FR2544780A1 - Improvement to spring locks - Google Patents

Abstract

Improvement to spring locks by the production of a cage, the tongue 1 of which is retractable and equipped with a stud 1a which engages into a recess 8 of the beards of the bolt 9, temporarily blocking the latter when this tongue is subjected to an abnormal push as a consequence of an attempt to break in. Springs 6 ensure return of the tongues so as to project and thereby the retraction of the stud 1a under normal operating conditions.

Description

 The present invention is an improvement to locks with pumps and more particularly to the lantern, movement transmission member to the bolt. The operating principle of pump locks has been known and used for a long time. To better situate the invention we will briefly recall its elements.

 A pump lock is essentially constituted by an element of rectangular shape called a groove box which can rotate and move in translation against the action of an opposing spring. in a cylindrical recess called cannon.

 This groove box comprises a stack of plates which can pivot around an axis, recalled to a neutral position by an individual spring, which constitute the grooves. These grooves have a variable profile at one end, determined according to the combination of the key. The other end is provided with grooves. The introduction of the key into the groove box causes the grooves to tip over as a function of the notches in the key bringing the grooves into alignment, if the specific profile of each groove is related to the corresponding notch in the key.

 Under these conditions a pressure on the key will cause a translation of the grooved box by compressing a return spring, allowing the grooves thus aligned to engage in a prominent tongue of the lantern.

 The rotation of the lantern driven by the key through the throat box, will set in motion the bolt by arms secured to the lantern acting on a crenelagestaillé therein. This design has drawbacks, in particular at the level of the lantern, a member for transmitting movement between the key and the bolt via the groove box.

 Indeed, by inserting into the lock a false key corresponding more or less to the code, or even a blade of the same width, and by striking violently on these thus engaged, there will be a crushing of the throat box. releasing from the stopper provided on the barrel. Furthermore the grooves will be embedded in the tongue of the lantern by stamping, which can therefore be driven in rotation and set in motion the bolt.

An incomplete solution has been developed which consists
designing the lantern with a tongue press-fitted into its tray was circulating, and extending by a heel. Under too great a force transmitted by the grooved box, the tongue would retract projecting the heel which would engage in a recess provided for this purpose of the crenellation of pene (beards of the pèze), blocking it definitively.

 This design has the disadvantage of entailing the need for total destruction of the lock for opening the door after an attempted violation.

 The object of the present invention is to remedy these drawbacks by a new design of the lantern.

 This lantern will be made with a movable tongue recalled by springs and comprising at the rear a circular stud which engages in a recess of the bolt when the tongue is subjected to a push, thus temporarily blocking the bolt.

 This lantern design protects the lock from any picking attempts; which consists in trying to open by a non-destructive means by aligning the grooves by pressing on the tongue of the lantern or chin. To do this it is necessary to have a fulcrum and in the case of a crimped lantern we can very well press the throat box against the lantern which serves in the circumstance of the stop, without pushing it in, it is enough simply to maintain what will allow you to be able to work throat by throat, long and tedious work requiring unparalleled dexterity.

 The lantern object of the invention prohibits this attempt because the slightest pressure on the tongue 1 t will strengthen by blocking the bolt as long as the force acts on that ei.

 The description which follows, with reference to the appended drawings, of a non-limiting example of execution of such a lantern will make it possible to understand clearly how the invention can be put into practice.

 Figure l is a front view of the lantern where we see the tongue l.

 Figure 2 is a section along Il-Il of the previous one, showing the body of the lantern 3, and the plate 2 screwed on it. The arms 4 of the lantern secured with heels 4a are also held on the body of the lantern by screws. The springs 6 ensuring the projection of the tongue and the retraction of the stud la.

 Figures 3 and 4 show in partial section the lock respectively showing the tongue 1 in neutral position (rest), and pressed by the pressure of the misaligned grooves 7 of the groove box projecting the stud la which engages in the recess 8 of the beard of the pene 9.

 FIG. 5 shows the aliasing 10 of the beard of the bolt 9, producing the translation of the latter by the rotation of the arms 4 of the lantern. When the box with grooves receives a push by a false key or a blade 11, the grooves, whose lateral grooves are not in alignment, impress an effort on the tongue l of the lantern which retracts by compressing the opposing springs 6 and push the stud la into the recess 8 of the bolt, blocking the latter.

 To proceed with the opening of the door after attempted break-in, it will suffice to remove the grooved box (by drilling or cutting the barrel) to allow the tongue to return to its original position under the force of the springs 6 ce which will result in releasing the nipple which blocks the latch. The possible rotation of the lantern can be carried out using brown flat pliers, for example. Repairing the lock will therefore be limited to replacing the barrel and the throat box with the corresponding keys.

Claims (2)

 1. Lantern for pump lock characterized by a retractable tongue (1) held projecting by the pressure of springs (6).  2. Lantern for pump lock characterized by a retractable tongue and comprising a stud (la) which can engage in a recess (8) of the bolt beard (9) temporarily blocking the latter, when an abnormal pressure acts on the tongue (1) which retracts by compressing the return springs (6).