US1966720A - Operation modifying means for a control structure - Google Patents

Description

July 17, 1934. M. E. HENNING 1,966,720

OPERATION MODIFYING MEANS FOR A CONTROL STRUCTURE Original Filed Jan. 27, 1930 i afented July 17, 1934 UNETED STATES OPERATION MODIFYING MEANS A CONTROL STRUCTURE Malcolm E. Henning,

Des Moines, Iowa, assignor to Penn Electric Switch 00., Des Moines, Iowa,

a corporation of Iowa Original application January 27, 1930, Serial No. 423,677. Divided and this application May 11,

1931, Serial No. 536,347

2 Claims.

The object of my invention is to provide an operation modifying means for a control structure which is simple, durable and comparatively inexpensive to manufacture.

The present application is a division of my copending application on a control switch structure, Serial No. 423,677, filed January 27, 1930.

Another object of my invention is to provide a specific type of modifying means for a movable member of an automatic control structure, such as a temperature or pressure operated switch structure.

More particularly, it is my object to provide a modifying means in the form of a spring adapted to act upon the movable member and being adjusted by a nut, which is threaded on a control shaft, the shaft being rotatably and non-slidably mounted and the nut being held against rotation by the spring.

With these and other objects in view my invention consists in the construction, arrangement and combination of the various parts of my device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawing, in which:

Figure l is a front elevation of a control structure showing my operation modifying means applied thereto.

Figure 2 is an enlarged sectional view on the line 2--2 of Figure 1.

Figure 3 is a sectional view on the line 3-3 of Figure 2; and

Figure 4 is a perspective view of the operation modifying means, the parts being shown separated.

On the accompanying drawing, I have used the reference numeral 10 to indicate a switch housing. Within the switch housing 10, switch contacts 12 and 14 are provided, the contact 14 being carried by a switch arm 16. The switch arm 16 is pivoted to a pin 18, one end of which extends into the housing 10 and the other end of which is supported by a supporting bar 20. The supporting bar 20 is secured to the switch housing 10 by screws 22, which are shown in section, having been cut off so that most of the supporting bar 20 may be omitted to more clearly show the details of the construction.

A temperature or pressure operated bellows is indicated at 24. The bellows 24 has an operating pin 26 secured to the head 28 of the bellows. The pin 26 engages a bellows lever 30, which is pivoted to a pin 32, supported in a manner similar to the pin 18.

Movement of the bellows 24 and the bellows lever 30 is opposed by a main spring 34. The main spring 34 is suitably adjustable as to tension for causing operation of the switch contacts l2 and 14 to open and closed position at predetermined degrees of temperature or pressure within the bellows 24.

The bellows lever 30 is operatively connected with the switch arm 16 by a link or bail 36, whereby movements of the lever 30 are imparted to the arm 16.

My operation modifying means comprises generally a leaf spring 38, control shaft 40, control'knob 42 and an adjusting nut 44. The leaf spring 38 is provided with a foot 38a, per- 70 forated as indicated at 46. By means of rivets 48, extending through the perforations 46, the leaf spring 38 is connected with the bellows lever 30 for modifying the operation thereof.

The control shaft 40 is suitably joiunalled in a bearing 50 in the wall of the switch housing 10 and is held against longitudinal movement in the following described manner.

A threaded portion 52 is formed on the control rod 40 and terminates in a shoulder 54. The shoulder 54 engages a washer 56, which in turn engages one end of the bearing 50. The control knob 42 is secured to the control shaft 40 by a set screw 58. The control knob engages the other end of the bearing 50.

A friction washer is provided to prevent rotation of the control shaft 40 except when the control knob 42 is engaged and rotated by the operator.

Threadedly mounted on the screw-threaded portion 52 of the control shaft 40 is a nut 44. The nut 44 is provided with a pair of grooves 64 into which arms 66 of a forked end of the leaf spring 38 extend. Thus, as clearly shown in Figure 3, the nut 44 is held against rotation by the spring 38, but upon rotation of the control shaft 40, longitudinal movement is imparted to the nut 44 for thus swinging the leaf spring 38 and modifying the action of the bellows lever 30.

A head or collar 68 may be formed on or secured to the control shaft 40 to prevent excessive rotation of the control shaft in one direction, the washer 60 being engaged by the nut 44 when traveling in the other direction for thus limiting the rotation of the knob 42.

From the foregoing description, it is apparent that rotation of the knob 42 in one direction will tension the spring 38 to assist the bellows 24 and rotation in the opposite direction will have the reverse effect, or oppose the bellows. Thus the operation of the control structure can be modified independent of the initial adjusting spring 34.

Some changes may be made in the construction and arrangement of the parts of my device Without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents, which may be reasonably included within their scope.

I claim as my invention:

1. In a control structure, a pivoted control member and means for modifying the action thereof comprising a leaf spring attached thereto, a control shaft rotatably and nonsl idably mounted, a nut threaded thereon, said nut having a pair of oppositely disposed grooves transversely arranged relative to the axis of the control shaft, said spring having a forked end engaging in said grooves.

2. In a device of the class described, a pivoted member, a spring acting thereupon and means for adjusting the tension of said spring comprising a control shaft rotatably and nonslidably mounted, a nut threaded thereon said nut having a pair of flattened surfaces said spring having a forked end engaging said surfaces to thereby prevent rotation of said nut.

MALCOLM E. HENNING.

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