US3022408A

US3022408A - Electrically heated key

Info

Publication number: US3022408A
Application number: US64806A
Authority: US
Inventors: Robert W Wagner
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-10-25
Filing date: 1960-10-25
Publication date: 1962-02-20
Anticipated expiration: 1979-02-20

Description

Feb. 20, 1962 R. w. WAGNER 3,022,408

ELECTRICALLY HEATED KEY Filed Oct. 25, 1960 FIG.4

INVENTOR. ROBERT W WAGNER ATTORNEYS United States Patent Office 3,022,408 Patented Feb. 20, 1962 ELECTRICALLY HEATED KEY Robert W. Wagner, 1102 Lowenhill St., Pittsburgh, Pa. Filed Oct. 25, 1960, Ser. No. 64,806

6 Claims. (Cl. 219-49) This invention relates to a device for both thawing and unlocking frozen locks, and more particularly to a key having an electrical heating element therewithin for facilitating the opening of frozen locks.

Past endeavors to overcome the problem of opening frozen locks have included devices for surrounding the entire lock structure with integrally formed heating elements, heating the key in a separate furnace-like apparatus prepearatory to inserting it Within a lock, and inserting a small and ineffective wire-like heating element within the lock before applying the key thereto. None of the above previously suggested devices are completely satisfactory, however, due to one or more disadvantages inherent in each. For instance, where the lock, itself, is supplied with a heating element integrally therewith, the heating element is not normally energized until the key isfully inserted Within the lock. Therefore, where the look entrance, itself, is frozen, it is impossible to even insert the key within the lock and accordingly the heating element cannot be energized. Further, such installations are costly, since each lock must be provided with a heating element in close proximity to the tumblers, special insulation about the heating element, and special electrical installation for energizing the heating element.

Where the separate heating apparatus is employed to firstheat .the' key before inserting it within the look, not only is a time delay encountered while the key is being heated within the separate unit, but also a large portion of the residual heat of the key is lost when it is being transferred from the heating unit to the lock. Further, when the lock is badly frozen, it is necessary to re-heat the key several times in order to thaw out the lock, thus entailing 'a rather time-consuming and exasperating operation.

When the thin wire-like heating element device is utilized to thaw out a lock preparatory to the insertion of a key, the wire forming the heating element does not simultaneously fully contact the entire interior surface of the lock, since the wire, by necessity, must be quite thin so as to fit a plurality of different locks. Accordingly, in order to thaw out all of the tumblers, it is necessary to re-position the heating element within the lock several times. Further, due to the'extremely small mass involved in the Wire heating element, -a rather lengthy time is necessitated in order to completely thaw out the lock before inserting the key. Then too, it will be apparent that this procedure requires a two-step operation of first inserting a heating element and then quickly inserting a key before the lock has had an opportunity to refreeze.

I have found that optimum thawing conditions for frozen locks areobtainable by supplying a heating element directly within the nose of a key in such a manner so that the element transmits heat through the nose of the key and into the lock, thus permitting the lock to be quickly and efiiciently thawed out and opened in one operation.

It thus has been an object of my invention to provide a simple and efiicient device for overcoming the problems heretofore involved in freeing frozen looks;

A further object of my invention has been to provide a new article of manufacture which may both thaw and open a frozen lock;

An additional object of my invention has been to provide an electrically heated key for thawing and unlocking frozen or jammed locking devices;

A still further object of my invention has been to pro vide a standard key with an electrically resistant portion connected to a source of electrical power wherein the resistant portion transforms electrical energy into heat energy to thaw out a lock;

Another object of my invention has been to provide a key with an electrically resistant heating element in the nose portion thereof for transmitting heat through the key to the internal mechanism of a lock, and with a disc portion adjacent the back end of the nose portion for transmitting heat from the key to the end of the look cylinder in which the key is inserted.

These and other objects of my invention will be apparent to those skilled in the art from the following disclosure and accompanying drawings in which:

FIGURE 1 is a perspective view of an electrically heated key embodying my invention;

FIGURE 2 is an enlarged sectional view of the key taken along lines 2-2 of FIGURE 1;

FIGURE 3 is a sectional view in elevation on the 7 same scale as FIGURE 2 and taken along lines 3-3 of FIGURE 2; and

FIGURE 4 is a sectional view in elevation on the same Scale as FIGURE 2 and taken along line 4-4 of FIGURE 2.

