US2349519A - Control device - Google Patents

Description

May 23 1.944- l w. R. RElcHENsTr-:IN 2,349,519

CONTROL DEVICE Filed Feb. v1, 1941 lg. 2 I l Jg 20 Z0 72 Z5 22 n ZZ J 4 f l 1,413 23 i 2 112i 1@ .z8 4a@ 75 5 3 l/ Il' 4 "'17 7 8 Z T 3. INVENTOR V 1g Y W//fr'edRa/phleichensein Patented May 23, 1944 UNITED STATES PATENT OFFICE CONTROL DEVICE Wilfred Ralph Reichenstein, Marion, Ohio, as-

4signor to The Fairfield Engineering Company, Marion, Ohio, a corporation of Ohio Application February 1, 1941, Serial No` 377,069

3 Claims.

in a bin containing solids `of substantial size it` may sometimes occur that due to a bridging or partial bridging of the contents of the bin against the side Wall adjacent the control device only light pressure will be exerted on the diaphragm which may be insufficient to operate the control device. I believe that the failure of control devices to operate under certain circumstances has been due to the Vfact that such devices as heretofore employed have generally had an operating member fastened directly tothe diaphragm. The

fastening of such member to the diaphragm has tended to decrease the flexibility of the diaphragm and to impair its free diaphragm action.' Moreover, when fastening means extend through the diaphragm there is always danger of damage thereto by the contents of the bin or of loosening of the fastening means or of preventing the free downward movement of the contents of the bin by reason of Contact thereof with the fastening means. Also when the diaphragm is perforated there is always danger of leakage therethrough,

particularly when verynely divided or liquid material is in contact therewith. Another disadvantage of control devices of the type in q estion such as have heretofore been employed reside in the complexity of the structure thereof. This has increased the cost of the devices and has in some cases even impaired their proper operation.

I have devised a control device which obviates the disadvantages of such devices as heretofore employed. The diaphragm is free of any permanent connection therewith of any operating member. When not compressed the diaphragm may be entirely out of contact with the operating mechanism. The structure of my control device is extremely simple and its cost much lower than comparable devices heretofore available. I provide a novel and highly effective adjustment feature without the disadvantage of employing complicated mechanisms as has heretofore been customary in the art.

l ring.

Zim-52) Other details, objects and advantages of the invention will become apparent as the following description of a present preferred embodiment thereof proceeds,

In the accompanying drawing I have shown a present preferred embodiment of the invention, in which Figure l is a plan view of a contro-l device viewed from the face thereof opposite the diaphragm;

Figure .2 is a central transverse cross-sectional view through the control device shown in Figure 1 and taken on the line II-II of that figure; and

Figure 3 is a fragmentary transverse crosssectional view taken on the line III- III of Figure 1.

Referring now more particularly to the drawing, there is shown a casing 2 which is of generally hat form as shown in Figure 2 and having a flange 3. Cooperating with the casing 2 at the bottom thereof viewing Figure 2 is a ring l1.. The casing 2 and ring 4 are preferably made of metal. The flange 3 of the casing and the ring are drilled at intervals to provide therein coaxial bolt holes 5. I provide a flexible diaphragm 6 adapted to be fastened between the casing and ring and having bolt holes adapted to register with those of the casing flange and the I also provide a sealing gasket 1. The ring has an annular groove 8 to receive the gasket 'l which lies against the outer face of the diaphragm 6 to seal the diaphragm at the outside of the control device.' The diaphragm lmay be made of any appropriate material and for many uses I prefer to make it of stainless steel. It is made of thin stock so as to be flexible and adapted upon the application of pressure to its outer face to move inwardly surnciently to operate the control mechanism presently to be described. When the casing 2 and the ring 4 are assembled with the diaphragm 6 and gasket 1 in place as shown in Figure 2, bolts 9 are introduced through some of the aligned bolt holes 5 to maintain the assembly. Preferably these assembly-maintaining bolts are passed through alternate sets of aligned bolt holes as shown in Figure 1. The bolt heads are received within countersunk openings in the ring as shown in Figure 3 so that the control device may be applied to a bin or the like at an opening therein and will lie flush against the surface thereof. When the control device is thus applied other bolts may be passed through the remaining bolt holes therein and through cooperating The diaphragm 6 is preferably applied to the I casing under tension. As above mentioned, the

diaphragm is made of thin stock and in a preferred form it is made of very thin stock such, for example, as .007" in thickness. I iind that a diaphragm made of stainless steel .007" in thickness has the requisite strength for the purpose but for best results should be applied to the casing under tension; otherwise the contact with it of the contents of the bin might impart to the diaphragm a permanent setA or bulge which would impair its operation. This is obviated by applying the diaphragm under tension. The diaphragm is preferably stretched when the ring 4 and gasket 'I are applied to the casing 2 and when this is done it will respond properly to forces acting against itat the inside of the bin to operate the control device but will not take on a permanent set or bulge, Vat least not sufficient to interfere with satisfactory operation of the control device. Thus I can use extremely thin diaphragms which are more sensitive than relatively thick diaphragms and result in more accurateoperation of the control device.

