Safety interlock switching device for protecting equipment

Abstract

A safety interlock switching device for protecting equipment, which assures the switching-off of the dangerous operating condition in the opened position of the protecting equipment, and comprises a housing, a toggle lever provided with a pivotably mounted locking lever which has two dead center points and has a cam surface which cooperates with a respective cam surface of an actuating element rigidly mounted on the protective hood and insertable into the housing. A switch is provided which actuates the toggle lever. The toggle lever and the switch are positioned in the housing of the switching device. The housing has an insertion opening into which the actuating element is insertable. In one dead center position of the toggle lever, the locking lever and the actuating element interlock with each other, and in the other dead center position the dangerous operating condition is switched off by the switch, and the actuating element with the protective hood are released.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims: 
     
       1. Safety .[.interlock switching device.]. .Iadd.lock .Iaddend. for .[.protecting.]..Iadd.preventing access to hazardous .Iaddend.equipment, in particular .[.in.]. current conducting equipment, .[.wherein.]. .Iadd.provided with .Iaddend.a .[.given protection.]. .Iadd.protective .Iaddend.device .[.(5),.]. normally closed during .[.dangerous operation.]. .Iadd.a hazardous operating .Iaddend.condition and opened during .[.non-dangerous.]. .Iadd.a non-hazardous .Iaddend.operating condition, .[.the switching device.]. .Iadd.said lock .Iaddend..Iadd.comprising: .Iaddend.a housing.[.,.]. .Iadd.adapted to be mounted on said equipment and provided with an insertion opening; .Iaddend.a toggle lever .[.(14,15) provided.]. .Iadd.including first and second elongate members pivotably connected to each other and cooperating .Iaddend.with a pivotable locking lever .[.(8).]., .Iadd.said elongate members being pivotably connected to said housing and to said locking lever, respectively, for movement .Iaddend..[.pivotable.]. between .[.two.]. .Iadd.first and second .Iaddend.dead center positions .Iadd.,said locking lever being provided with first locking means and being pivotably mounted on said housing in a position accessible through said insertion opening.Iaddend.; an actuating element .[.(9) stationarily.]. .Iadd.provided with second locking means and adapted to be .Iaddend.mounted on said .[.protection.]. .Iadd.protective .Iaddend.device, .Iadd.for movement therewith into and out of said insertion opening to cooperate with .Iaddend.said locking lever.Iadd.; .Iaddend.cooperating with said actuating element,.]. switch means .[.connected to and.]. cooperating with .Iadd.and responsive to the movement of .Iaddend.said toggle lever.[.,.]..Iadd.;said first and second locking means .Iaddend..[.said actuating element and said locking lever being provided with locking means.]. cooperating with each other so that in .[.one.]. .Iadd.said first .Iaddend.dead center position .[.of the toggle lever (14,15) the locking lever (8) and the actuating element (9).]. .Iadd.they .Iaddend.interlock .[.with each other.]. and .[.the.]. .Iadd.said hazardous.Iaddend..[.dangerous.]. operating condition may be switched on by said switch means and in the .[.other.]. .Iadd.second .Iaddend.dead center position .[.the dangerous.]..Iadd.they are released and said hazardous .Iaddend.operating condition is switched off by said switch means .[.thus releasing the actuating element (9) and the protection device (5) therewith, said toggle lever and said switch means being disposed in said housing which is closed and is not accessible from the outside, said housing being provided with an insertion opening for inserting the actuating element (9) into said housing.].. 
     
