Lock

Information

  • Patent Grant
  • 6213523
  • Patent Number
    6,213,523
  • Date Filed
    Friday, July 2, 1999
    24 years ago
  • Date Issued
    Tuesday, April 10, 2001
    23 years ago
Abstract
A lock has a holding bolt and a retaining member for yieldably retaining the holding bolt in its bolting and its release position and for positively preventing the bolt from withdrawal from the lock unless a fastening member attaching a forend of the lock to the lock case is at least partly released.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention concerns a lock having a bolting means for bolting a latch bolt.




2. Description of the Background Art




More precisely, this invention concerns a lock installable in, e.g., a door leaf. The lock includes a case and a latch bolt movable within the case between a locking position, in which the latch bolt at least partly projects from the case, and an unlocking position, in which the latch bolt is retracted within the case. Generally, a lock of this kind includes some kind of bolting means adapted to bolt the latch bolt in at least its locked position. Such bolting means is generally factory mounted on one side of the case for access from a corresponding side of a door. Consequently, to comply with possible customer needs, it is necessary to manufacture two locks having the bolting means on opposite sides of the case.




U.S. Pat. No. 5,779,287 discloses a lock having an optional bolting means, i.e., a bolting means that is separately delivered with the lock and that may be mounted in the lock by the user at need. This prior art lock includes a lock case having opposed walls and a latch bolt slidable between a locking position and an unlocking position. Each of the opposed walls is provided with an aperture for optionally receiving a holding bolt. The holding bolt is positionable in each aperture in a first, relatively retracted position allowing sliding of the latch bolt from its locking position to its unlocking position, and in a second relatively inserted position preventing sliding of the holding bolt from its locking position to its unlocking position. The optional bolting means further includes a spring for yieldably retaining the holding bolt in its first and second positions. The apertures are shaped such that once the holding bolt has been introduced in a selected aperture, it is automatically kept there by the spring pressing it towards a portion of the aperture preventing its withdrawal. However, withdrawal of the holding bolt is possible upon manually rotating it through a small, limited angle against the action of the spring. Since the free end of the holding bolt of this prior art lock needs to be axially and radially guided, the lock requires a relatively thick door leaf and particularly an escutcheon mounted onto the door leaf to guide the holding bolt and also to prevent its rotation and unintentional removal.




OBJECT OF THE INVENTION




A first object of the present invention is to provide a lock of the general kind stated preventing unintentional removal and allowing intentional removal of the holding bolt without rotational movement thereof. A second object is to provide such a lock needing neither a relatively thick door leaf nor an escutcheon to guide its holding bolt.




SUMMARY OF THE INVENTION




The first object stated above has been achieved in a lock including a lock case, a forend attachable to said case by means of removable fastening means, a latch bolt movable within said case between a locking position, in which it at least partly projects from the case, and an unlocking position, in which it is retracted within the case, a holding bolt having a defined cross section and being positionable in a first, relatively retracted position allowing movement of said latch bolt from its locking position to its unlocking position, and in a second relatively inserted position preventing movement of said holding bolt from its locking position to its unlocking position, and spring means for yieldably retaining said holding bolt in its first and second positions and for positively preventing withdrawal thereof from said case, wherein at least one portion of said spring means is movable between a first position, in which it prevents withdrawal of said holding bolt, and a second position, in which it allows withdrawal of said holding bolt, movement of said at least one portion from said first to said second position being enabled by at least partial removal of said fastening means.




The second object has been achieved in that said case accommodates a guide means having a guide aperture for guiding movement of said holding bolt, said guide aperture having a cross section adapted to said defined cross section, said at least one portion of said spring means extending across at least a portion of said aperture in said first portion of said spring means.











BRIEF DESCRIPTION OF THE DRAWINGS




Further objects and advantages of the invention will be apparent from the following non-limiting description of a preferred embodiment, reference being made to the annexed drawings, wherein:





FIG. 1

is a perspective side view of the lock having a holding bolt mounted therein;





FIG. 2

is a corresponding perspective view showing the lock of

FIG. 1

having one half of the lock case removed;





FIG. 3

is a partly sectioned side view at an enlarged scale showing the lock having the holding bolt removed and further showing the holding bolt retaining means in an active position;





FIG. 4

is a view corresponding to

FIG. 3

but showing the holding bolt retaining means in an inactive position;





FIG. 5

is a perspective view at an enlarged scale of a guide and ratchet member for the holding bolt; and





FIG. 6

is a perspective view at an enlarged scale of the holding bolt shown in FIGS.


1


and


2


.











DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT




The lock according to the present invention has a lock case


1


consisting of two equal halves


1




a


,


1




b


. The case includes two opposed side walls


2


and


3


, an upper wall


4


, a lower wall


5


, a front wall


6


and a back wall


7


. A forend


8


has two holes


9


and


10


for attachment of the lock to, e.g., a door leaf. Two screws


11


and


12


attach the forend to the front wall


6


. The forend also has a rectangular opening


13


through which a latch bolt


14


is slidable between a foremost, locking position, in which it projects from the case, as seen in

FIGS. 1

,


2


and


3


, and a non-shown, unlocking position, in which it is backwardly retracted within the case so as to leave its front edge


14


′ substantially flush with the forend


8


. The latch bolt has a recessed portion


15


forwardly defined by a shoulder


16


(FIG.


