US2855488A - Electric reversing switch - Google Patents

Description

D. F. wlLLcox Erm;

ELECTRIC REvERs'ING SWITCH 2 Sheets-Sheet l ocr. 7, 195s Filed oct. 195e 7 l /5 u I D. F. WILLCOX ETAL ELECTRIC REVERSING 'SWITCH 2 Sheets-Sheet 2 Filed Oct. 8, 1956 w IN VEN TOR5 zw/Mw v Arron/Ylfs.

Unite ELECTRIC REVERSING SWITCH Application October 8, 1956, Serial No. 614,484

4 Claims. (Cl. Zim- 168) The present invention relates generally to improvements in the art of producing electric current control apparatus, and it relates more specifically to improvements in the construction and operation of electric reversing switches of the so-called drum type.

The primary object of our invention is to provide an improved electric reversing switch which is simple in construction and eillcient in operation.

Some of the more important specic objects of the present invention are as follows:

To provide an improved reversing switch assemblage which is durable and compact in structure, and conveniently installable and manipulable.

To provide an improved drum type electric switch having a series of movable contacts oscillatable about a common axis, and the various parts of which may be readily constructed and assembled or dismantled.

To provide an improved multiple contact reversing switch unit in which the several contacts and electrical connections are normally well concealed and protected while still being quickly accessible for inspection.

To provide an improved sturdy switch mechanism having many parts formed of sheet-metal with the aid of punches and dies, and which can be produced at moderate cost.

To provide various other improvements in the construction and functioning of electric reversing switches, whereby the utility and safety thereof is enhanced.

These and other more specic objects and advantages of the invention will be apparent from the following description.

A clear conception of the several features constituting the present improvements and of the construction and operation of a typical electric reversing switch embodying the invention, may be had -by referring to the drawings accompanying and forming a part of this speciiication in which like reference characters designate the same or similar parts in the various views.

Fig. 1 is a side view of the main frame and internal mechanism of a commercial reversing electric switch in one active position, with a central vertical section through its normal closure cover, but with the actuating handle omitted;

Fig. 2 is a front elevation of the frame and internal mechanism of the switch shown in Fig. l, but having both the closure cover and the actuating handle omitted;

Fig. 3 is a front and side perspective View of the same reversing switch assemblage in inactive or neutral position, with the cover omitted but the actuating handle applied;

Fig. 4 is a top View of the same switchiassemblage with thecover and handle omitted and a corner of the top plate broken away;

Fig. 5 is a bottom View of the switch unit with the closure cover in place;

Fig. 6 is a transverse horizontal section through the reversing switch, taken along the line 6-6 of Fig. l;

Fig. 7 is. another transverse horizontal section through atent O Cce the reversing switch, taken along the line 7--7 of Fig. l; and

Fig. 8 is a top and side perspective view of the top plate of the improved switch assemblage.

While the invention has been shown and described herein as having been applied to a drum type reversing switch having three cooperating sets of fixed and movable contacts, it is not intended to restrict the use of the improved features to such an assemblage; and it is also contemplated that speciic descriptive terms employed herein be given the broadest possible interpretation consistent with the disclosure.

Referring to the drawings, the electric reversing switch shown therein comprises in a general, a unitary C-shaped main frame 10 having an upright rear wall 11 and upper and lower integral forwardly directed flanges 12, 13 respectively, of which the upper llange 12 has a central cntout 14 and opposite side notches 15, 16 and is also provided with integral depending laterally spaced front lugs 17, while the lower flange 13 is provided with a central opening 18 and with a T-shaped front notch 19 having an upstanding lug 20 therein; a top plate 21 secured to the upper frame ange 12 by screws 22, and having a central bearing bushing 23 mounted therein in axial alinement with the lower opening 18 and also having integral depending opposite side projections 24, 25 cooperable respectively with the upper tlange notches 15, 16; an upright spindle 26 journalled in the bushing 23 and the alined opening 18 and having an actuating handle 27 secured to its upper extremity, while its medial lower portion carries a series of four vertically separated disks 28 and three movable contacts 29, 30, 31 interposed between the disks 28; an upstanding ilxed contacts support 32 secured at its upper end to the upper ilange lugs 17 by screws 33 while its lower end is snugly confined within the T-notch 19 of the lower ilange 13; three pairs of stationary contacts 34, 35, 36 riveted to the support 32 and being cooperable with the movable contacts 29, 30, 31 respectively, and provided with terminal screws 37; and a closure cover 38 having U-shaped transverse cross-section and being provided with inturned upper and lower llanges 39, 40 adapted to coact with the top plate 21 and with the lower frame llange 13 respectively, and also being attachable to the lug 2t) by a screw 41.

