Technical Field

The present invention relates to a cylinder-lock attachment means , sometimes referred to as a cylinder- lock fitting, of the kind comprising an escutcheon or the like; a cylinder lock; one or more headed screws for securing the cylinder lock; and a hole for respective screws , said hole having a widened portion in which the screw head of respective screws is seared.

Background Art

Previously known cylinder-lock attachment means of this kind are normally designed to be mounted on the inside of a door, and to this end are designed to fit into a standard-size hole made in the door for this pur¬ pose, the diameter of the hole in the case of Swedish standards being ^u 0mm.

The headed screws are passed through the cylinder lock and are normally screwed into a corresponding cylinder lock on the outside of the door, in which case ^' the screws are passed through a lock housing arranged in a recess in the door and accommodating a lock mechanism normally a latch plunger mechanism - which can be acti- vatεd by the cylinder locks.

^• The escutcheons or cylinder fittings may also be mutually connected together by means of one or more screws , which then also pass through the lock housing.

Thus, the cylinder lock located on the outside of the door is joined to the cylinder lock on the inside of the door by means of screws whose heads are located in the "inner" lock and which cannot therefore be reached from the outside of the door. The screw-heads, however, can be reached from the inside of the door, and tightening of the screws with a screw driver causes the two cylinder

locks to be urged towards each other while being accurately fixed and aligned relative to each other and to ^' the door.

An arrangement of this kind creates problems when the door in question cannot be considered to have an inside and an outside, i.e. both sides of the door can be considered as the "outside". This is primarily the case with locales and rooms which have additional entrance possibilities. In this case it is relatively simple for a person to unlawfully acti¬ vate the "inner" cylinder lock, by simply unscrewing the readily accessible screws, removing the cylinder lock and then releasing the latch plunger mechanism, in the lock housing, in a suitable manner. Normal houses and flats present a similar problem, particularly if an intruder is able to gain entrance through a readily forced balcony door, a lower floor window or the like, whereafter the cylin¬ der lock on the "inside" of a door can readilv- be opened in the aforesaid manner, enabling the intruder to leave through a conventional exit , normally the main front door, together with any goods stolen. It will readily be understood that much less attention will be paid to ^~ .n intruder who uses a normal exit as his retreat path, and that he or she will be more difficult to discover than if leaving the building, together with any goods stolen, via a lower floor window, balcony door or the like.

Disclosure of the Invention

It will be obvious from the aforegoing that there is a need firstly to render all screws in an "inne " cylinder lock inaccessible, and secondly to reinforce the attachment-fitting

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arrangement, including both the inner and outer _, escutcheons as a whole, so as to increase the re¬ sistance against the use of force.

Those methods previously proposed for hiding or covering both the inside and outside of the screws joining the locking cylinders and escutcheons respectively in a cylinder-lock fitting arrangement of the kind meant here have not been satisf ctory. Thus , only ^' a small amount of force has been needed to render the heads of the screws accessible. Further¬ more, it has been relatively simple to remove the attachment fittings with the aid of a crowbar or like forcing implement, and then to activate the locking mechanism in the lock housing in a manner to enable the door to be opened.

Accordingly- an object of the present invention is to provide an attachment-fitting arrangement in which the heads of the screws which anchor the cylinder lock or locks are practically inaccessible to unautho- rized persons, but readily accessible to authorized ^' persons possessing a key to the cylinder lock in question.

Another object of the invention is to provide an attachment-fitting arrangement which comprises escutcheons which are joined to one another by means of screws and which are accommodated in a hole of standard size on both sides of the door and which have an improved strength and resistεncε to force. Still another object of the invention is to provide an attachment- itting arrangement of the aforementioned kind which can be used on either the inside or the outside of a door, depending upon the security requirments required against forced entry.