3


). In the backward direction a corresponding shoulder is divided in two shoulders


17




a,




17




b


separated by a slot


18


extending from the backward end of the latch bolt about half way to its forward end.




The latch bolt is operable by means of a follower


19


having a square hole


20


intended for insertion therein of a square rod connected to a handle for rotating the follower through a limited angle. A helical spring


21


having its coil


22


positioned about a lug


23


bent in from the side wall


3


has a first straight end portion


24


bearing on the inner side of the lower wall


5


and a second straight end portion


25


bearing on the shoulder


16


of the latch bolt, so as to urge the latter towards its locking position shown in

FIGS. 1

,


2


and


3


. As appears particularly from

FIG. 3

, the follower


19


is of the kind having two aligned wings


26




a,




26




b


abutting a respective one of the shoulders


17




a,




17




b.


This known arrangement ensures that a handle associated to the follower


19


may operate the latch bolt in both rotational directions of the follower against counteracting forces of the spring


21


.




In order to bolt the latch bolt so as to prevent movement thereof towards its open position there is provided a bolting means comprising a holding bolt


27


(FIG.


6


). The holding bolt is insertable through an L-shaped aperture


28


in wall


2


(

FIG. 1

) so as to at least partly extend through a corresponding aperture


28


′ in wall


3


(FIG.


3


). In its inserted state, the holding bolt is moveable between a relatively retracted, unbolting position and a relatively inserted, bolting position. The holding bolt


27


includes a straight, flat main portion having in one end a handle portion


29


and in its opposite, inner, or foremost end a guide portion


30


having an L-shaped cross section with a longer leg


31


(corresponding to the main portion) and a shorter leg


32


. The portion


30


includes a bolting member


33


extending past the main part of the shorter leg


32


. In the bolting position of the holding bolt, this bolting member is positioned in the path of movement of a rear surface


17


′ of the latch bolt


14


so as to prevent movement thereof towards its unlocking position. The bolting member


33


also provides an abutment shoulder


34


. At the inner or forward end of the bolt there are provided in an edge


35


of the main portion a ratchet retaining means including a first and a second recess


36


and


37


separated by a smoothly curved ridge


38


, and a positive retaining means comprising a shoulder


39


being substantially perpendicular to the edge


35


.




In order to guide movement of the holding bolt and to yieldably retain it in its unlocking and locking positions, there is provided a guide and ratchet member shown separately in FIG.


5


. This member is an integral structure, preferably made of a synthetic resin, including a stationary portion


40


and a movable leg portion


41


joined to the stationary portion by a resilient portion


42


. Portion


40


is kept stationary relative to the lock case by means of opposed circular bosses


43


fitting in corresponding bores


44


,


44


′ in the lock case walls


2


and


3


, respectively, and likewise opposed protrusions


45


fitting in the L-shaped apertures


28


,


28


′, respectively. A guide opening


46


extends through the protrusions


45


and the stationary portion


40


so as to smoothly guide lengthwise movement of the holding bolt. The guide opening has an L-shape conforming to the cross section of the foremost end of the holding bolt, i.e., its longer leg


31


and shorter leg


32


, such that the abutment shoulder


34


restricts movement of the holding bolt in a forward direction by abutting an abutment surface


47


of the stationary portion


40


, thus defining the bolting position of the holding bolt.




In order to yieldably retain the holding bolt in its unlocking position and its locking position, there is provided a retaining means in the shape of a helical spring


48


(

FIG. 3

) having its coil


49


positioned about a cylindrical post


50


provided on the moveable portion


41


. The spring


48


has a first substantially straight end portion


51


bearing on a wall


52


of a substantially horizontal slot


53


in the leg portion


41


. A second substantially straight end portion


54


of the spring extends through a substantially vertical slot


55


(

FIGS. 3 and 5

) through the leg portion


41


and bears on an inner wall


56


thereof.




As appears from

FIG. 3

, the screw


11


abuts the free end


41


′ of the leg portion


41


, thus restricting possible movement thereof to the left of FIG.


3


. In this position, the resilient portion


42


of the guide and ratchet member, in its relaxed state having a moderately curved shape as shown in

FIG. 5

, adopts a more sharp bend substantially conforming to the inner corner between case walls


4


and


7


. In this position, the leg portion


54


extends through the cross section of the guide opening


46


. Now, when inserting the holding bolt


27


in the guide opening


46


, a bevelled corner


30


′ (

FIG. 6

) of its guide portion


30


encounters the straight end portion


54


of spring


48


and, upon further insertion, presses it to the left until it comes to rest against the edge


35


and slide therealong until it snaps into the foremost recess


36


. In this position, which is the unlocking position, withdrawal of the holding bolt is prevented by the shoulder


38


abutting the spring end portion


54


. This, in turn, is supported by the walls of the slot


55


so as not to flex in the direction of withdrawal. However, further insertion of the holding bolt is possible due to the smoothly curved ridge


38


forcing the spring end portion


54


to yield outwardly and then snap into the second recess


37


. In this position, which is the locking position of the holding bolt, the abutment shoulder


34


contacts the abutment surface


47


provided on the stationary portion


40


of the guide and ratchet member and prevents further insertion into the lock case.




