EP1061209A1 - Latch bolt for lock fitting and manufacturing method thereof - Google Patents

Abstract

Lock fitting comprises metal head (9) molded onto bolt shank. Side (10) defines ramp (11) for drawing back control of bolt in its unlocked position against spring under impulse of strike plate. Shank is covered by insert (12) made of synthetic material which absorbs noise of bolt clashing with strike plate. Insert is installed on end of bolt before molding on metal shank. An Independent claim is also included for the manufacturing method of half-turn bolt.

Description

The invention relates to a latch bolt for hardware lock type lock, lever-lock or similar comprising a head molded onto a bolt tail and one of which side defines a ramp for the reverse control of this bolt U-turn in the unlocked position, against the action of elastic return means, at the instigation, in particular, of a keep provided designed to accommodate said latch bolt, said head being furnished, at least on its side defining the ramp, with a insert made of a material, in particular synthetic, defined suitable for dampen, at least in part, the noise of a collision between said turn around with said strike. The invention further relates to a method of manufacturing such a latch bolt.

The present invention will find its application in the field of the building hardware.

Many locking fittings, of the lock type, lock-bolt or similar, are provided, among other things, with a U-bolt which is self-retracting in the locking, this under the impulse of return means elastic. In this position this U-bolt is provided at even to cooperate with a keeper to maintain an opening of door or the like in the closed position on its sleeping frame.

More specifically, a control member, in particular, a control handle allows, when opening this door, ensure the retraction of this latch bolt into a position erased inside a case and, therefore, released from the strike in which it was previously introduced. Then, once the open leaf and the action on said control handle released, this U-bolt regains via the elastic return means, its initial, projecting position, locking.

Conversely, when the door is closed, the user has the possibility, through this same handful of command, to ensure, again, the retreat of this latch turn to release the action on this handle only once the closed leaf, i.e. in a position such that this U-bolt can come freely into the corresponding keeper placed on the frame.

However, such a latch bolt has a head, one side of which is biased so as to define a ramp which, when it comes on contact with the strike on the frame, causes automatically reversing against the action of the recall means elastic. Then, when this head of the latch bolt is to the right of the opening planned to accommodate it in the keeper, it is automatically pushed back into the latter in locking position.

Therefore, by slamming the sash against the frame sleeping to close the door, it is guaranteed to be kept closed thanks to the peculiarities of operation of said U-bolt.

However, such a door slam, whether voluntary or involuntary, causes a certain noise which, at times, can be amplified through poorly soundproofed premises. Now, a much of this door slamming noise results from impact of the head of the latch bolt, metallic type against the striker itself designed, often, of metallic material.

In this regard, it is already known, in particular by the document DE-U-298 19 889 a latch bolt head receiving, on its bevelled part, a pellet or an insert of material to low coefficient of friction, for example in polyamide, coming to be housed in an appropriate recess made at the level of this beveled part. Such a pellet is defined, here of interchangeable nature and its maintenance at the level of the head of the U-bolt is ensured through the tail of the latter, once the head has been added, by mechanical connection means, on this tail.

Similarly, it is known from document US-A-2,159,315 a bolt U-turn whose head is successively enveloped by a rubber membrane then by a protective envelope made of elastic material. In fact, this envelope of protection is provided capable of absorbing shocks with the strike, this shock being, moreover, absorbed by the membrane in rubber, so that it is not transmitted to the opening of the door. Note that the body of said U-bolt comprises, on its opposite sides and transverse to its axis, grooves in which are housed retaining tabs associated with the protective envelope, while wedging it, the rubber membrane.

We will also cite the document CH-A.384.401 which concerns, a lock fitting of the lock type, provided with a latch bolt whose head, made of synthetic material, in particular nylon, is secured to the tail of this latch bolt, which is made of metal, by means of rivets in synthetic material.