I have found that a definite need still exists for a solution to the problem of frozen locks. Utility companies, for example, such as electric companies, gas companies, and railroads, have many sub-stations, pumping stations, inplement housings, and other such outposts, which must be periodically checked by service and maintenance personnel. These sub-stations or outposts are necessarily kept locked, and it is common practice for such companies to utilize a standard lock on each of its sub-stations so that the service or maintenance person nel need only utilize one master key to open all of the facilities Within their charge. Although integral locks may be utilized, padlocks have been found to be the most economical means for locking these outposts, especially since it is desirable to periodically change the locks. Since the locks are necessarily exposed to the weather, they readily become frozen during the inclement winter months, and impede accessibility to thesub-stations during that time of the year when the maintenance requirements are usually the highest.

To alleviate this problem, I have devised an electrically heated master key which may be utilized for the standard locks on all sub-stations or other such outposts in a certain area or Within the charge of certain designated personnel. The electrically heated key is easily portable, and may be adapted to operate from portable cells, an automobile battery, or a standard household outlet. When the key is operated from an automobile battery, I have found that it is convenient to mount a self-winding spool adjacent the battery for facilitating the feeding: out and reeling-in of the leads connecting the key to the battery. 1

Referring now to the drawings, a key 10 embodying my invention has a handle portion .11 and a shank or nose portion 12. A disc or plate member 13 is provided on a back portion of the shank 12 adjacent the handle: portion 11, and may either be formed integrally with the key 10 or welded thereon such as shown at w in FIG- URE 2.

A longitudinally-extending slotted or grooved portion 14 is formed in the shank or nose portion 12, and as shown particularly in FIGURES 2 and 4, may extend completely therethrough. An electrically resistant heating element 15 formed of any suitable high resistant material, such as nickel-chrome alloys, is positioned within the slotted porton 14. One end of the heating element is secured at 16 to a forward end of the slotted portion 14, such as by crimping, welding, or soldering.

A cut-out or recessed portion 17, formed in a forward portion of the handle portion 11, communicates with the groove or slotted portion 14. As shown particularly in FIGURE 2, the rearward end of the heating element 15 projects Within the recessed portion 17 and is connected to an end of an electrical lead 18, such as by welding or soldering. The lead 18, having an insulated cover 13', also extends into the recess 17. An insulating cement or mastic material 19 not only surrounds and insulates the rearward end of the heating element 15 and the connection between the heating element and the lead 18 from the key body, but also retains the rearward end of the heating element in position within the recess 17. Accordingly, the rearward end of the heating element 15 and its connection with the lead 18 are electrically insulated from the key, proper, so that current cannot pass directly between the rearward end of the heating element and the body of the key. As can be seen from the drav ing's, and particularly FIGURES 2 and 4, the heating element 15 is positioned within the slotted portion 14 in such a manner so that it does not contact the key along its extent, but only at the forwardconnection 16. v

A switch contact 20 projecting outwardly from a side face of the handle portion 11 extends inwardly into a recess 20 formed within the handle portion. An electrical lead 21 having an insulating cover 21 also extends within the recess 20 and is suitably connected to the switch contact 20. Insulating material 22,- pos'itioned within the recess 20, surrounds and insulates the connection between the switch contact 20 and the lead 21 and the contact 20 from the body of the key.

A resilient U-sha'ped switch 23 is secured along one leg 24, such as by welding or soldering, to a side of the handle body. An opposite side leg 25 is normally resilieritly urged in an open or outwardly-spaced-apart position from the switch contact 20, as shown in full lines in FIGURES 2 and 3. The switch, however, may be closed by compressing the leg 25 inwardly into engagethem with the switch contact 20 as shown in chain lines in FIGURES 2 and 3. The leg 25 is provided with an insulated cover member 26.

The key 10 may be provided with a standard hole 27 extending through the handle portion 11. The

leads

18 and 21 are connected to opposite sides of a suitable source of electrical power and may enter a rearward portion of the key along a grooved or recessed portion 28 formed in the handle portion 11. The lead 21 then passes through the hole 27 into the recess 22 wherein it is connected to the switch contact 20-. The lead 18 extending forwardly to the rearward portion of the heating element 15 may lie within a groove 29 also formed in the handle portion 11. The handle portion has an outer layer of insulating material 30 which may either be of a rubber-like composition of a ceramic material. If desired, the leads 13 and zrmay be imbedded within the insulating material 30 of the handle portion 11 instead of being positioned within the

grooves

28 and 29 formed in the handle body. Also, the rearward face of the disc 13 may be provided with insulating material to direct the heat forwardly and to further protect the user from the heat of the key.