     
       2. .Iadd.The lock .Iaddend..[.Device.]. in accordance with claim 1, wherein .Iadd.said first and second locking means comprises alternating complementary trapezoidal protrusions in said .Iaddend..[.the.]. locking lever .[.(8).]. and .[.the.]. .Iadd.said .Iaddend.actuating element .[.(9) are alternately provided with trapezoidal protrusions (8a,8b; 9b,9c) and recesses (8c;9d) which consitute said locking means and said prot and recesses intermeshing.]. .Iadd.adapted to mesh .Iaddend.with each other when .[.the.]. .Iadd.said .Iaddend.actuating element .[.(9).]. is inserted in said housing .[.so that the.]. .Iadd.through said insertion opening.Iaddend., .Iadd.whereby said .Iaddend.toggle lever .[.(14,15).]. is .[.brought.]. .Iadd.moved .Iaddend.into .[.the one.]. .Iadd.said first .Iaddend.dead center position corresponding to the .[.dangerous.]. .Iadd.hazardous .Iaddend.operating condition and interlocks .[.the.]. .Iadd.with said .Iaddend.locking lever .[.(8).].. 
     
     
       3. .[.Device.]. .Iadd.The lock .Iaddend.in accordance with claim 2, wherein .[.the.]. .Iadd.said elongate members .Iaddend..[.of said toggle lever consists of two levers (14,15) which.]. are .Iadd.at one of their ends .Iaddend.connected with each other by a center joint.Iadd., .Iaddend..[.(14a), one (14) of said levers facing away.]. .Iadd.the elongate member remote .Iaddend.from .[.the.]. .Iadd.said .Iaddend.locking lever .[.(8).]. being .[.held on.]. .Iadd.at its other end connected to said housing by .Iaddend.a .Iadd.first .Iaddend.stationary pivot bearing .[.(17) at its one end, the other .[.(15) of said levers.]. .Iadd.elongate member .Iaddend.having .[.one.]. .Iadd.its other .Iaddend.end connected with .[.the.]. .Iadd.said .Iaddend.locking lever .[. (8).]. by a joint .[.(15a).]., .Iadd.the end of .Iaddend.said locking lever .[.(8) being held at an end thereof which faces away.]. .Iadd.remote .Iaddend.from .[.the.]. said other .[.of said levers,.]. .Iadd.elongate member being pivotably connected to said housing by .Iaddend. .[.on.]. a .Iadd.second .Iaddend.stationary pivot bearing (16). 
     
     
       4. .[.Device.]..Iadd.The lock .Iaddend.in accordance with claim 3, further .[.including.]. .Iadd.comprising .Iaddend.a pull lever .[.(19).]. .Iadd.having one end .Iaddend.pivotably .[.mounted on the.]. .Iadd.connected to said .Iaddend.center joint .[.(14a), a holding magnet (18).]. .Iadd.and an electromagnet .Iaddend.having an anchor .[.(18a),.]. .Iadd.connected .Iaddend.to .Iadd.another end of .Iaddend.said pull lever .[.being connected with the anchor (18a) of the holding magnet (18) by a joint (18b).].. 
     
     
       5. .[.Device.]. .Iadd.The lock .Iaddend.in accordance with claim 4, wherein said switch means .[.include an.]. .Iadd.comprises a first .Iaddend.electrical switch .[.(20).]. having a plunger .[.(20a).]. .Iadd.engageable with an extension of said one elongate member extending beyond said first stationary pivot bearing .Iaddend.and a second electrical switch .[.(22).].having a plunger .[.(22a), and.]. .Iadd.cooperating with .Iaddend.a pivotable switch lever .[.(21) held in.]. mounted on a pivot bearing .[.(21b), said one lever (14) being provided with an extension part (14b) extending beyond the pivot bearing (17) and engaging the plunger (20a) of the electrical switch (20),.]. .Iadd.and by an outer end engaging an extension of said .Iaddend. .[.the.]. locking lever .[.(8) being provided with an extension part (8d).]. extending beyond .[.the.]. said second stationary pivot bearing .[.(16) and engaging on an outer end (21a) of the switch lever (21), said switch lever (21) cooperating with the plunger (22a) of the electrical switch (22).]., so that in .[.the one.]. said second dead center position .[.of the toggle lever (14,15) the.]. said first and second electrical switches .[.(20,22).]. are opened.[., an.]. to interrupt operating current .[.is interrupted and the holing magnet (18) has no current.]..Iadd.in the electromagnet,.Iaddend.while in the .[.other.]. first dead center position in which the locking lever .[.(8).]. and the actuating element .[.(9).]. interlock .[.with each other, the holding magnet (18) is.]. .Iadd.said first and second switches are .Iaddend.switched on .Iadd.to energize said electromagnet with current to hold .Iaddend. .[.and holds the.]. said toggle lever .[.(14,15).]. in .[.the other.]..Iadd.said first .Iaddend.dead center position.[., and the switches (20,22) are switched on for an operating current.].. 
     