Finally, this head of the latch bolt is made completely made of synthetic material, which poses the problem of its mechanical strength over time, either it receives, by a additional mounting operation, a protective piece in synthetic material. Obviously, such a room is, then, likely to come off unexpectedly from this bolt head U-turn, risk which is all the greater as the shocks, resulting from the meeting of said latch bolt with the keeper at when a door is closed, are cashed directly by this protective part.

The invention, as characterized in the claims, solves this problem and consists of a latch bolt for hardware lock type lock, lever-lock or similar comprising a head molded onto a bolt tail and one of which side defines a ramp for the reverse control of this bolt U-turn in the unlocked position, against the action of elastic return means, under the impulse, in particular of a keep provided designed to accommodate said latch bolt, said head being trimmed, at least on its side defining the ramp of a insert made of a material, in particular synthetic, defined suitable for dampen, at least in part, the noise of a collision between said latch turn with said strike, said insert being defined suitable to be mounted on the end (6) of the front bolt tail overmolding, on this end of the metal head.

• à rapporter sur l'extrémité d'une queue de pêne un insert en un matériau, notamment synthétique, apte à amortir le bruit d'un entrechoquement ;
• à surmouler sur cette extrémité de la queue de pêne et sur cet insert la tête métallique de ce pêne demi-tour.

The invention relates to a method of manufacturing such a latch bolt consisting of:

• inserting on the end of a bolt tail an insert made of a material, in particular synthetic material, capable of damping the noise of a collision;
• to be molded on this end of the bolt tail and on this insert the metal head of this latch bolt.

• la figure 1 illustre, de manière schématisée, une porte dont l'ouvrant est équipé d'une ferrure de verrouillage pourvue d'un pêne demi-tour destiné à coopérer avec une gâche au niveau du cadre dormant ;
• la figure 2 est une représentation schématisée en perspective du pêne demi-tour et en particulier de sa tête ;
• la figure 3 est une représentation schématisée et en élévation du pêne demi-tour, conforme à l'invention ;
• la figure 4 est une vue schématisée et de dessous de la figure 3.

The invention will be better understood on reading the description which follows and in view of the attached drawing:

• Figure 1 illustrates, schematically, a door whose opening is equipped with a locking fitting provided with a latch bolt intended to cooperate with a keeper at the frame;
• Figure 2 is a schematic perspective representation of the latch bolt and in particular of its head;
• Figure 3 is a schematic representation in elevation of the latch bolt, according to the invention;
• FIG. 4 is a schematic view from below of FIG. 3.

As visible in the figures of the attached drawing, this invention relates to the field of locking fittings 1 of type lock, bolt lock or similar.

In fact, it relates to a spring return bolt 2 in the locked or semi-locked position.

Such a U-bolt 2 is capable of being actuated by through a control device, in particular a control handle 3, or even a key element 4.

Thus, it has been represented, as an example in FIG. 1, a door whose opening 5 accommodates such a fitting of lock 1 in the form of a lock. More specifically, it is visible at the height of the front edge 6 of this opening 5 the U-bolt 2 which, in a natural position of rest, is prominent due to elastic return means (not represented) to which it is subject.

This U-bolt 2 is brought to cooperate, in the position of door closing, with a strike 7 installed at the level of the sleeping frame 8.

Note, in this regard, that the latch bolt 2 has a head 9 including one side 10, oriented in the direction of the sleeping frame 8, defines a ramp 11 which ensures the back-up control of this latch bolt 2, in its unlocked position, against the action of elastic return means, this under the impulse of said strike 7, when closing the door without user intervention on any of the control elements 3, 4.

Insofar as the head 9 of this latch bolt 2, just like the strike 7 at the level of the sleeping frame 8 are designed, usually, in metallic material, their meeting produces an annoying rattling noise.

Also, to remedy this problem, this head 9, made of material metal, the latch bolt 2 is fitted, at least on its side 10 defining the ramp 11, of an insert 12 made of a material, in particular of synthetic type, defined capable of damping, at least in part, this noise resulting from the collision of said bolt U-turn 2 with said strike 7.

