US3196707A - Switch actuating mechanism - Google Patents

Description

July 27, 1965 B. MUzzALL, JR 3,196,707

SWITCH ACTUATING MEGHANISM Filed Feb. 9, 1962 INVENTOR ,4s/f fuzz/m4, Je.

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United States Patent O 3,196,707 SWTJCH ACTUATNG h/lECl-ANlSll/l Lyle lll. Muzzall, lr., Box 56, Mount Vernon, Wash. Filed Feb. 9, 1952, Ser. No. 172,319 Claims. (Cl. 7d- 522) This invention relates to an electrical switch actuating mechanism, and more particularly to a heavy duty, weight responsive switching device with fully adjustable fulcrum means so as to be of universal application.

Switch actuating mechanism according to the invention is essentially characterized by a lever mechanism consisting of a lever arm supported on a fully adjustable fulcrum assembly and biased at one end by a spring loaded electric switch and supporting at the other end an actuating Weight.

By way of typical example, one iield of use of such a switch actuating mechanism is with respect to bulk feed receptacles such as poultry or cattle feeders, wherein one leg of the feed receptacle is placed on the outboard end of the lever arm of the mechanism. As thus installed, the level of feed in the feed receptacle is maintained by the varying weight of the receptacle shutting od and turning on the switch, which in turn controls the feed ilow to the receptacle. Regulation of the level of fill of the receptacle is by adjustment of the fulcrum means and by adjustment of the point of placement of the receptacle weight on the lever arm. Of course, the invention is not limited to the control of the bulk feed of poultry or cattle but can be used to control bulk feeding of any liquid or granular solid for any purpose. The device will thus be understood to have utilitywhereever it is desirable to have an electric switch actuated in response to change in weight.

An object of the present invention is to provide a weight responsive switching device having relatively few parts, which Iis rugged and capable of response when subjected to heavy weight, and which is also capable of being adjusted to be responsive at any desired weight over a wide range of weights.

Another object of this invention is to provide a switch of the above described character which can be manufactured solely from rolled stock material which is readily available on the open market, thus eliminating the need of any special casting or manufacturing apparatus.

A further object of this invention is to provide a switch "\of the above described character which due to its construction is able to withstand an extremely heavy loading and at the same time can be built strong enough to provide a safety factor of several times any anticipated load.

A still further object of this invention is to provide a switch of the above described character which is simple in construction, is durable in use, is efcient in operation, and can be economically manufactured.

Yet another object and commercially important feature of the invention is found in the slidably adjustable fulcrum arrangement characterizing the mechanism, enabling the mechanism to be instantly adjustable to meet the requirements of any particular use environment presented. i

More specifically, its fulcrum block or frame is simply and fully adjustable by a sliding action, even with the mechanism installed and inluse, and the wide range of adjustment thereof enables quick adaptation of the mechanism to automatically control the material flow into a receptacle such as a feed tank or trough, irrespective of whether the iilled receptacle is light or heavy. As a result of this capability, users such as farmers or industrial plants having only periodic need for such a switch actuating mechanism need have on hand only one size of mechanism. Merchandising of such mechanism is also considerably simplified in that the full flexibility of the lfi? Patented July 27, 1965 mechanism for various usages eliminates any need for an inventory of more than one size.

Other objects and advantages will be apparent from the following description, appended claims and annexed drawing.

Referring to the drawing wherein like reference characters designate like parts throughout the several views:

FIG. 1 is a perspective View of the device of this invention showing the relationship of its several parts.

FIG. 2 is a side elevation View of the invention, with various parts broken away for clarity of illustration, illustrating the mechanism in supporting relation with respect to the leg of a bulk material receptacle.

FIG. 3 is an end elevation view, taken from the inboard end of the mechanism.

FG. 4 is a sectional View taken substantially along line 4 4 of FIG. 2, and showing in detail the relationship of the lever arm to the fulcrum assembly and the base member.