Bolted to the casing 2 at I0 is a switch mounting in the form of a bracket II. The bracket,V is preferably in the form a doubly bent exible metal strip having a connecting portion I2 through which it is bolted to the casing, a portion I3 extending substantially at right angles to the portion I2, and a resilient free arm I4 extending generally parallel to the connecting portion I2 but in the opposite direction therefrom relatively to the portion I3 of the bracket. A switch designated generally by reference numeral I5 is mounted upon the arm I4 by an angular connecting member I6. The arm I4 is resiliently movable generally toward and away from the diaphragm 6 and, since the switch I5 is carried thereby, such movement of the arm results in corresponding movement of the switch. The switch may be of any desired type, a snap action switch being shown although other types of switches may be employed. The detailed structure of the switch forms no part of the present invention and since the switch is a standard article of commerce it is not shown in detail. The particular switch illustrated is of the type known as a micro switch, a switch of this type being shown for example in United States Patent No. 1,960,020.

A switch-operating pin II is employed which is operable through the lower wall of the switch casing viewing Figure 2 and whose downward movement viewing such gure is limited so that it will not fall out of the casing. When the pin II is pushed upwardly viewing Figure 2 it operates the switch. When upward pressure on the pin is released the switch returns to its former position. Leads I8 enter the casing 2 through an outlet box I9 and are connected with the switch as shown in Figure 2. When the switch is operated by pushing the pin I'I upwardly a circuit through the leads I8 is either closed or opened depending upon the particular installation and when the pin returns to its lower position the circuit reverts to its previous condition, either open or closed as the case may be. The control device may be employed simply for operating a signal such as a bell or light or it may be employed to control meansfor filling or emptying the bin or other container. As above stated, when the diaphragm 6 is not compressed it may be entirely out of contact with the pin I'I as shown in Figure 2. The diaphragm is left free of any permanent connections which impair its resiliency and interfere with most effective operation. The pin I'I is separate from the diaphragm 6 and not permanently connected thereto but is operable by the diaphragm upon slight movement of the diaphragm due to exertion of pressure against its outer or lower face viewing Figure 2. It will be understood that the control device is generally positioned with the diaphragm extending vertically when in use although it may be used in other positions in particular installations.

I provide a very simple and effective adjusting means for the controldevice which contributes greatly to its Value. An adjusting bolt 2U is threaded through the rear wall of the casing 2 at 2|. A lock nut 22 is provided for cooperation with the outer surface of the casing. The extremity of the bolt engages the arm I4 at 23 as shown in Figure 2, such point of engagement preferably lying in the axis of the diaphragm and also lying in the axis of the pin II. By turning the bolt 20 the right-hand end of the switch-carrying arm I4 viewing Figure 2 may be moved toward or away from the diaphragm as desired. The arm is moved towardl the diaphragm by the positive downward pushing action exerted against it by the bolt and when the bolt is retracted upwardly the resilience of the arm causes it to follow the bolt at least to a certain extent. 'I'hus by a very simple and effective adjusting mechanism the switch may be adjusted toward and from the diaphragm. The movement of the arm I4 and switch I5 during the adjustment just described is angular or swinging movement since the arm I4 is part of the bracket I I which is fastened to the casing at I 0.' 'I'he structure is such, as will be appreciated, that the resilient movement of the arm partakes somewhat of the nature of swinging or pivotal movement rather than rectilinear translatory movement. This does not in any way interfere with the proper operation of the control device or the switch since the angularity of the switch even under extreme adjustment either way is Very slight. 'Ihe only portion of the switch whose proximity to the diaphragm is material is the switch-operating pin I1 and the remainder of the switch may be variously positioned so longas it does not interfere with free operation of the diaphragm.

Thus I provide a control device which is simple and inexpensive to manufacture yet which is strong and rugged, free from complicated mechanisms which are apt to get out of order, dust tight, explosionproof and readily adjustable. The diaphragm, if of stainless steel, as is preferred, is corrosion resistant. No operating mechanism is permanently connected with the diaphragm whereby to impair its resilience or y interfere with its proper operation.

While I have shown and described a present preferred embodiment of the invention, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied within the scope of the following claims.

I claim:

1. A control device comprising a casing, a diaphragm closing a face of the casing, a switch operable by the diaphragm, an adjustable mounting for the switch carried by the casing and means disposed substantially in the same line normal to the diaphragm as the switch operating portion of the diaphragm acting between the casing and the mounting for moving the mounting to desired adjusted positions whereby to adjustably position the switch relatively to the diaphragm.

2. A control device comprising a casing, a diaphragm closing a face of the casing, a switch in the casing operable by the diaphragm, a bracket fastened to the casing and having a resilient free arm, the switch being mounted on said arm, and means for resiliently moving said arm to adjustably position the switch relatively to the diaphragm.

3. A control device comprising a base member, a diaphragm mounted on the base member, a switch operable by the diaphragm, a resilient mounting member carried by the base member, the switch -being mounted on said mounting member, and means acting between the base member and the mounting member for moving the mounting member to adjustably position the switch relatively to the diaphragm to determine the sensitiveness of the control device.

WILFRED RALPH REICHENSTEIN.

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