Brief Descriotion of the Invention

An attachment-fitting arrangement according to the present invention is mainly characterized by a screw-head latching or plugging element anchored in the cylinder lock, said latching or plugging ele- ment being removable, so that the heads of the screws will not be accessible for loosening until the plug of the cylinder lock is rotated to a predetermined position of rotation by means of a key belonging to the lock. The latching element renders the screw heads inaccessible and/or prevents the screws from being undone, and hence it is of no matter on which side of a door the cylinder lock in question is located. An intruder who has unlawfully entered a room pro- vided with a door having fitted to the inside there¬ of a cylinder lock of the kind in question will be unable to reach the heads of the screws anchoring the cylinder lock, since he is prevented from doing so by means of said latching element. On the other hand, it is a simple matter for an authorized person possess¬ ing a key to the cylinder lock to insert the key into the lock and turn s-aid lock to a predetermined angular position, whereafter the latching element can readily be removed so as to expose the heads of the cylinder- lock anchoring screws.

According to one suitable embodiment of the invention a sealing means for anchoring the latching element in said predetermined position of the C2/Iinder plug can be moved to a release position in which the latching element can be withdrawn through said widened part of said hole.

Such a sealing element may have comparatively small and slender dimensions and still afford pur¬ poseful and reliable anchoring of the latching element In this respect, in practice the sealing element

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preferably has the form of a pin movably arranged in a bore which extends at right angles to the axis of the widened part of said hole and which, in said predetermined position of rotation of the cylinder plug, coincides with a radially extending, peri¬ pheral hole in the cylinder plug, in which hole part of the sealing pin is able to enter against the action of a spring when a force is exerted on the sealing element for withdrawing ^" the same. It will be understood that despite its simplicity the sealing pin constitutes a reliable element for anchoring the latching element, said anchorage being effected by passing the pin into a recess, for example into a waisted portion of the latching element. ^• When the latching element is withdrawn, the sealing pin will be urged inwardly against the action of said spring, towards the centre of the cylinder plug at the same time as the latching element is withdrawn. To facilitate co-action between the two

^■ elements ,the sealing pin suitably has a rounded end, while the recess, for example the waisted portion of the latching element, has a concave ^' shape.

Further, the latching element suitably has at its outer end a weakened grip portion, e.g. of - frusto-conical configuration, arranged to fracture if force is used there against when attempting to withdraw the latching element.

In a previously known attachment-fitting arrangement of the kind mentioned in the introduction, although lacking both the latching element and the sealing means therefor - there is provided in the cylinder fitting outside the cylinder lock one or more holes and a corresponding number of headed screws which are inserted through said holes and by means of-

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which the cylinder fitting can be connected to a further cylinder fitting on the other side of a door or the like on which the cylinder fitting is mounted. In the end of the cylinder fitting there is an internal screw thread arranged to cooperate with a corresponding screw thread on the periphery of an end plate arranged to cover said screw heads when said plate is screwed into the cylinder fitting, and with a hole which registered with the plug of the cylinder lock, so as to leave the key slot of the plug accessible.

One embodiment of an attachment-fitting arrange¬ ment according to the invention is of this kind and is characterized by one or more holes arranged in the end plate in register with the widened, hole portions in the cylinder lock accommodating the latching ele¬ ment or elements, said latching element or .elements being passed through said holes in the end plate so as to lock said end plate against rotation. Thus, the relatively simple latching element which renders the anchoring screws of the cylinder lock inaccessible obtains the further function of preventing rotation of the end plate ^' or catch plate, which in turn also renders inaccessible the screw heads -located behind the said end plate of the screws which connect the escutcheon of the attachment- fitting arrangement to a corresponding escutcheon on the other side of the door, since the catch plate or end plate cannot be removed. According to a modified embodiment, the latching element is accommodated in a special hole in the cylinder lock and is provided with .a head member which engages directly, or indirectly via a cover plate, -.;o mutually adjacent screw heads, so as to prevent the screws being loosened. In this instance, the actual

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cylinder lock is preferably of circular-cylindrical shape. For aesthetic reasons the cylinder lock may be enclosed in a cover member which covers the screw heads and the latching element, and which has a .hole for receiving the plug of the cylinder lock. The hole- may be surrounded by a fitting or a plate having a more decorative purpose, i.e. not needing to be permanently anchored.

