|Publication number||US3632914 A|
|Publication date||Jan 4, 1972|
|Filing date||Dec 28, 1970|
|Priority date||Dec 28, 1970|
|Also published as||CA936206A1, DE2162079A1, DE2162079B2, DE2162079C3, DE7147102U|
|Publication number||US 3632914 A, US 3632914A, US-A-3632914, US3632914 A, US3632914A|
|Inventors||Osika Thomas F|
|Original Assignee||Mc Gill Mfg Co|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (2), Referenced by (11), Classifications (6)|
|External Links: USPTO, USPTO Assignment, Espacenet|
United States Patent 6 Claims, 5 Drawing Figs.
US. Cl 200/42 T, 70/203 Int. Cl 1101b 27/00 Field of Search. 200/42, 42 T; 70/203  References Cited FOREIGN PATENTS 1,106,391 5/1961 Germany 200/42 T 1,076,787 3/1960 Germany 200/42 T Primary Examiner-Herman J. Hohauser Attorney-Mueller & Aichele ABSTRACT: A key-operated electrical switch includes a rocker member which is rotatably mounted about an axle connected between two trunnions on the top of the switch easing. A carrier member is likewise mounted about the axle and has a portion which extends into the switch casing to operate the bridge mechanism for opening and closing the switch contacts. The rocker and the carrier member are free to rotate relative to one another about the axle with the carrier member moving into a cavity in the rocker. The lcey is inserted into the rocker and carrier to connect them together such that movement of the rocker will move the carrier in unison therewith to operate the switch.
PATENTEUJAW m EJ632314 INVENTOR 'THOMAS EOSIKA ATTORNEYS.
KEY-OPERATED ELECTRICAL SWITCH BACKGROUND OF THE INVENTION Although key operated electrical switches are known in the art they generally are of the type wherein the key actually extends into the switch casing and provides the actuator for operating a bridge device to open or close the switch contacts. These types of switches require unique designs which are costly to manufacture. Furthermore, in switches of this design the switch may not be turned on or off without the presence of the key.
SUMMARY OF THE INVENTION It is an object of this invention to provide an economical key-operated electrical switch.
It is another object of this invention to provide a keyoperated electrical switch which may be operated even with the key removed to deenergize the switch with the same being in the on position.
In one particular embodiment of this invention a keyoperated electrical switch includes a switch housing which encloses contacts and a bridge member. A carrier member for operating the bridge member to selectively open and close the contacts is rotatably mounted to a pin member or axle which extends between first and second trunnions connected to the top of the switch housing. A rocker member has an integral portion which is also rotatingly mounted about the axle and extends into the carrier member. In this manner the carrier member and the rocker member are movable relative to one another with the carrier member moving into a hollow portion in the body of the rocker member. A key is removably positioned to extend through the rocker member and into the carrier member. It acts to connect the two so they move in unison and not relative to one another with operation of the rocker to selectively open and close the contacts. With the key removed from the members, the rocker moves relative to the carrier to render the switch inoperative.
In some embodiments it is desirable to have a restricted portion in one end of the hollow opening of the rocker body into which the carrier member rotates. In this embodiment with the rocker positioning the carrier member to close the switch contacts and with the key removed, movement of the rocker member in a direction to open the switch contacts will cause the carrier member to engage the rocker in an interference fit with the restricted portion of the opening in the rocker member, so continued movement of the rocker moves the carrier to open the switch contacts even though the key has been removed. With the contacts open and the key removed any at tempt to move the rocker member to close the contacts will cause the rocker to move relative to the carrier member with the carrier moving into the unrestricted opposite end of the hollow portion of the body of the rocker thereby rendering the switch inoperative.
DESCRIPTION OF THE DRAWING FIG. 1 is a side elevation view partially in cross section of the key operated switch in accordance with this invention;
FIG. 2 is a side elevation view partially in cross section of the switch of FIG. 1 illustrating a different operating position thereof;
FIG. 3 is a side elevation view partially in cross section of the switch of F IG. 1 showing the key removed;
FIG. 4 is a top elevation view of the switch of FIG. 3; and
FIG. 5 is a side elevation view partially in cross section of a further embodiment of the switch of FIG. 1 in accordance with this invention.
DETAILED DESCRIPTION Referring to FIG. 1 there is shown a switch casing con taining a switch mechanism therein which includes contacts 12 and 14, which are electrically connected to terminals 16 and 18. A bridge member 20 has a contact portion 22 on the end thereof which mates with the contact surface 12 to complete the circuit between the terminals 16 and 18 through contacts 14 and 12 and the bridge member 20. A pair of supports or trunnions 24 and 26 (FIG. 4) are connected to the switch casing 10 in a spaced relation to one another. A pin member 28 extends between the trunnions 24 and 26 and acts as an axle for pivotingly and rotatingly mounting a carrier member 30 between the trunnions. The carrier member 30 has a portion 32 which extends downwardly into the switch casing. A plunger 34 is resiliently mounted (not shown) within the portion 32 in the known manner. A boss portion 36 on the contact 14 provides for detent operation of the bridge member 20.
