, 1931, Serial No. 544,831 In the Netherlands February 2, 1931 10 Claims.

This invention relates to an adjusting or control device for elements such as valves, electrical contacts and the like, and has generally in view to provide a device of this character which is extremely sensitive in its operation.

According to the invention, a normally straight, elastic leaf element of spring steel or other suitable material has imposed thereon, axially or longitudinally thereof, a practically unvarying load which is substantially equal to the critical collapsing load of the element; i. e., the load under which the internal forces of the element are in equilibrium with the load and have reached their utmost value substantially without bending of the element and which, if exceeded, results in decided bending of the element. By imposing such a load on a normally straight, elastic leaf element it becomes highly stressed and its sensitiveness to ilexure is vastly increased, so that if it is subjected to a separate bending force it flexes in extremely abnormal proportion to the bending force, depending upon its inherent elasticity.

Further, according to the invention, the bending force to which the elastic leaf element is subo jected may have any desired origin. For example, it may originate from a pressure or temperature controlled diaphragm or the like, or it may originate in the element itself, as is the case if the element is, for example, in the form of a bi-metallic strip or of such other inherent nature that it bends in response to variations in temperature. In any event, the element such as a valve, electrical contact or the like to be actuated or controlled is carried by or is connected with the elastic leaf element. It follows, therefore, that since the elastic leaf element flexes in extremely abnormal proportion to the bending force to which it is subjected, the valve, electrical contact or the like is actuated in response to only very slight bending forces and the device therefore operates to perform its work with extreme sensitiveness.

Moreover, by limiting the range of exure of the elastic leaf element, high pressures of the same in its `extreme flexed or bent positions will result from only very slight bending forces to which the element is subjected, which is of manifest beneilt and importance in many uses of the device. The elastic leaf element is most sensitive to ilexure if the axial load imposed thereon corresponds exactly to the critical collapsing load of said element. However, said element is highly sensitive to flexure if the axial load imposed thereon 1s in the immediate neighborhood of its critical collapsing load, whether slightly above or below the critical collapsing load,

The invention will bemore fully explained with reference to the accompanying drawings, illustrating some embodiments by way of example,

Fig. 1 is a diagrammatic View of a pressureregulator according to the invention. 5

Fig. 2 illustrates an electric excess current cutoff device made in accordance with the invention.

Figs. 3, 4 and 5 show an electric temperaturecontrolling device in two vertical longitudinal sections perpendicular to each other, and in cross 10 section, respectively.

Fig. 6 shows, in vertical section, a gas temperature-controlling device.

Figs. 7 and 8 show two longitudinal sections of another gas controlling device of tubular form.

Figs. 9, 10 and 11 illustrate a steam trap in vertical longitudinal, horizontal longitudinal and vertical cross sections, respectively.

I is the elastic element consisting of a normally straight flexible strip of steel of suitable length, 20 Width and thickness, clamped by means of a spring 5 between the frame 2 and a member 4 pivoted at 3. Attached to the strip I is a lever 6 which by means of the member 'I transforms the force exerted on the diaphragm 8 into a mo- 25 ment on the strip I.

Connected with the leaf element I by means of a stem 9 is a valve I 0 which is movable between the seats I I and I2 by flexure of the leaf element. The load imposed on the leaf element 30 by the spring 5 is substantially equal to the critical collapsing load of said element, and is maintained practically unvarying due to the considerable length of said spring 5 and to the lever arm 4 through which the spring. operates to load 35 the leaf element. According to the illustrationv in Fig. 1 it may be assumed that a negative pressure exists below the diaphragm 8 so that through the rod 1 and arm 6 the leaf element is subjected 'to a movementl tending to bend it toward the left. 40 Only a very slight force exerted through the arm 6 is required to flex the leaf element in either direction. Therefore, the instant the negative pressure below the diaphragm 8 becomes a positive pressure the leaf element will be flexed to- 45 ward the right.

Fig. 2 illustrates an electric overcurrent safety device according to the invention. I5 is an elastic bimetal strip which, at a certain predetermined or critical temperature, is straight and which ilexes to the right if its temperature exceeds said critical temperature, and to the left if its temperature falls below said critical temperature. The strip carries a contact I8 for cooperation with an insulated contact I'IV which is adjustable .5 i

by means of a screw I8. The strip I5 is axially clamped or loaded corresponding approximately to its criticai collapsing load at its critical temperature between the frame 2 and lever 4 by means of the spring 5 adapted to be adjusted by means of a screw I9 threaded into the lever 4 and bearing on the frame -2. Now if the temperature of the strip is below its critical ternperature its internal movement is such that it bends toward the left and the contact I6 is engaged with the contact I1. If at 20 and 2| the electric current wires are connected through a supply apparatus the current flows through the contacts I1, I6, the strip I5 and the frame 2. In the case of an excessive load the temperature of the strip I5 rises above its predetermined or critical temperature, the internal moment attains the critical value and the strip collapses suddenly into the position shown, producing an instantaneous interruption of the current. By suitably adjusting the screw I9 and the spring 5 it is possible that the strip after cooling does not rebound.

