Abstract:
A laminated padlock includes a J-shaped shackle with a U-shaped locking plate and a T-shaped locking plate, the leg of the T-shaped locking plate being slidably fitted between the spaced legs of the U-shaped locking plate.

Description:
The present invention relates in general to padlocks of the type having double locked shackles, and it relates in particular to a laminated padlock having a new and improved locking slide construction. 
     BACKGROUND OF THE INVENTION 
     Padlocks in which a pair of locking members are slidably mounted for reciprocal movement into and out of respective notches in the heel and toe portions of a J-shaped shackle are well known in the art. See, for example, U.S. Pat. Nos. 3,475,930 and 3,979,931. U.S. Pat. No. 4,098,100 describes a laminated padlock having a pair of coplanar slides for double locking the shackle and also having a safety rotator which overlies the inner end of the lock barrel and drivingly connects it to the locking slides. This safety rotor is designed to prevent picking of the lock by means of a tool inserted through the key slot in the lock barrel. 
     SUMMARY OF THE INVENTION 
     Briefly, there is provided in accordance with the present invention a new and improved laminated padlock which incorporates a U-shaped locking and an interfitting T-shaped locking slide to provide a smoother operating and more reliable lock. In addition, in one embodiment of the invention a heavy duty safety rotator couples the lock barrel to the locking slides and enables operating thereof by rotating the lock barrel in either the clockwise or counterclockwise direction. In another embodiment of the invention an integral extension on the lock barrel operatively connects to the locking slides. 
    
    
     GENERAL DESCRIPTION OF THE DRAWING 
     Other aspects of the present invention and a better understanding thereof will be better understood by a reading of the following detailed description taken in connection with the accompanying drawings wherein: 
     FIG. 1 is a side view, partly in cross-section of a padlock embodying the present invention; 
     FIG. 2 is a cross-sectional view of the padlock of FIG. 1 taken along the line 2--2 thereof; 
     FIG. 3 is a cross-sectional view of the padlock of FIG. 1 taken along the line 3--3 thereof; 
     FIG. 4 is a cross-sectional view of the padlock of FIG. 1 taken along the line 4--4 thereof; 
     FIG. 5 is a side view, partly in cross-section, of a padlock constituting another embodiment of the invention; and 
     FIG. 6 is a cross-sectional view of the padlock of FIG. 5 taken along the line 6--6 thereof. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1-4, a padlock 10 comprises a body 12 made up of a plurality of laminated body plates 14, a J-shaped shackle 16, a key-operated lock barrel or cylinder 18, and a locking mechanism including a pair of locking slides 20 and 22 which are operatively connected to the lock barrel 18 by means of a safety rotator 24. The locking slides 20 and 22 are respectively biased outwardly into a pair of notches 26 and 28 in the shackle 16 by means of a single coil spring 30. The shackle 16 has a short leg portion having the notch 28 near the distal end thereof and a longer leg portion having the notch 26 at an intermediate location therein. A coil spring 32 is compressed between the heel end of the shackle 16 and the lowermost end plate 14 of the body 12. An external annular flange 34 at the heel of the longer leg of the shackle 16 prevents complete removal of the shackle 16 from the body 12 inasmuch as the outer diameter of the flange 34 exceeds the inner diameter of the hole 36 through the body plate 14a. 
     The lock barrel 18 is rotatably mounted in a lock body 40 located in a cavity near the bottom of the laminated body 12 and held in place therein by the lowermost body plate 14. The lock body 40 also supports a plurality of tumblers 42 which, as is well known to those skilled in the art, are moved radially outwardly when a key 44 is inserted into the key slot in the lock barrel 18. When the proper key is placed in the key slot the tumbler pins are so positioned as to permit rotation of the lock barrel 18 within the lock body 40. 
     The lock barrel 18 is provided with an upwardly protruding drive finger 46 which extends into a correspondingly shaped hole in the generally sylindrical body portion 48 of the safety rotator 24. The safety rotator 24 is further provided with an upstanding generally rectangular drive flange 50 which extends diametrically across the circular upper surface of the safety rotator. Rotation of the barrel 18 by means of the key 44 thus results in a corresponding rotation of the safety rotator 24 and the drive flange 50 thereon. 
     The locking slide 20, as best shown in FIGS. 2 and 3, is generally U-shaped and has a pair of parallel leg portions 54 and 55 connected together by the locking slide 22 which is T-shaped and has a central leg 58 which is coplanar with the legs 54, 55 and is slidably disposed therebetween. It may thus be seen that the leg 54 is guided by the legs 54 and 55 to assure smooth and wearfree operation. The leg 58 is provided with an axial blind hole 60 which receives one end of the coil spring 30 and a similar blind hole 62 is provided in the base portion of the slide 20 and receives the other end of the spring 30. A pair of rectangular flanges 66 and 67 depend from the distal end portions of the legs 54 and 55 respectively of the U-shaped locking slide 20, and a rectangular flange 69 depends from the distal end of the leg portion 60 of the locking slide 22. The inner surfaces of the flanges 66, 67, and 79 constitute cam follower surfaces which are engaged by the drive flange 50 of the safety rotator 24 to withdraw the locking ends of the slides from the notches 26 and 27 in response to rotation of the safety rotator 24 in either a clockwise or a counterclockwise direction. 
     With reference to FIG. 3, it may be seen that rotation of the safety rotator in a clockwise direction will cause the drive flange 50 (not shown in FIG. 3) to engage the inner surface of the flange 66 on the upper leg of the U-shaped slide to move the slide toward the right out of the notch in the shackle 16 and simultaneously to engage the inner surface of the flange 69 at the lower end to move the locking slide 22 inwardly toward the left and out of the respective notch in the shackle 16. 
     It may thus be seen that the locking slides 20 and 22 are coplanar and are held in the coplanar position by the body plates located directly and below them. They are biased into the locking position by means of a single coil spring 30 and they provide mutually coacting slide surfaces for guiding the slide members for rectilinear motion towards and away from the respective legs of the chackle 16. 
     In the embodiment of the invention shown in FIG. 1 the safety rotator 24 has an elongated cylindrical body portion 48 and a relatively short drive flange 50 at the top. 
     In order to reduce the manufacturing cost of a padlock embodying the present invention, the safety rotator may be eliminated and replaced by an integral extension of the lock barrel itself. Such a padlock is illustrated in FIGS. 5 and 6 and may be seen to include a key-operated lock barrel 70 having an integral rotor 72 extending longitudinally from its inner and between the depending flanges 66 and 69 on the locking slides 20 and 22. 
     An intermediate body plate 74 extends into the space 76 between the lock barrel 70 and the locking slides to prevent insertion of a picking tool through the key slot into engagement with the locking slides for ectuation thereof. As best seen in FIG. 6, the portion of the body plate 74 which extends into the space 76 is triangular, converging toward the rotor 72 so as not to interfere with the normal turning thereof when the lock barrel is rotated with a key. 
     While the present invention has been described in connection with particular embodiments thereof, it will be understood by those skilled in the art that many changes and modifications may be made without departing from the true spirit and scope of the present invention. Therefore, it is intended by the appended claims to cover all such changes and modifications which come within the true spirit and scope of this invention.