     
       6. .[.Device.]. The lock in accordance with claim 5, wherein a joint bolt .[.(24).].is provided , which is positioned .[.in.]. .[.the.]. said center joint .[.(14), said levers (14,15) of the toggle lever and the.]. for pivotably holding said pull lever .[.(19) being held.]. and said elongate members together .[.with said bolt in a pivotal movement toward each other.]., .[.the.]. .Iadd.and wherein said second stationary .Iaddend.pivot bearing .[.(16) of the locking lever (8) being.]. is provided with a position bolt .[.(25).]. mounted on an inner wall .[.(26).].of .[.the.]. .Iadd.said .Iaddend.housing .[.(7), and the.]. .Iadd.said .Iaddend.locking lever .[.(8).].and .[.the one lever (15) of the toggle lever.]. .Iadd.said other elongate member .Iaddend.being pivotably connected .[.with each other.]. by a .Iadd.further .Iaddend.joint bolt .[.(27).].. 
     
     
       7. .[.Device.]. The lock in accordance with claim 6, wherein .[.the.]. .Iadd.said further .Iaddend.joint bolt (27) is .[.extended.]. .Iadd.extending .Iaddend.toward .[.the.]. said inner wall .[.(26) of the housing (7) and has.]. and is provided with an axial bore.[.,.]. .Iadd.for supporting a pressure spring .[.(29) being supported in said axial bore, and said joint bolt further.]. including a locking ball .[.(28).]., said .[.housing having.]. inner wall being provided with a .[.locking.]. recess member .[.30 cooperating with.]. .Iadd.for releasably retaining .Iaddend.said locking ball .[.in accordance with the.]. .Iadd.when said toggle lever is in said second .Iaddend.dead center position .[.corresponding to the non-dangerous operating condition.]. , said .Iadd.further joint .Iaddend.bolt (27) further supporting on a circumference thereof a shank spring .[.(23).]. having one shank end .[.(31) which is.]. positioned on .[.the.]. .Iadd.said .Iaddend.position bolt .[.(25).]. and .[.the other.]. .Iadd.another .Iaddend.shank end .[.(32) which engages on the lever (15).]. .Iadd.engaging said second elongate member. .Iaddend. 
     
     
       8. .[.Device.]. .Iadd.The lock .Iaddend.in accordance with claim 7, wherein .[.the.]. .Iadd.said .Iaddend.housing .[.(7).]. is separated into two discrete chambers .[.(33,39).]., one of said chambers .[.(39).]. receiving said electromagnet and being .[.defined to receive.]. .Iadd.sealed .Iaddend. .[.said holding magnet (18) said one chamber being sealed from the outside.]., .[.a shaft (34) being supported in.]. the other.[.(33) of said chambers.]. .[., the.]. .Iadd.being provided with said insertion opening and housing said .Iaddend.locking lever .[.(8) being.]. mounted on .[.said shaft (34), said.]. .Iadd.a .Iaddend.shaft extending .[.into the sealed chamber (39).]. .Iadd.between said two chambers .Iaddend.via a .Iadd.sealed .Iaddend.bearing bushing .[.(36) and being sealed in said bushing by a sealing .[.(37,38).]., and cooperating with .[.a lever (35) which transmits the pivot.]. .Iadd.said other elongate member for transmitting the pivotal .Iaddend.movement of .[.the.]. said locking lever .[.(8).].to .[.the.]. .Iadd.said .Iaddend.toggle lever .[., the other chamber (33) being provided with the insertion opening for the actuating element (9).].. 
     