The main C-shaped frame 10 may be formed from a single blank of relatively heavy sheet-metal with the aid of punches and dies, and the rear frame wall 11 is provided With suspension openings 43 for the switch unit, while the upper tlange 12 has a depending lug 44 near the wall 11 and the lower ilange 13 is provided with large openings 45 for introduction of the current conductors to the terminal screws 37. The top plate 21 may also be formed of durable sheet-metal and the side projection 24 is T-shaped while the opposite side projection 25 is devoid of lateral extensions as clearly shown in Fig. 8. During application of the plate 21 to the upper frame flange 12, the T-projection 24 may be hooked into the notch 15 and thereafter utilized as a pivot to swing they top plate into Contact with the ilange 12 and to cause the other projection 25 to slide into the notch 16, whereupon the bearing bushing 23 will be accurately axially alined with the lower bearing opening 18 and the screws 22 may be applied to firmly unite the trame 10 and top plate 21.

The spindle 26 which is journalled for rotation within the alined sleeve 23 and opening 1, has a large cylindrical upper end to which the handle 27 is detachably secured in any suitable manner and which is rotatable in the sleeve 23, while its lower end is also cylindrical but of smaller diameter, and its intermediate portion is square in cross-section as illustrated in Fig. 7. An indexing cam 47 is rigidly attached to the spindle 26 directly beneath the bearing sleeve 23 and this cam 47 has peripheral detents adapted to coact with a roller 48 carried by the medial portion of a sheet-metal lever 49 one end of which is swingable upon a pivot t) secured to the upper frame flange 12 while its opposite swinging end is attached to one end of a tension spring 51 the other end of which is fastened to the lug 44, as shown in Figs. 1, 3 and 6. This indexing cam 47 is adapted to position the movable contacts 29, 3f), 31 in either neutral or olf position, in forward running position, or in reverse running position when the control switch is used in a reversible motor circuit; and the lever 49 and spring 51 function to positively hold the cam 47, spindle 26, and movable contacts in either of these three positions while the handle 27 serves to set the rotary elements in the desired position.

The square medial portion of the spindle 26 is snugly embraced by a continuous square tube 53 of insulation, and the disks 28 are also formed of 'insulation and are held in spaced relation to each other by a series of collars 54, 55 likewise formed of insulation and which snugly engage the corners ofthe square tube 53, as illustrated in Fig. 7. The movable contacts 29, 30, 31 have supporting webs provided with square central openings which also snugly embrace the square tube 53, and the collars 55 are of larger external diameter than the collars 54 and engage the adjacent upright portions of the corresponding movable contacts 29, so as to improve the Contact rotating effect and to relieve the tube from excessive torque. The upper movable contact 29 has a depending long arm adapted to interconnect two of the fixed contacts 34, during one active setting of the switch, and the medial movable contact 30 has a similar upstanding long arm adapted to likewise interconnect two of the stationary contacts 34, 35 during another active setting lof the unit, but the lower movable contacts 31 are only cooperative with the lowermost fixed contacts 36.

The disks 28, movable contacts 29, 30, 31, and the collars 54, 55 may be clamped together upon the medial square portion -of the spindle 26 by means of a clamping nut 56 as depicted in Figs. 1 and 3, thus providing a positive driving connecti-on lbetween this spindle and the movable contacts while also insulating the latter from each other. The stationary contacts 34, 35, 36 are resiliently supported by leaf springs 57 attached to the front contact support 32, and this support 32 is formed of durable insulation and is detachably secured to the main frame flanges 12, 13 by the lower T-notch 19 and by the screws 33 coacting with the frame lugs 17, as well as by the screw 41 when the cover 38 is in place. The upright support 32 is of considerable width and cooperates with the peripheries of the insulation disks 28 to segregate the several contact confining spaces, and the U-shaped closure cover 38 may also be formed of sheet metal with the aid of punches and dies and lined with a sheet of asbestos sheeting as usual, and the flanges 39, 40 of this cover may be slid along the opposite sides of the parallel upper and lower flanges 12, 13 to either totally enclose the switch contacts or to expose them on three sides when the cover 38 is withdrawn. The crank handle 27 may be formed of brilliantly colored plastic and preferably points forwardly when the switch is open, and may be swung to either side to produce forward and reverse setting.

The improved switch hereinabove described is primarily a reversing switch adapted to control reversible electrical equipment such as an electric motor, and when the various parts have been properly constructed and assembled as described, the unit may be readily installed in an electrical control system by removing the cover 38 and connecting the proper conductors to the fixed contacts 34, 35, 36 with the aid of the terminal screws 37. The cover 38 may then be slipped in place and secured to the frame lug 20 with the aid `of the screw 41, after which the handle 27 may be manipulated to position the movable contacts 29, 30, 31 in either ot position, forward running position, or reverse running position in an obvious manner. The indexing cam 47 in cooperation with the lever 49 and spring 51 will always positively maintain the handle 27, spindle 26 and the movable contacts in the several selected positions, and this spring 51 also functions to move the contacts 29, 30, 31 from one position into another with a decided snap and contact wiping action. The support 32, disks 28, tube 53, and collars 54, 55 all being formed of insulating material effectively prevent possible short-circuiting, and the cover 38 while normally concealing and protecting the internal switch element may be quickly removed to provide unobstructed access to these elements.