3rief Description of the Drawings

Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings .

Figure 1 is a perspective view of a first embodiment of a cylinder lock fitting connected to a similar cylinder lock fitting by means of four screws .

Figure 2 is a similar perspective view showing the two lock fittings illustrated in Figure 1 as seen from the other side.

Figure 3 is a partially cut-away end view of a cylinder lock arranged to be accommodated in a cylinder lock fitting according to Figure 1 and pro¬ vided with a latching and sealing arrangement accord- ing to the invention.

Figure 1 is a partially cut-away side view of the cylinder lock shown in Figure 3 , together with associated latching element and sealing pin.

Figure 5 is a perspective view of two mutually connected cylinder lock fittings according to Figure 1, subsequent to mounting the associated cylinder lock and latching element.

Figure 6 is a sectional view of the cylinder lock fitting arrangement shown in Figure 5 , taken on the line VI-VI .

Figure 7 is a perspective view of a modified attachment-fitting arrangement, in which the two cylinder locks are of circular-cylindrical configura¬ tion, and the latching element is arranged in a separate hole between two screw holes.

Figure 8 is a sectional view taken on the line VIII-VIII in Figure 7.

Figure 9 is a partially cut-away front view of the cylinder lock arrangement illustrated in Figure 7.

Figure 10 is a sectional view corresponding to part of Figure 8 , of a further embodiment in which a latching element engages two mutually ad¬ jacent screw heads via a separate cover plate. Figure 11 is a perspective view of a cylinder- lock arrangement shown in Figure 7 or Figure 10 mounted onto a door, in which the cylinder lock is surrounded by a cover and an external plate attached to the door. ' ^•

^' Description of Preferred Embodiments

With reference to Figures 1 and 2 there is shown an attachment fitting for a cylinder lock, said attachment fitting comprising a so-called cylinder lock fitting 1 having an escutcheon 2 having a male part 2d arranged to be housed in a -Omm hole, -and an end plate or catch plate 17 having a peripheral screw thread which co-acts with corresponding screw threads on the escutcheon 2 , enabling said plate to be screwed thereinto. The end plate or catch plate 17 is provided with a circular hole 17a, which pro¬ vides access to the key slot of a cylinder lock (not shown in Figs. 1 and 2) arranged in the lock fitting The catch plate also has two holes 17b, which are excentrically located relative to the axis of said

catch plate and the purpose and function of which will be described in more detail hereinafter.

As will be seen from Figure 2 , the escutcheon 2 and the male part 2d are also provided with a recess 2a for accommodating a cylinder lock.

The lock fitting 1 is connected by means of four robust screws 15 to an oppositely located lock fitting 1' , which is of similar design to the lock fitting 1. Thus, the lock fitting 1' comprises an escutcheon 2' having a male part 2'd, a recess 2 'a for a cylinder lock, and a catch plate or end plate 17 ' having a round hole 17 'a co-responding to the position of the key slot for the plug of a cylinder lock. The end plate 17' of the lock fitting 1', however, lacks excεntrically located holes corres¬ ponding to the hole 17b of the end plate or catch plate 17 of the lock fitting 1.

The four screws 16 connecting the escutcheons 2 and 2 ' of the two lock fittings together provide a considerable rein orcement in relation to con¬ ventional arrangements .

Figures 3 and 4 illustrate a cylindrical lock 3 intended to be accommodated in th escutcheon 2 of the lock fitting 1 shown to. the left of Figure

1.

The cylinder lock 3 is partially of conven¬ tional design and is provided with a rotatable plug 3a having a key slot 3b. Above the plug 3a are two holes 5 for anchoring screws 4 provided with heads -a. , said heads being accommodated in a widened forward hole-part 5a of the holes 5 , so that said heads 4a seat in the widened hole parts .

The anchoring screws 4 ' are screwed, in a nor- al way, into screw-threaded holes of an oppositely

situated cylinder lock 3 ' accommodated in the es¬ cutcheon 2' (not shown in Figures 1 - 4) of the other cylinder fitting 1".