The lock according to the present invention is primarily intended to be delivered to customers without the holding bolt mounted. As appears from the drawings, there are provided in each half


1




a,




1




b


of the lock case two L-shaped apertures


28


,


28


′ and two bores


44


,


44


′. This enables the lock to be factory mounted with two guide and ratchet members. If, on the other hand, the lock is delivered with merely one guide and ratchet member as shown, the customer may shift the position of the guide and ratchet member at will.




Once the lock has been inserted into a corresponding recess in a door leaf and fastened to an edge thereof by means of screws through the holes


9


,


10


, and then the holding bolt has been inserted into the lock as described above, the holding bolt can no longer be retracted beyond the unlocking position, and, consequently, the lock cannot be removed from the door.




In order to enable retraction of the holding bolt, and, thus, to enable removal of the lock, the present invention provides for withdrawal of the spring end portion


54


such that it no longer passes the cross section of the aperture


46


. This has been achieved by the provision of the movable leg portion


41


of the guide and ratchet member carrying the spring


48


and by its support against the end of screw


11


. By simply unthreading the screw


11


as shown in

FIG. 4

, the movable leg portion carrying the coil


49


of spring


48


will be caused by the spring force of the resilient portion


42


adjoining the movable portion and the stationary portion of the guide and ratchet member to move to the left in FIG.


3


. At the end of such movement, the end


41


′ of the movable portion may come to rest against the inner side of case wall


6


as shown in FIG.


4


. In any case, and as likewise shown, the spring end portion


54


has left the cross section of the aperture


28


which, thus, is open for withdrawal of the holding bolt. After wihdrawal of the holding bolt and removal of the lock from its location in a door leaf, the screw


11


may be screwed in again to make the lock ready for renewed mounting, possibly with the holding bolt inserted through an alternate aperture


28


.



Claims
  • 1. A lock comprising:a lock case; a forend attached to said lock case by at least one fastening member being removable in an axial direction thereof; a latch bolt movable within said lock case between a locking position, in which it projects at least partly from said case, and an unlocking position, in which it is retracted within said lock case; a holding bolt being positionable in a first, relatively retracted position allowing movement of said latch bolt from its locking position to its unlocking position, and in a second relatively inserted position preventing movement of said holding bolt from its locking position to its unlocking position; and spring means for yieldably retaining said holding bolt in its first and second positions and for positively preventing withdrawal thereof form said lock case; said fastening member is operatively connected to said spring means so that upon at least partial removal of said fastening member in said axial direction at least one portion of said spring means shifts from a first position, defining an abutment means where said holding bolt abuts abut said at least one portion to prevent withdrawal of said holding bolt, to a second position, in which said holding bolt is free for withdrawal from said lock case.
  • 2. The lock according to claim 1, wherein said lock case accommodates a stationary guide member having a guide aperture for guiding movement of said holding bolt, said at least one portion of said spring means extending across at least a portion of said aperture in said first position of said spring means and leaving said aperture free in said second position.
  • 3. The lock according to claim 2, wherein said spring means is carried by a movable member operatively connected to said at least one fastening member.
  • 4. The lock according to claim 3, wherein said fastening member acts on a portion of said movable member facing said fastening member.
  • 5. The lock according to claim 2, wherein said spring means is a helical spring having a coil portion and first and second substantially straight end portions, said coil portion being carried by said movable member, and one of said first and second end portions extending across said guide aperture to positively engage said holding bolt in said first position of said spring means.
  • 6. The lock according to claim 3, wherein said stationary guide member is integral with said moveable member.
  • 7. The lock according to claim 6, wherein said movable member is joined to said stationary member by a resilient portion.
  • 8. The lock according to claim 2, wherein said stationary guide member is provided with protrusions fitting into corresponding apertures in said lock case.
  • 9. The lock according to claim 1, wherein said fastening member is a screw.
  • 10. The lock according to claim 2, wherein said guide aperture is L-shaped and said holding bolt at least partially has an L-shaped cross-section matching said L-shape aperture.
US Referenced Citations (9)
Number Name Date Kind
2295435 Teich Sep 1942
2727773 Hagstrom Nov 1955
4143529 Brummett Mar 1979
4296956 Colombo Oct 1981
4297862 Solovieff Nov 1981
4974883 Jans Dec 1990
5141268 Keller Aug 1992
5474348 Palmer Dec 1995
5779287 Johansson Jul 1998
Foreign Referenced Citations (1)
Number Date Country
0364781 A2 Apr 1990 EP