As shown in Figures 2, 3 and 4, to ensure the function assigned to it, this insert 12 is presented slightly protruding at ramp 11. If necessary, it can still extend at the edge before 13 of this head 9 of the latch bolt 2 so that, until the engagement in keeper 7, this head 9 is in contact with the latter at through its insert 12.

Preferably, the implantation of the insert 12 at the level of the head 9 of the U-bolt 2 results from a method of overmolding.

We will note in this regard and as visible in Figures 3 and 4 of the attached drawing, which a U-bolt 2 comprises, not only a head 9, but also a tail 15 provided on the same to extend into the housing of the locking fitting 1, on this tail 15 coming to act, in particular, the organs of control such as the handle 3 or the key element 4 by through an appropriate control mechanism. In fact, it is very common for head 9 to be molded onto tail 15 which is therefore also in the form of a insert in the injection mold.

Also, according to the invention, the insert 12 is defined capable of being mounted on the end 16 of this bolt tail 15, before one comes to overmold, on this end 16, said head 9 metal of this latch bolt 2.

By way of example, this end 16 of the bolt tail 15 can be cylindrical in shape. Insert 12 can include, in this case, a rear wall 19 in which is provided a receiving opening for this end 16. By elsewhere, to promote the connection with the head 9 which is comes to mold, this end 16 of the tail 15 can possibly be striated in the axial direction, while the opening in the rear wall 19 of the insert 12 can, from its side, be grooved to guarantee their immobilization in rotation relative to each other before the operation of overmolding.

Obviously, the present invention is in no way limited to such a mode of connection between an insert 12 and the end 16 a bolt tail 15.

As already indicated above, such an insert 12 can, not only, extend along this ramp 11, but still at the level of the front edge 13 of the head 9, or even on the opposite side 17 to said ramp 11.

In summary and as visible in FIG. 3, this insert 12 can borrow, in section, the shape of the head 9 while being slightly higher than the latter so that play its role as a noise absorber by coming into contact, first, with strike 7. Note, however, the presence a recess 18 in the central part of this insert 12 of so as to allow the flow on either side of this last, molten metallic material when molding the metal head 9.

In this regard, it will be observed that this process of overmolding a metallic material with high melting temperature on an insert synthetic material whose melting or degradation is much lower seems a priori of implementation difficult if not impossible work. On the one hand, it turns out that through a very rapid injection into the mold of the molten metallic material, injection which can be followed, instantly, cooling the mold and, secondly, because of the generally reduced thermal conductivity of a synthetic material, resulting in a certain inertia in the rise in temperature of the latter, we knew master this overmolding process, a priori impossible to achieve.

Claims (4)

Latch bolt for lock type lock fitting, cremone bolt or the like comprising an overmolded head (9) on a bolt tail (15) and one side (10) of which defines a ramp (11) for the reverse control of this latch bolt (2) in unlocking position, against the action of return means elastic, under the impetus, in particular, of a keeper (7) provided able to accommodate said latch bolt (2), said head (9) being lined, at least on its side (10) defining the ramp (11), an insert (12) made of a material, in particular synthetic material, defined able to dampen, at least in part, the noise of a knocking of said latch bolt (2) with said strike (7), characterized by the fact that said insert (12) is defined capable of be mounted on the end (16) of the bolt tail (15) before overmolding, on this end (16), of the metal head (9). Latch bolt according to claim 1, characterized by fact that the insert (12), equipping the end (16) of said bolt tail (15), is defined to be of identical section while being slightly higher than that of the head (9). Latch bolt according to any one of claims 1 or 2, characterized in that the insert (12) comprises, in its central part, an obviously (18) allowing the flow of molten metallic material during molding of said head (9). Method for manufacturing a latch bolt according to any one of the preceding claims, characterized in that: is reported on the end (16) of a bolt tail (15) an insert (12) of a material, in particular synthetic capable of damping a rattling noise; is molded on this end (16) of the bolt tail (15) and on this insert (12) the metal head (9) of this latch bolt (2).

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