Locks – Portable – Padlocks
Reexamination Certificate
1999-01-22
2001-10-23
Gall, Lloyd A. (Department: 3627)
Locks
Portable
Padlocks
C070S052000, C070S056000, C070S417000
Reexamination Certificate
active
06305198
ABSTRACT:
BACKGROUND OF THE INVENTION
Padlocks typically have a single locking mechanism, but some have dual locking systems to further protect the lock against forced entry. For example, U.S. Pat. No. 5,044,180 to Lebrecht shows a round padlock with a round shackle. A plug and cylinder lock operates the shackle via a primary drive prong. A secondary lock latch also locks the shackle, and is disengageable therefrom by a cam which is rotatable by the key. U.S. Pat. No. 4,998,423 to Hsu shows a similar structure.
These locks, however, are still susceptible to attack especially from a prying force applied to the shackle. When a foreign object is inserted into the shackle and the shackle is forced open, shear stress is placed upon the primary drive prong, the secondary lock, and the cylinder. If the cylinder fails first, then the cylinder can be rotated, moving the primary drive prong, disengaging the secondary lock, and opening the lock.
Several patents show locks with breakable elements disposed between a key-operable lock and a bolt, for example U.S. Pat. Nos. 5,611,225 to Resch and 5,548,981 to Kirk, but a need exists for a padlock where the shear stress created by a foreign object being inserted into either the shackle or the cylinder will be carried by the primary drive prong, causing it to shear first, protecting the cylinder and preserving the integrity of the padlock.
Attempts at providing additional protection from attack led to the use of protective shells placed over the padlock. For example, U.S. Pat. No. 5,146,771 to Loughlin shows a padlock with a shield into which the padlock may be inserted to deter forced attack. U.S. Pat. No. 4,567,740 to Kelly also shows a padlock provided with a housing for receiving and shielding the padlock. These padlocks, however, do not obscure a significant portion of the shackle, especially where it enters the padlock. Further, these shells are still susceptible to being pried away from the lock or allowing a prying member to attack the padlock directly or would necessarily have a loose fit, enabling the shell to slide off of the lock.
Therefore, the need still exists for a protective shell that can be easily, form-fittingly attached to a padlock, can obscure a portion of the shackle, can completely cover the underlying padlock, and contains seams that are not aligned with the seams of the padlock to further deter prying open of the padlock body.
Protection of the key holes of locks from elements has been provided by different mechanisms. For example, U.S. Pat. No. 2,874,563 to Schlage shows a keyhole shutter arranged in a housing that is to be attached to a door lock. The shutter itself includes opposed shutter-members that are coplanar and of the general form of segments of circles, having their straight edges in engagement. The periphery of the members is formed with a circumferential recess in which resides a C-shaped spring. In order to facilitate entry of a key between the edges, the edges may be chamfered inwardly.
Similarly, U.S. Pat. No. 952,643 to Roche discloses a spring loaded keyhole cover for a trunk-lock having segmental gates located in back of a circular opening formed in and concentric with the boss-like outer casing or shell of the lock. The outer shell confines the gates in a shallow concentric chamber formed between its inner face and the outer face of a corresponding boss-like inner shell. German Patent No. DT 1,780,397 to Hulsbeck discloses a keyhole cover having two semicircular halves meeting at a beveled common edge and a circumferential spring clip, and French Patent No. 638,078 to Hamon shows a spring loaded key hole cover.
Other locks have employed sliding keyhole covers, These sliding keyhole covers are shown, for example, in the Roche patent which also discloses a vertical and a horizontal sliding-plate gate. U.S. Pat. No. 116,972 to Madge shows a plate that can be slid over the key hole of a padlock, and U.S. Pat. No. 8,318 to Tilton discloses a padlock with a slide plate that can entirely cover or uncover the keyhole. U.K. Pat. No. 571,487 to Smith discloses a key-hole cover slidably engaged on a mounting plate that is attached to a padlock. In U.S. Pat. No. 1,062,594 to Isidor, a suitcase lock is provided with a escutcheon having a slidably disposed closing member with a knob to convert the keyhole, while U.S. Pat. No. 2,491,337 to Segal discloses a slidable guided latching member that has a circular head for covering the keyhole of a cylinder lock. U.S. Pat. No. 3,267,707 to Adams show a slide member having a disk-like body and a forwardly projecting rectangular knob portion that is held against the lock body by a retainer cap. The retainer cap includes a circular aperture, a vertical excursion to receive the knob, and a slide channel to receive the disk portion of the slide member.
SUMMARY OF THE INVENTION
The padlocks of the present invention have a steel lock body constructed of at least two protective shell layers. The shell layers are constructed of a plurality of sub-shells which when joined together form seams. The seams are aligned so as to alternate from one shell layer to the next so that no single seam passes from the outside to the inside of the lock body. As the shell seams are not aligned, the security of the locks is increased.
An exterior cushioning bumper is provided to fit around the outside of the lock body. The bumper is part of a modular system whereby the color and style of the bumper can be selected and coded to match the color of the key for the padlock. The bumper keeps water out of the padlock, allows condensed water to drain from the padlock through weep holes, prevents abrasion with the locked object that would normally occur through contact with the hard surfaces of the padlock, provides comfort in the hand of the user, and covers the seams and rivet holes in the padlock shell. The bumper includes a movable cover for the keyway in the lock body.
In some embodiments, the movable cover is a slideable cover that can include a first section of suitable dimensions to cover the keyway and a raised portion extending from the first portion for engaging the finger of a user. This cover is slideably disposed in the bumper between a first position covering the passage and a second position exposing the keyway.
In other embodiment, the cover is a spring loaded shutter mechanism that opens automatically upon insertion of the key. The cover has two semi-circular halves and a spring clip disposed in a slot that extends around the circumference of the two halves, biasing the halves together. The common edge of the two halves is beveled to enable a key to cam the halves apart, permitting the insertion of the key in the keyhole. The cover can rotate in this opening upon insertion and turning of the key.
The padlock includes a shackle which is associated with the lock body for movement between an open position for engaging releasing objects to be secured and a closed position for locking the objects. Preferably, the shackle is situated in an offset arrangement in the lock body to facilitate attachment to objects that are close to walls and doors.
The shackle is secured in the locked position by operative elements such as by a primary, key-operable lock drivingly connected to a shackle by a drive linkage. The drive linkage can include meshed gear teeth on the shackle and on a gear that is rotatable with the key. Alternatively, the drive linkage includes a cam arm that engages a slot in the shackle. A secondary lock is spring biased into another notch in the shackle. A cam associated with the lock cylinder of the primary lock disengages the secondary lock as the key is turned, permitting the shackle to be directed to an open position.
In order to prevent failure of the lock under a force applied against either the shackle or the lock cylinder of the primary lock, the drive linkage is constructed to be weaker than the structure of the primary lock, causing the drive linkage to fail, preferably by shearing, before the primary lock. A secondary lock provides additional security in the event of the failure
Adler Ari Tao
Chastain David Paul
Fiegener John Darrin
Finiw Maryann
Geringer Joseph Robert
Calfee Halter & Griswold
Gall Lloyd A.
Master Lock Company
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