With the carrier member 30 moved to a first predetermined position, the plunger 34 as viewed in FIG. I is on the left hand side of contact 14 and its support 17 and resiliently biases the bridge member and the contact portion 22 to make an electrical connection with the contact 12 of terminal 16 thereby completing the circuit. As shown in FIG. 2 with the carrier member 30 positioned to its second predetermined position, the plunger 34 has now been moved to the right hand side of the contact 14 thereby resiliently biasing the bridge member 20 to break the electrical connection between the contacts 22 and 12. The end of the bridge member 20 opposite the contact portion 22 rests on an insulated step portion 40 within the switch casing with the switch in an off position.
A rocker member 45 is provided as the switch operator. The rocker 45 has a hollow cavity or portion 47, a leg member 50 is integrally molded between the walls of the rocker 45, and extends outwardly of the hollow portion 47 downwardly into a cavity in the carrier member 30. This leg portion 50 is also rotatingly and pivotally mounted about the axle 28 in the same fashion as the carrier 30. Therefore, the rocker 45 and the carrier 30 may be rotated relative to one another about the axle 28 with the carrier member rotating within the hollow cavity 47 of the rocker 45.
A key member is provided to connect the rocker 45 and the carrier 30 together such that they will rotate in unison about the axle 28 to selectively bridge the contacts 12 and 14 to render the switch on" and to open the contacts 12 and 14 to render the switch off." The key 60 is positioned through an aperture 62 (FIG. 4) in rocker 45 and extends downwardly into a keyway 64 which is positioned immediately adjacent the leg 50 of the rocker 45. As can be seen in FIG. 2, the key is shaped to fit the curvature of the rocker and includes a leg 65 which extends into the keyway and wedges against the leg 50 of the rocker 45. This firmly connects the rocker to the carrier permitting the two pieces to move in unison to operate the switch.
This switch, therefore, operates like any rocker switch with the key in position. However, it provides an excellent safety feature for instance with power tools and the like where the operator by removing the key is able to render the switch inoperative until the key is replaced.
A further safety feature can be provided in this switch. If the switch is in the on" position as shown in FIG. 1, and for some reason the key 60 is removed, the operator can still turn the switch off in case of an emergency. To provide this a projection is formed within the cavity 47 of the rocker 45 simply by extending the thickness of the walls of the cavity at the end 72 of the rocker 45 thereby restricting the opening therein. As shown in FIG. 1, with the carrier member in the first predetermined or on" position should the key 60 be removed, movement of the rocker 45 relative to the carrier 30 toward the second predetermined or off position will cause the wall 70 forming the cavity 47 to interfere with the stop member 78 extending from the carrier 30 such that continued movement of the rocker will operate the carrier to open the bridge and break the contacts. However, with the: key removed and the switch turned off in this manner, as can; be seen in FIG. 3, any attempt to move the rocker 45 in a manner to close the switch contacts simply causes the rocker 45 to move relative to the carrier member 30 with the cavity 47 of the rocker 45 rotating about the carrier 30.
It should be noted that the member 78 not only provides an interference fit with the cavity wall 70 in the manner heretofore described, but it also serves as a stop (FIG. 3) to set the first predetermined or on" position of the carrier 30 against the spring pressure of the plunger 34. Likewise, the member 82 serves as a stop to set the second predetermined or off" position of the carrier 30. With the key 60 removed from the rocker 45 and the carrier, the beak portion 80 or the rocker 45 provides the stop action against extreme rotation of the rocker 45 about the carrier 30.
In the switch embodiment shown in FIG. 5, corresponding parts of the switch as shown in FIG. 1 are given like numbers. In this embodiment, the principal difference is that the rocker 90 takes on a different shape than the rocker 45 of the switch shown in FIG. 1. Furthermore, the key 95, rather than having one leg 65 as does the key 60 of the switch of FIG. 1, has two legs 96 and 97. These legs fit into two keyways provided on either side of the leg 50 which is connected to the rocker 90. It should also be noted that raised portions 100 and 101 are located on legs 96 and 97 of the key 95 and are matched with corresponding ledges 102 and 103 of the rocker 90 such that they provide a detent action when the key is properly inserted into the switch when joining the rocker 90 and the carrier member 30.