     
       9. .[.Device.]. .Iadd.The lock in accordance with claim 1, wherein .[.the.]. .Iadd.said actuating element .[.(9).]. is connected .[.with the protection.]. .Iadd.to said protective .Iaddend.device .[.(5).]. by a flange .[.(11) having.]. .Iadd.provided with .Iaddend.a recess .[., and.]. .Iadd.containing .Iaddend.a packing .[.(12) is provided in the recess of this flange.].. 
     
     
       10. .[.Device.]. .Iadd.The lock .Iaddend.in accordance with claim 9, wherein a flange .[.(41).]. .Iadd.formed of a sheet metal and having a serrated opening .Iaddend. .[.(41a),.]. is rigidly mounted on the insertion opening of said housing .[.(7), said flange being and.]., said actuating element .[.(9).]. having a cross-section corresponding to said .Iadd.serrated .Iaddend.opening. 
     
     
       11. .[.Device.]. .Iadd.The lock .Iaddend.in accordance with claim 1, wherein said insertion opening .[.has a wipe of.]. .Iadd.is provided with a wiper .Iaddend.packing .[.(10) inserted in a wall of said housing.]. .Iadd.for cleaning said actuating element. .Iaddend. .Iadd.12. Apparatus for controlling the operating condition of hazardous equipment having first and second protective cover means mounted for movement relative to each other between open and closed positions and for selectively interlocking said first and second cover means in said closed position, said apparatus comprising: an actuating bolt provided with locking means and mounted on said first cover means to extend behind said second cover means when in said closed position;   a housing mounted on said second cover means and provided with an insertion opening;   means mounted in said housing and accessible through said insertion opening for cooperating with said locking means, comprising elongate latch means mounted at one of its ends for pivotable movement between a first position in which it engages said locking means of said actuating bolt thereby interlocking said first and second cover means, and a second position out of engagement with said locking means to allow movement of said first and second cover means to their open position;   toggle lever means comprising first and second link means joined at one of their ends for movement between first and second dead center positions, said first link means being pivotably mounted at its other end to said housing and said second link means having its other end pivotably connected to the other end of said latch means;   electromagnetic means comprising means movable between first and second positions and joined to said links at their one end;   switch means responsive to movement of said toggle lever means between its first and second dead center positions for respectively energizing and deenergizing said electromagnetic means and said hazardous equipment. .Iaddend. .Iadd.13. The apparatus of claim 12, wherein said locking means comprises a recess of trapezoidal configuration and extending radially into said actuating bolt and said latch means is provided with a protrusion complementing said recess. .Iaddend. .Iadd.14. The apparatus of claim 12, further including wall means for dividing said housing into two discrete chambers, said electromagnetic means, said switch means, and said toggle lever means being provided in one of said chambers, said other end of said second link means being connected to a shaft journalled in said wall means. .Iaddend. .Iadd.15. The apparatus of claim 14, wherein said insertion opening and said latch means is provided in the other of said chambers and connected to said other end of said second link means by said shaft journalled in said wall. .Iaddend. .Iadd.16. The apparatus of claim 12, wherein said insertion opening is formed of a flange made of sheet metal and is of serrated configuration and said actuating bolt has a cross-section complementary to said serrated configuration. .Iaddend. .Iadd.17. The apparatus of claim 16, wherein said insertion opening is provided with a wiping packing. .Iaddend. .Iadd.18. The apparatus of claim 12, wherein said electromagnetic means comprises anchor means provided with a pull lever connected to said toggle lever by said one ends of said first and second link means. .Iaddend. .Iadd.19. The apparatus of claim 12, wherein said switch means is adapted to energize said electromagnetic means and said hazardous equipment when said latch means is in its first position. .Iaddend.