While the ilexure of a bimetal strip under normal conditions at the allowable rises of temperature is but very small, this flexure is increased some hundred times by carrying out the invention and moreover, if desired, instantaneously. For this reason the application as a regulator is also possible. K

Figs. 3-5 show an electric temperature regulator according to the invention in two vertical longitudinal sections, perpendicular to each other, and in cross section respectively.

The elastic bimetal strip I5 is clamped on a block of insulating material 22 and carries at its non-clamped end a contact spring 23 which is just free from an abutment 24. If the temperature is too low contact is made with a contact screw 25 while in the other position the strip is retained by a stop screw 26 provided with an insulated cap. Two lateral springs 21, which are tensioned between the

yokes

28 and 29, serve to axially load the strip I5, while the spring 3l, the tension of which may be regulated by means of a rotatable knob 30 (Fig. 5) serves for the adjustment of the switching-out temperature. 'Ihe said rspring engages a profile piece-rigidly secured to the strip I5, whereby a moment is exerted on the strip I5. The current wires are secured to the

contact screws

32, 32. By suitable choice of the essential values an instantaneous switching in and out ata temperature interval of 1 100 C. may be obtained.

Fig. 6 shows a gas temperature regulator according to the invention.

The bimetal strip I5 is clamped or tensioned by the spring 5 by means of the frame 2 and a lever 4, the tension of the spring being adjustable by means of a screw 33. The strip I5 actuates a valve 35 by means of a valve spindle 34.

The whole is immersed in a liquid chamber of the vessel to be regulated in such a manner that the tube 36 is immersed under the liquid level somewhat more than corresponds with the gas pressure. In thismanner a frictionless tightening is obtained. The spring is in this embodiment adjusted so that the first portion of the closing period when the adjusted temperature is attained, elapses very rapidly and the last portion gradually so that the closing is mainly effected very rapidly and further with apsmall name the temperature is very accurately controlled dependent on the loss of heat to the exterior. This is obtained by adjusting the tension of the spring 5 very close by the collapsing load of the strip and by providing the valve 35 with an elastic tightening surface that is more or less uneven. When adjusting for instantaneous opening in both extreme positions a tightening is obtained on the

seats

31 and 38. 39 indicates a spring` with set-screw 40 to determine the initial moment on the strip I5.

Figs. 7 and 8 show two longitudinal sections of another gas-regulator of tubular form.

The operation is similar to that described with reference to Fig. 4, the axial load however being obtained by a spring 4I acting on a

yoke

42, 43. The bimetal strip I5 supported at one end is at the other end acted upon. by a spring 44 with tension controlling device 45 to determine the moment acting on the strip. Further the strip carries directly the Valve 4B co-operating with the seat 41 located opposite an aperture 48 for the passage of the gas. The whole is enclosed in a tubular casing 49 whereby a gas regulator of very compact construction is obtained.

It appears further that the energy which a bimetal strip at a small change of temperature can produce, is much larger when using the invention, than without axial load. On this result the construction of a thermic motor according to the invention is based. It is thereby possible e. g. to use the strip for the reversal of a valve .or valves dependent on the periodical heating or cooling of the strip. Now, if the reversal acts to desist the origin thereof (i. e. heating or cooling) then the machine operates automatically. This may be applied e. g. to a liquidreturn-device to the evaporators.

In Figs. 9-11 this thought is embodied in a condensing vessel.

Fig. 9 is a vertical section, Fig. 10 a horizontal section and Fig. 11a cross section thereof.

The bimetal strip I5 is tensioned in the frame 52 by means 1of the yoke 5D and the spring 5I attached to the strip. The strip carries a valve v spindle with valve 53 adapted to close upon a seat 54 adjustably secured in a body 55 which is laterally tightened by the flanges 55, carrying the frame 52. The valve spindle 53 lifts during the last portion of its opening stroke the spring support 51 against the force of the tensioned spring 58. 'Ihis spring bears at its other end against a spring support 59, whereby by means of a set-bolt 5I) in a casing 6I the spring tension is adjustable.