In operation, with the leads connected to a suitable source of electrical power, the key may be inserted within the lock before closing the switch, or, more preferably, the switch is closed as soon as the key is grasped and then inserted within the lock. I have found that after the switch is closed, the heating element reaches a cherry red temperature in about five seconds. When the switch is closed, current passes from inlet lead 21 through the contact 20, the switch 23, forwardly through the nose portion 12 and backwardly through the heating element 15 to outlet lead 18. The heat derived from the heating element is transmitted through the nose of the key and contacts all of the tumblers in the lock simultaneously so that the internal mechanism of the lock receives an even distribution of heat from the key, thus quickly and efiiciently thawing it out. In addition, the disc or plate member 13, being formed of a good heat conductor such as brass or copper, transmits heat from the shank of the key to the end of the cylinder in which the key is inserted, thereby greatly enhancing the thawing of the lock.

Although I have disclosed and described a preferred embodiment of my invention, it will be apparent to those skilled in the art that various changes and modifications may be made thereto without departing from the spirit and scope of the invention, as defined in the appended claims.

What I claim is:

1. An improved key for both thawing-out and unlocking a frozen lock comprising a handle portion, a nose portion and a heat conductive disc member formed on said nose portion adjacent said handle portion, a slotted portion extending longitudinally along said nose portion, a heating element positioned within said slotted portion, means for connecting said heating element to a source f electrical power, and a switch secured to said handle portion and forming a part of said means for energizing said heating element to heat the nose of said key and said heat conductive disc member for efficiently transferring heat to the tumbler and lock cylinder of a frozen lock.

2. An improved key for both thawing and unlocking a frozen lock comprising a handle portion, a nose portion, and a disc member of heat conductive material formed on said nose portion adjacent said handle portion with a forward face of said disc member being normal to the longitudinal axis of said nose portion, a longitudinally-extending slotted portion formed in said nose portion, a recess formed in said handle portion adjacent said slotted portion, an electrically resistant heating element positioned within said slotted portion with one end of said heating element being secured to said nose portion at the forward end of said slotted portion, and the other end of said heating element projecting into said recessed portion, means projecting within said recessed portion for connecting said other end of said heating element to one side of a source of electrical power, means for electrically insulating said other end of said heating element from the body of said key, means connecting said one end of said heating element to an opposite side of the source of electrical power, and said heating element, except for its connection with the forward end of said slotted portion, being spaced-apart from said nose portion along its extent.

3. An improved key assembly for both thawing and unlocking a frozen lock comprising a handle portion and a nose portion, a heat conductive disc member formed on said nose portion adjacent said handle portion, an electrically resistant heating element positioned within said nose portion for heating both said nose portion and said disc member to transfer heat simultaneously to the tumblers and end face of a lock cylinder, said. heating element being electrically connected to said key solely at a forward end of said nose portion, means forming a circuit for connecting said heating element to opposite sides of a source of electrical power, said means comprising an electrical conduit connecting one side of the source of electrical power to a rearward end of said heating element, a normally open switch secured to one side of said handle portion, a second electrical conduit connecting the other side of the source of electrical power to a switch contact insulatably positioned on said handle portion, and said switch when in a closed position completing the circuit between the source of power and said heating element so that current may flow through the switch, the nose of the key, and the heating element to thereby energize said heating element.

4. An improved key assembly as defined in claim 3 wherein said electrical conduits formed in said handle portion.

5. An improved key assembly as defined in claim 3 wherein outer surface portions of said handle portion are of insulating material to protect the user from both shock and heat.

6. An improved key for both thawing and unlocking a frozen lock comprising a handle portion, a nose portion, and a heat conductive member secured to said nose portion adjacent said handle portion for contacting and heating the end face of a lock cylinder, a heating element positioned within and extending along said nose extend along recesses UNITED STATES PATENTS 944,382 Ross Dec. 28, 1909 2,538,872 Jones Jan. 23, 1951 2,774,855 Simmons Dec. 18, 1956 2,863,036 Mitchell et a1. Dec. 2, 1958 2,965,741 Blazina Dec. 20, 1960