In order to make the screw heads 4a inaccessible, -. there is arranged in the widened hole part 5a, in front of the screw heads , a latching element 5 in the form of a cylindrical body having a centrally located recess in the form of a waisted portion 6a. The latching element 6 is arranged for rotation in the hole part 5a and is adapted to co-act with a sealing means in the form of a pin or peg 7 movably arranged in a bore 8 and extending at right angles to the axis of the hole part 5a.

In the position occupied by the plug 3a in Figure 3 - which position can only be reached by in¬ serting the correct key into the key recess 3b and turning the core to said position - the bore 3 is in register with a hole 9 arranged peripherally of the plug, in which hole there is provided a spring 10 and a surround- ing sleeve 11. Thus, the sealing pin 7 can be urged in this position inwardly towards the axis of the plug, against the action of the spring 10 , permitting the latching element 6 to be withdrawn from the hole part 5a. Consequently, the latching element 5 can only be removed by using the correct key and rotating the plug to the position shown in Figure 3.

As will be seen from Figure 3 , a further latching element 6 and associated sealing pin 7 is provided at the other side of the cylinder lock, and hence the plug must be rotated further in the other direction before this additional latching element can be removed.

In the embodiment illustrated in Figures 3 and 4, the end 7a of the sealing pin 7 co-acting with the waisted portion 5a is curved or bent, and consequently,

when the plug is located in its correct position, the sealing pin will automatically be pressed in when the latching element 6 is withdrawn. In prac¬ tice, the latching element 6 is withdrawn by grasping the frusto-conical peg 6b located on the outer end of the latching element, with a pair of pliers oi: lit like. The conical peg δb is arranged to fracture if excessive force is exerted thereonto. Thus, if an attempt is made to withdraw the latching element by grasping the peg δb with a pair of pliers , without moving the plug to the position shown in Figures 3 and 4, the peg 6b will fracture, causing even greater difficulty in removing the latching element by force. The construction of the two cylinder fittings 1 and 1' in connection with a lock housing 22 mounted in position on a door (not shown) is illustrated in Figures 5 and 6. Figure 5 illustrates the two frusto- conical ends 6b of latching element 6 , subsequent to mounting said elements 5 in position in the left-hand cylinder fitting 1' and sealing or fixing the position of said elements by means of said sealing elements, the plug 3a being subsequently rotated to the position in which the key can be removed. The two cylinder locks 3 and 3 ' are then anchored together by means of screws 4, the heads of which (not shown in Figures 5 and 6) are inaccessible as a result of the sealed latching elements , the ends 6b of which are shown in the two figures.

The escutcheons 2 , 2 ' of the cylinder fittings 1, 1' are shown joined together by means of four screws 16 , the heads 16a of which are accommodated in the space 2b in the left-hand escutcheon 2 , inwardly of the catch plate or end plate 17. In the Figure 5 embodiment, one screw head Iδa of two mutually adjacent screws 16 passes through a spacer plate 13, preventing

the screw heads from interfering with one another.

Inwardly of the catchplate 17 , which has peripheral screw-threads 17c and is screwed into an ^' internal screw-thread 2c in the escutcheon 2 , there is arranged a perforated support plate 20 for receiving the latching elements 5 and the plug 3a of the cylinder lock 3. Support plate 20 of vary¬ ing thicknesses can be arranged in position in¬ dependence on the type of cylinder lock used. The right-hand escutcheon 2 ' is also provided with a screw-in end plate 17 ' , which lacks recesses for latching elements, however, Cc.f.2).

Subsequent to placing the cylinder fittings in position, the screws < and 16 are tightened, whereafter the support plate 20 is inserted into the recess 2b and the end plate 17 is screwed in until it is contigous with the support plate 20. It should be seen at the same time that the two recesses 17b (c.f. 1) accommodating the latching element 6 are in register with a respective widened hole-part 5a in' the cylinder lock 3 (c.f.O.