Now, if steam enters through 62 the strip I5 is heated and it collapses downwardly at a predetermined temperature (e. g. 100 C.) and closes the valve 53 with a blow on its seat 52. Steam thus cannot escape. Now if condensation water accumulates the whole is cooled and at a predetermined temperature, e. g. 90 C., the valve will be pulled open against the pressure. The water escapes, while the valve closes again as soon as the steam reaches the strip I5.

The great advantage of this construction is that the valve is either entirely open or entirely closed and does not occupy a zero-lap position as in most of the condensing vessels. In the latter case the valve will soon leak. The spring 58 serves to take up the transverse load, which at the moment of opening is exerted by the steam pressure. Moreover an adjusting device may be provided for by exerting a variable initial-mment on the strip as e. g. in the regulators according to Fig. 3 (spring 3|) Fig. 6 (spring 39) and Fig. 7 (spring 44).

Instead of using the spring 58 the valve seat may also be so shaped that on draining a pressure-difference above and underneath the valve body is exerted in such a manner, that a downward pressure on the valve is maintained during the outlet period, which pressure is approximately equal to the pressure on the valve in the closed position. .4

The above described .constructions should be considered as embodiments lof the invention, merely given by way of example. The range, however, is much broader.

I claim:-

l. In an adjusting device, an elongated elastic element loaded longitudinally by a substantially unvarying force approximately equal to the critical collapsing load of the element and laterally by a variable internal moment tending to bend said element, the longitudinal force being independent of said internal moment and being applied longitudinally of the element when the same is straight and coincident with the chord thereof when the element is bent.

2. An adjusting device in accordance with claim 1, wherein said elastic element is a bimetallic strip.

3. In an actuating device, an elongated elastic element loaded by a variable load tending to bend said element and also loaded longitudinally by a substantially unvarying force essentially independent of said variable load and of the amount of bending of said element, said longitudinal force being approximately equal to the critical collapsing load of the elastic element and being applied longitudinally of said element when the same is straight and coincident with the chord thereof when the element is bent.

4. In an actuating device, an elongated elastic element loaded laterally by a variable force tending to bend said element and also loaded longitudinally by a force essentially independent of said variable force and of the amount of bending of said element, said longitudinal force being substantially unvarying and approximately equal to the critical collapsing load of the elastic element and being applied longitudinally of said element when the same is straight and coincident with the chord thereof when the element is bent.

5. In an actuating device, an elongated elastic element subjected to the action of a variable moment tending to bend said element and also loaded longitudinally by a substantially unvarying force essentially independent of said variable moment and of the amount of bending of said element, said longitudinal force being approximately equal to the critical collapsing load of the elastic element and being applied longitudinally of said element when the same is straight and coincident with the chord of said element when the same is bent.

6. In an actuating device, an elongated elastic element subjected to the action of a variable force and of a moment which tend to bend said element and also loaded longitudinally by a substantially unvarying force essentially independent oi' said variable force, of said moment and of the amount of bending of said element, said longitudinal force being approximately equal to the critical collapsing load of the elastic element and being applied longitudinally of said element when the same is straight and coincident with the chord of said element when the same is bent. I

7. In an actuating device, an elongated elastic element subjected to the action of a variable internal' moment and of an external moment which tends to bend saidelement and also loaded longitudinally by a substantially unvarying force essentially independent of said external and internal moments and of the amount of bending of said element, said longitudinal force being approximately equal to the critical collapsing loadr of the elastic element and being applied longitudinally of said element when the same is straight and coincident with the chord of said element when the same is bent.

8. A device of the character described comprising an elongated elastic leaf element, resilient means acting to impose on said element longitudinally thereof when the same is straight and coincident with the chord thereof when the element is bent, a practically-unvarying load which is approximately equal to the critical collapsing load of the element, whereby the sensitivity of said element to flexure is vastly increased, means whereby said element is subjected to a flexing force, and means operable by flexure of said element.

9. A device of the character described comprising an elongated elastic leaf element, means including a spring and a cooperating lever acting to impose on said element longitudinally thereof when the same is straight and coincident with the chord thereof when the element is bent, a practically unvarying load which is approximately equal to the critical collapsing load of the element, whereby the sensitivity of said element to fiexure is vastly increased, meansv whereby said element is subjected to a flexing force, and means operable by flexure of said element.

10. A device of the character described comprising a normally straight, elongated elastic leaf element, resilient means acting to impose on said element longitudinally thereof when the element is straight and coincident with the chord thereof when the element is bent, a practically unvarying loadwhich is approximately equal to the critical collapsing load of the element, means whereby said element is subjected to a bending force, and means operable by bending of said element.

ADOLF BARGEBOER.