Referring rst to FIG. 1 of the drawings, the mechanism of this invention comprises a housing 1t) having a base portion 12, side walls 14 and 16, and a top portion 18. The side walls 14, 15 and base portion 12 together define a generally U-shaped cross-section throughout a greater part of the length of the device, including the outboard end thereof. A top portion 18, the side walls 14, 16 and the base portion 12 together form a crosssection of box form at the inboard end of the device. An adjustable, spring loaded electric switch mechanism Ztl, of conventional type per se, is secured tothe top portion 18 and is provided with a removable cover t portion 22, a cover securing post 24, and a clamped conholes in both the plate 28 and top portion 1S, and are anchored in the base of the switch mechanism 2.9 which lies in contact with the upper surface of the top portion 1S. An access hole (not shown) is provided in the base portion of the housing beneath plate 28 for inserting the tip end of a screwdriver through when asemblying the switch and housing. Plate 28 is provided with a post 32 having a central bore through which a switch actuating member 341 projects. The Switch actuating member 34 is biased downwardly by resilient means in the form of an adjustable compression spring 36 (shown somewhat diagrammatically) located within the switch cover ZZ. ln the position shown the spring 36 normally holds switch contact points (not shown) in a closed position, thus completing a iiow control circuit of which the switch is a part. The actuating member 34 rests at its lower end against the inboard end 33 of a lever arm 4t).

The lever arm 4) is secured to the housing 19 by a locating rod 42 which extends through holes 44 drilled through the side walls 14 and 16 of the housing l@ and through the lever arm 49, being retained in position by suitable means such as cotter pins 46.

The leverjarm it? rests on a slidably adjustable fulcrum eans 43 comprising a fulcrum rod St) supported at the ends thereof by support plates 52 which cradle the rod 5t) substantially above the level of base portion 12, as best shown at FEGS. 3 and 4. The plates 52 are slidably supported by the inner surface of said base portion 12, and nest snugly between the inner surfaces of side portions 14, 16 and the outwardly facing side surfaces 4-'f lever arm 4l?. As will be apparent, the fulcrum means 4.8 is positionable anywhere longitudinally of the housing lil and lever arm itl from an inboard point where the inboard ends of plates 572 substantially contact locating rod d2, to an outboard point almost directly under the applied loading.

ln the example shown, loading is applied by a leg 5d of a tank, container or' other receptacle for the bulli material, which leg 54 can be adjustable in length in a manner conventional per se, as by having a threaded foot 5o, and is placeable at any desired point to be in contact with the upper surface of lever member dll. liengitudinal adjustment of the fulcrum means occurs, in relation to such leg Slt, simply by sliding the same along the base portion l2 and lever member dll, as indicated by the arrow designated 53 in FIG. 2. As evident, the solid line showing in FlG. 2 of the fulcrum means comprising rod 5t) and plates 52. is a typical setting thereof for actuation of the switch mechanism under a relatively light loading, while the dotted line showing of such rod and plates (as indicated at Sd and 5?!) illustrates a typicalsetting of the fulcrum means for switch actuation under relatively heavy loading.

ln consideringthe operation of the switch actuating.

mechanism illustrated, it will be understood that as illustrated in FIG. 2, the'loading exerted by leg 57i is less than necessary to overcome the reaction force of spring 36 in the switch mechanism Ztl. However, as the weight being applied to lever arm lu by leg 55E is increased, the outboard moment about fulcrum rod E@ is also increased and eventually the force of the inboard end of the lever arm itl pushing up against the actuating member overcomes theforce of the spring lo and causes actuation of the switch mechanism 2l).