The main frame 10, top plate 21, cover 38, and lever 49 may all be conveniently and accurately formed of sturdy sheet metal, and may also be readily assembled or dismantled by merely manipulating a few screws. By removing the handle 27 and the screws 22 and releasing the spring 51 from the lug 44, the top plate 21 may be easily withdrawn. Upon removing the screws 33 from the frame lugs 17 and by thereafter swinging the support 32 forwardly and releasing its lower end from the T-shaped frame notch 19, this support 32 together with the fixed contacts 34, 35, 36 may also be freely removed. After the t-op plate 21 and the support 32 have been thus removed, the'spindle 26 together with the movable contacts 29, 30, 31 and the cam 47 may also be easily withdrawn forwardly through the forwardly open cut-out 14 in the upper frame flange 12. Assembly or reassembly of the improved switch unit may be just as conveniently and quickly effected by reversing the foregoing dismantling operations, and the entire structure is extremely compact and durable when assembled.

From the foregoing detailed description it will be apparent that the present invention in fact provides an improved electric switch unit especially of the reversing drum type, which can be easily installed and operated with utmost safety. All parts of the improved assemblage can be readily produced with utmost precision and at moderate cost, and the more delicate elements are well concealed and protected during normal use of the switch while still being conveniently accessible for inspection. The various parts of the improved switch are very durable in structure thus insuring long life, and the improved reversing switch has proven highly satisfactory and successful in actual commercial use.

It should be understood that it is not desired to limit this invention to the exact details of construction and operation of the drum type controller herein specifically shown and described, for various modifications within the scope of the appended claims may occur to persons skilled in the art.

We claim:

1. In an electric switch, a C-shaped sheet metal frame having a wall provided with integral flanges projecting from its opposite ends, one of said flanges having a slot and an adjoining lug near its free end and the other having a cut-out extending inwardly from its free end and a lug on each side of said cut-out, a fixed contact support having one end confined within said slot and secured to said adjoining lug and having its opposite end secured to said side lugs, a spindle journalled in said slotted flange and projecting freely through said cut-out of the other flange, a bearing plate for said spindle having opposite side projections interlockable with the opposite sides of said other flange, movable switch contacts carried by said spindle, stationary switch contacts carried by said support and being cooperable with said movable contacts, and a reversely C-shaped sheet metal cover having a wall provided with integral flanges projecting from its opposite ends and overlapping said frame flanges and said interlockable projections, said cover being detachably secured to the frame by a single fastener coacting with said slot adjoining lug.

2. In an electric switch, a f3-shaped sheet metal frame having a wall provided with integral anges at its opposite ends, one of said langes having a central lug near its free outer end and the other flange having a central cut-out extending inwardly from its free outer end and a lug on each side of the cut-out, a fixed contact support having its opposite ends secured to said lugs, a spindle journalled directly in said centrally lugged flange and projecting freely through said cut-out of the other flange, a bearing plate for said spindle secured to said other llange and spanning the cut-out, movable switch contacts carried by said spindle between said anges, and stationary switch contacts carried by said support and being cooperable with said movable contacts, said spindle being removable from said frame through said cut-out upon release of said support from said lugs.

3. In an electric switch, a frame having a wall and integral flanges projecting in the same direction from the opposite ends of said wall, one of said flanges having an integral central lug near its end remote from said Wall and the other ange having a central cut-out extending inwardly toward said wall and being provided with a pair of spaced lugs on opposite sides of the cutout, a iixed contact support having its opposite ends attached to said lugs to provide a three point mounting for the support, a spindle journalled at one end directly in said centrally lugged flange while its opposite end portion extends freely through said cut-out of the other tlange, a bearing plate for said opposite spindle end portion secured to said other flange and spanning said cut-out, movable switch contacts mounted on said spindle between said anges, and stationary switch contacts mounted on said support and being cooperable with said movable c011- tacts, said spindle being removable from said frame through said cutout upon release of said support from said lugs.

4. In an electric switch, a frame having a wall and integral anges projecting in the same direction from the opposite ends of said wall, one of said langes having an integral central lug near its end remote from said wall and the other flange having a central cut-out extending inwardly toward said wall and being provided with a pair of spaced lugs on opposite sides of the cut-out, a xed contact support having its opposite ends attached to said lugs to provide a three point mounting for the support, a spindle journalled at one end directly in said centrally lugged flange while its opposite end portion extends freely through said cut-out of the other lange, a bearing plate for said opposite spindle end portion having projections interlockable with the opposite sides of said other ange and spanning said cut-out, movable switch contacts mounted on said spindle between said flanges, stationary switch contacts mounted on said support and being cooperable with said movable contacts, and a closure cover for said contacts having a wall integral side flanges overlapping the edges of said frame flanges and said projections and being detachably secured only to said central lug.

References litcd in the nie of this patent UNlTED STATES PATENT S 1,169,957 Henry Feb. 1, 1916 2,113,463 Hall Apr. 5, 1938 2,680,794 Ballou June 8, 1954 FOREGN PATENTS 658,659 Germany Apr. 1l, 1938 934,100 France Jan. 7, 1948

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