What has been described, therefore, is a simple and economical key operated switch which may be operated to render the switch inoperative with the same having been placed in the on position and the key being removed therefrom.
1. A key-operated electrical switch including in combination, a switch housing enclosing a switch mechanism therein, first moveable means coupled to said switch housing for operating said switch mechanism, rocker means coupled to said switch housing and moveable by the switch operator relative to said first means, and a key member for selectively connecting said first means and said rocker means, said key member extending through said rocker means and into said first means thereby connecting said first means and said rocker means so movement of said rocker means moves said first means and said key member in unison therewith to operate the switch, with said key member being removed from said first means and said rocker means said rocker means moves relative to said first means thereby rendering the switch inoperable 2. The key operated electrical switch of claim 1 further including second means mechanically cooperating with one of said first means and said rocker means, said second means for connecting said first means and said rocker means only with the switch in the on" position and with said key member being removed thereby disconnecting said first means and said rocker means so movement of said rocker means moves said first means in unison therewith to turn the switch off.
3. A key-operated electrical switch including in combination, a switch housing enclosing contact means and a bridge member, a carrier member for operating said bridge member for selectively opening and closing said contact means, first and second support means connected to said switch housing in a spaced relation to one another, a pin member extending between said support means, said carrier member being rotatingly mounted to said pin member between said support means, said carrier member moveable between a first or on position and a second or off position for operating said contact means, a rocker member having a body with a hollow portion therein and a leg member integral with said body and extending outwardly of the hollow portion, said leg member extending into said carrier member and being rotatingly mounted to said pin member, said carrier member and said rocker member being moveable relative to one another about said pin member with the hollow portion of said rocker member rotating about said carrier member, and key means removably positioned to extend through said rocker member and into said carrier member, said key means in said position connecting said rocker member to said carrier member so the same move in unison with said key means and not relative to one another to selectively open and close said contact means, and said key means being removed from said position, said rocker member moves relative to said carrier member rendering the switch inoperative.
4. The key-operated electrical switch of claim 3 wherein said key means includes detent means for informing the switch operator when said key means is positioned to connect said rocker member to said carrier member.
5. The key-operated electrical switch of claim 3 further including means integral with one of said carrier member and said rocker member for connecting said members so the same move in unison with said key means being removed from said position, said means acting to connect said members only with said rocker member and carrier member positioned to close said contact means thereby permitting said rocker member to be moved to open said contact means being removed from the switch.
6. The key-operated electrical switch of claim 5 wherein said means includes a portion of the body of said rocker member extending into and restricting a portion of the opening of said hollow portion thereof, whereby with said rocker member and said carrier member being positioned to close said contact means and said key means being removed therefrom, said extended body portion of said rocker portion interferes with and prohibits the hollow portion of said rocker member from rotating about said carrier member with said rocker member being rotated about said pin member so said members move in unison to open said contact means, and with said carrier member positioned to open said contacts further movement of said rocker member about said pin member to close said contacts moves the same relative to said carrier member with the hollow portion of said rocker member rotating about said carrier member to render the switch inoperative.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|*||DE1076787A||Title not available|
|DE1106391B *||Sep 26, 1959||May 10, 1961||Berker Geb||Verschliessbarer elektrischer Wippenschalter|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3906176 *||Aug 2, 1974||Sep 16, 1975||Hubbell Inc Harvey||Tamperproof switch|
|US4230917 *||Feb 12, 1979||Oct 28, 1980||Mcgill Manufacturing Company, Inc.||Removable-key rocker type switch for two circuits|
|US4359615 *||Aug 14, 1981||Nov 16, 1982||Black & Decker Inc.||Switch and means to prevent unauthorized operation thereof|
|US4767895 *||Oct 27, 1987||Aug 30, 1988||Eaton Corporation||Removable key off-lock switch having improved locking actuator|
|US5239143 *||Jun 28, 1988||Aug 24, 1993||Judco Manufacturing, Inc.||Rocker switch operator means|
|US7007712||May 10, 2005||Mar 7, 2006||Gary Anderson||Pneumatic tool lock|
|US7317263||May 10, 2005||Jan 8, 2008||Gary Anderson||Power tool lockdown device|
|US7750509||Dec 27, 2007||Jul 6, 2010||Gary Anderson||Power tool lockdown device|
|US20050247348 *||May 10, 2005||Nov 10, 2005||Gary Anderson||Pneumatic tool lock|
|US20050248893 *||May 10, 2005||Nov 10, 2005||Gary Anderson||Power tool lockdown device|
|US20140346026 *||Apr 7, 2014||Nov 27, 2014||Omron Corporation||Switch and control method thereof|
|U.S. Classification||200/43.1, 70/203, 70/204|