When the switch mechanism 2li is used as a control for the feeding of bulk poultry or cattle feed, for example, a leg of the receiving receptacle, such as a feed tank or trough, is placed on the outboard end of the lever arm 49, as shown in FIG. 2. Bulk feed flows into the receptacle through a suitable conduit or chute from a storage chamber. In a manner conventional per se, an electrically controlled olf-on valve or gate is located in the conduit and is also included in the electric circuit with the switch mechanism 2li. in a typical circuit, the electric switch mechanism 2d is normally closed and the feed control valve or gate normally in an open position, thus allowing feed to flow from the storage chamber into the feeding receptacle. When the feed reaches the desired level in the receptacle resting on the lever arm d, the combined weight of the receptacle and bulk material it contains causes lever arm lll to pivot, which in turn causes actuation of switch mechanism Ztl, closing the bulk feed valve or gate and cutting olf the supply of feed to the receptacle. The bulk feed valve or gate then remains in its closed position until gradual removal of feed from the receptacle due to animals eating from it relieves the weight on lever arm ttl to the point where the force of spring 36 is no longer overcome. The switch mechanism 2lb is then restored to normal position, and bulk feed ilow resumes. rl`hus, a desired level of feed in the receptacle is automatically maintained by the varying weight of the receptacle shutting off and turning on the switch mechanism Ztl.

The relative lengths of the respective moment arms on each sif e of the fulcrum rod Sil determine the weight necessary to cause lever arm itl to pivot and actuate the switch mechanism Ztl. As the adjustable fulcrum assembly 4S is moved to the right (as viewed in FIG. 2),V

a greater loading is required to produce the same switch actuating force due to the unbalancing of the moment arms to the left. Conversely, a smaller weight is required when the fulcrum means is moved to the left. ln this manner the switch actuating mechanism can be adjusted to make it responsive to any loading over a wide range of receptacle weights.

alsof/o7 The holes in the side walls of the housing for locating rod l2 are slightly enlarged so as to allow for the pivotal movement of the lever arm d@ and the diagonal movement of the locating rod t2 resulting from change of position of the fulcrum means 43.

A second manner of adjustment of the actuating mechanism is by varying the point of Contact of the load (ie. leg Se) with the lever arm dll. With the fulcrum means in a set position, movement of the loading point to the left will make necessary the presence of a larger actuating weight to overcome the force of spring 36. Fine adjustment can also be achieved by varying the compression of spring 36, as by means of nut oil (FlG, 2).

Due to the unique construction of the switch actuating mechanism of this invention there is good load distribution from the point of loading to the base regardless of ethe position of fulcrum means. As best shown at FIG. 4, the actuating weight is transferred by the box construction of lever arm lll to the fulcrurn rod Sil along the full length of the latter and is then evenly divided between the plates 52. of the fulcrum means and is in turn transferred by the said plates along the length thereof to areas of the base portion l2 which are contiguous to the side portions lll 'and lo. This manner of load distribution provides for a sturdy and stable installation, even when very heavy loading is involved.

The 'box form of construction shown permits use of relatively light metals, such as aluminum alloys, so that the mechanism can be comparatively light weight and rust resistant, and is relatively inexpensive to ship in quantity.

The device is advantageously constructed wholly from rolled stock material, thus making special manufacturing equipment unnecessary. The housing in its preferred form is constructed from two pieces cut from rolled box stock. The first piece forms the base portion and a greater part of the side walls. It is cut so `as to form short side walls in that portion of the housing having a U-Shaped cross-Section and higher side walls in that portion which takes on a boX shape. The top portion and the remaining portion of the side walls of the box shaped section are cut from the second piece with the side wall portions extending downward and in abutting engagement with the upwardly extending higher side walls of the first piece. The side wall portions are welded together where they abut by conventional welding methods, and the joint is ground to form a smooth and continuous surface. The lever arm is constructed from a short length of box stock of smaller cross-section from that used in the housing. The side walls of the fulcrum are made from flat rolled stock or can be cut from scraps from the material used in the housing. The locating rod and support member portion of the fulcrum assembly are cut from small diameter rolled circular stock.

ln addition to the fabrication advantages, the use of rolled stock material results in a strong and highly durable mechanism which is able to withstand extremely heavy weights.