The correct key is then inserted into the cylinder lock, and the plug 3a of the lock ro¬ tated until the bore 8 (Figure 3) and the peripherial hole 10 are in register with one another. The latching element 6 is then pressed in, 'which is made possible by inward movement of the sealing pin 7 in the hole , against the action of the spring 10. The cylinder plug is then rotated in the other direction, whereafter the operation is repeated with the other larfhing element 5. hen the plug of the cylinder lock is then rotated, so that the key recess takes a vertical position and the key is removed, the screw heads of the cylinder lock are latched and sealed so as to be inaccessible. At the

same time, the outwardly projecting ends 5b of the sealing pins -6 prevent rotation of the catch plate or end plate, which prevents said plate from being removed from the escutcheon 2. Consequently, the heads 16a of the four screws 16 joining the escut¬ cheons 2 and 2' are also inaccessible.

Figures 7 - 9 illustrate a modified embodi¬ ment in which two circular-cylindrical cylinder locks 3, 3' arranged on both sides of a door (not shown) are joined together by means of four screws 4.

In this embodiment , the latching element 6 is not accommodated in the same widened hole part 5a as the screw heads 4a. Instead, there is pro- vided between two such widened hole parts 5a a separate hole 12 for receiving the latching ele¬ ment 6 ^" , which, in the illustrated embodiment, in addition to having a waisted portion 6a for co- action with a sealing pin 7 , also has a forward head δc which carries a frusto-conical peg 5b. In this embodiment , the element 6 can suitably be called a catch, since the head 6c is intended to engage two mutually adjacent screw heads 4a in a manner to prevent the screws 4 from being removed even though the heads can be reached with a spanner or some other tool, provided that that element 6 is in position.

In the embodiment illustrated in Figure 10 , the head δc of the latching element or catch δ engages the heads 4a of two mutually adjacent screws via a separate plate 13 , which prevents the heads being reached with a screwdriver or like tool.

It will be seen from Figure 9 that the .latch- ing element 6 co-acts with a sealing pin 7 in a

manner similar to the previously described embodi¬ ments.

In the embodiment illustrated in Figure 11, the cylinder lock, when mounted onto a door, is e - braced by a cover 20 having a mainly decorative purpose, i.e. is not intended to increase the reli¬ ability of the arrangement against forced entry. The cover, however, covers the screw heads 4a and the latching or plugging elements 6 , and is provided with a hole for receiving the cylinder plug 3a. The cylinder lock and cover may also be surrounded by an escutcheon 2 , which is mounted on the door and, unlike the escutcheons 2 referred to in connection with the embodiment irst-described, need not necessarily be connected to a corresponding escutcheon, but may be fastened to the door in a conventional manner. The screws 4 connecting the two cylinder locks located on respective sides of the door, together with the plugging or latching element which hides ^* the screw heads and prevents them from being turned to unscrew the screws, are sufficient to render the entire lock arrangement safe against forced entry.

Industr≤L Applicability

As will be readily understood by those skilled in this art, the basic concept of the inven¬ tion of anchoring a plugging or latching element by means of a sealing pin radially movable relative to the plug of the cylinder lock, so that the plugging o -latching element can only be removed by persons possessing a key which fits the cylinder lock, can also be used in other connections , where it is de¬ sired to strengthen the attachment of a cylinder lock in a manner which makes forced entry more diffi-

cult. It has been shown above that the actual cylinder lock may have different forms >and designs, and that the form of the escutcheon or lock fitting can also vary. Thus, the robust fitting 1 with the integrated escutcheon 2 of the embodiment first- described has been replaced in the embodiment accord¬ ing to Figures 7 - 11 with a thin cover 20 and separate escutcheon 2. It is also possible instead to form part of the actual cylinder lock 3 as a lock fitting or escutcheon. Further, it is not necessary to connect together two cylinder locks located on a respective side of a door. When only one cylinder lock is used, the cylinder lock can be made inaccessible by fitting and anchoring the same while applying the basic idea of the invention.