From the foregoing, further variations, modifications, adaptations and usages of switch actuating mechanism according to the invention will be apparent, within the scope of the following claims.

What is claimed is: y

ll. A weight responsive switch actuating mechanism comprising a base member of elongated, channeled configuration, a switch actuating member spaced above said base member, means mounting said switch actuating member on said base member, a rigid lever arm located within the channeled area of said base member with one end of said arm contacting said switch actuating member, `and fulcrum means located within the channeled area of said base member, said fulcrum means intermediately supporting said lever arm for pivotal movement thereof, said fulcrum means being slidably adjustable along the channeled area of said base member to vary the extent of lever arm loading necessary to actuate said switch actuating member. n

2. A switch actuating mechanism according to claim 1, wherein said fulcrum means laterally spans said channeled area and comprises side plates nested between said lbase member and said lever arm.

3. A weight responsive switch actuating mechanism comprising a housing having a rst portion of generally box shaped cross-section and a second portion of generally U-shaped cross-section, said housing including a base member, side walls connected to and extending upwardly from said base member, and a top plate extending between said side walls a-t the box-shaped end portion of the housing, switch means mounted on said top plate and including a spring loaded switch actuating member depending below said top plate into said box shaped end portion, a lever arm located in said extending substantially coextensively of said housing with one end thereof contacting said switch actuating member, and slidably adjustable fulcrum means located in the generally U-shaped portion of said housing and intermediately supporting said lever arm for pivotal movement so that the end thereof engaging said switch member actuates same when the other end thereof is downwardly loaded to a degree to overcome the spring loading of said switch member.

4. A switch actuating mechanism according to claim 3, wherein said lever arm includes side walls and said fulcrum means comprises laterally spaced side plates and a fulcrum rod extending between said side plates, each said plate being slidably located between a side wall of said base member and a side wall of said lever arm.

5. A switch actuating mechanism according to claim 4, wherein said side plates each include a lower supporting edge that contacts said base member so as to effectively distribute to the base member the loading exerted on said fulcrum rod by the lever arm loading.

6. A switch actuating mechanism comprising: a housing having a base portion, two side walls and a top porti-on, fulcrum means nestably supported on said base portion between the side walls thereof, a rigid lever arm nestably supported on said fulcrum means for rotation about its point of contact with said fulcrum means, said lever arm having inboard and outboard ends, an electric switch mechanism mounted on the top portion of said housing and having a switch actua-ting member in contact with the inboard end of said lever means, resilient means urging the switch actuating member to a first position, and a load bearing surface on the outboard end of said lever arm, whereby in response to the presence of a predetermined load on the outboard end of the lever arm the lever arm pivots on the fulcrum means and causes the inboard end of the lever arm to overcome the force of said resilient means and move the switch actuating means to a second position.

7. A switch actuating mechanism set forth in claim 6, wherein the fulcrum means comprises a pair of laterally spaced support plates and a fulcrum rod interconnecting between said support plates, with said `support plates cradling the fulcrum rod substantially above the level of said base portion, said support plates being supported on said base portion between the side walls, and being slidable along said base portion to adjust the lever arm moment.

8. A switch actuating mechanism as set forth in claim 7, wherein said lever arm Vis characterized by a generally box shaped cross-section with the side surfaces thereof spaced inwardly from the side walls of the housing, and wherein said fulcrum means support plates nest snugly Ibetween the inner surfaces of said housing side walls and the outwardly facing side surfaces of said lever arm.

9. A switch actuating mechanism as set forth in claim 6, wherein said resilient means comprises an adjustable compression spring.

10. A switch actuating mechanism as set forth in claim 6, wherein a locating rod extends through the side walls of the housing and through the lever arm at a point between the fulcrum means and the inboard end of the lever arm.

1l. A switch actuating mechanism as set forth in claim 10, wherein said locating rod extends through holes in the side walls of the housing which are substantially larger than said rod.

12. A switch actuating mechanism as set forth in claim 6, wherein said housing is of box form at its inboard end and channel form at its outboard end, and said lever arm is of smaller box form throughout.

13. A Weight responsive switch actuating mechanism comprising: an elongated base means; switch means including a switch actuating member spaced above said base means; resilient means normally biasing the switch actuating member toward the base means; mounting means for the switch actuating member; means mounting said mounting means onto said base means; an elongated, rigid lever arm disposed above the base means and having inboard and outboard ends, with the inboard end of said lever arm contacting said switch actuating member; and fulcrum means resting on said base means and intermediately supporting said lever arm for pivotal movement.

14. A weight responsive switch actuating mechanism comprising: an elongated base means; switch means including a switch actuating member spaced above said base means; resilient means normally biasing the switch actuating member toward the base means; mounting means for the switch actuating member; means mounting said mounting means onto said base means; an elongated, rigid lever arm disposed above the base means and having inboard and outboard ends, with the inboard end of said lever arm contacting said switch actuating member; and fulcrum means resting on said base member and intermediately supporting said lever arm for pivotal movement, said fulcrum means being slidably adjustable along the base means to Vary the extent of lever arm loading and downward displacement of the outboard end of the lever arm necessary to overcome the force of the spring means and actuate said switch actuating member.

15. A switch actuating mechanism comprising: a housing having an inboard end portion and an outboard end portion, said housing comprising a fiat, generally rectangular base, flat side walls connected to and extending upwardly from said base, said side walls being substantially higher at the inboard end of the housing than throughout the remaining portion of their extent, a relat1vely flat top plate interconnecting between :the side walls at the inboard end of the housing, switch means mounted on said top plate and including a switch actuating member depending therefrom, through an opening in said top plate, and into the inboard end of said housing, spring means normally biasing said switch actuating member toward the base member, an elongated, rigid lever arm disposed above the base and having inboard and outboard ends, with the inboard end of said lever arm contacting said switch actuating member; and fulcrum means rest- 1ng on s aid base between the side walls and intermediately supporting said lever arm for pivotal movement, a load 'bearing surface on the outboard end of said lever arm, said fulcrum means being slidably adjustable along the base to vary the amount of lever arm loading and the extent of downward displacement of the outboard end of the lever arm to overcome the force of the spring means and actuate said switch actuating member.

References Cited by the Examiner UNITED STATES PATENTS 2,119,567 6/38 Williams 74-552X 2,602,350 7/52 Marcellus 79-522 BROUGHTON G. DURHAM, Primary Examiner.

Claims (1)

1. A WEIGHT RESPONSIVE SWITCH ACTUATING MECHANISM COMPRISING A BASE MEMBER OF ELONGATED, CHANNELED CONFIGURATION A SWITCH ACTUATING MEMBER SPACED ABOVE SAID BASE MEMBER, MEANS MOUNTING SAID SWITCH ACTUATING MEMBER ON SAID BASE MEMBER, A RIGID LEVER ARM LOCATED WITHIN THE CHANNELED AREA OF SAID BASE MEMBER WITH ONE END OF SAID ARM CONTACTING SAID SWITCHING ACTUATING MEMBER, AND FULCRUM MEANS LOCATED WITHIN THE CHANNELED AREA OF SAID BASE MEMBER, SAID FULCRUM MEANS INTERMEDIATELY SUPPORTING SAID LEVER ARM FOR PIVOTAL MOVEMENT THEREOF, SAID FULCRUM MEANS BEING SLIDABLY ADJUSTABLE ALONG THE CHANNELED AREA OF SAID BASE MEMBER TO VARY THE EXTENT OF SAID LEVER ARM LOADING NECESSARY TO ACTUATE SAID SWITCH ACTUATING MEMBER.

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