An electric door lock unit comprising a four-bar linkage

Abstract

The invention relates to an electric door lock unit (1) for installation in a door leaf (100) to interact with a strike plate (120) of a door frame (110), the door lock unit (1) comprising - a latch (10),- an interlock member (20) that is movable between a block position (20b), in which the latch (10) is blocked from movement, and a release position (20r), in which the latch (10) is not blocked from movement,- an electric actuator (30), and- a transmission assembly operatively arranged between the electric actuator (30) and the interlock member (20),wherein the transmission assembly comprises a four-bar linkage (40).

Description

The present Swedish patent application is filed concurrently with the following related Swedish patent applications by the same applicant. The features of these patent applications are to be considered incorporated by reference into each other. The related patent applications, including the present one, are titled:An electric door lock unit comprising a reversible dual-bevel latchAn electric door lock unit comprising a four-bar linkageAn electric door lock unit with switchable power-to-open and power-to-lock function A door lock unit configured to block a latch when a bolt is extendedTECHNICAL FIELDThe present invention generally pertains to door lock units, and more precisely to an electric door lock unit that comprises a four-bar linkage. The electric door lock unit may typically be adapted for installation in a door leaf.BACKGROUNDDoor lock units have a vast range of applications, such as at hotels, hospitals, offices, or the like. For certain applications, electric door lock units, for example solenoid or motor locks, are particularly popular. A common type of electric door lock units is activated, e.g. locked or unlocked, by means of a magnetic card, a mobile phone, an RFID tag, a security system, or the like. In other applications, the door lock unit may be operated manually, i.e. without a solenoid or the like.Even though today’s door lock units generally function satisfactorily, there is still room for improvement in terms of security, durability, ease of installation, and cost.SUMMARYA general object of the invention is to address the challenges mentioned above. In particular, an object is to ensure that the lock is highly secure, tamper-proof and reliable. Preferably, the invention of the present disclosure is to provide a mechanical mechanism that is compact, robust, and easy to manufacture and assemble. Compact mechanical mechanisms are particularly beneficial in modern electric door units, where space is required for electric and electronic equipment.In accordance with the present disclosure, there is provided an electric door lock unit for installation in a door leaf to interact with a strike plate of a door frame. The door lock unit comprises a latch, an interlock member that is movable between a block position, in which the latch is blocked from movement, and a release position, in which the latch is not blocked from movement. There is further an electric actuator and a transmission assembly operatively arranged between the electric actuator and the interlock member. The transmission assembly comprises a four-bar linkage.It has rather surprisingly been recognised by the inventor that the four-bar linkage offers significant advantages as regards the operation of the electric door lock unit. For example, the movement of the electric actuator reliably operates the latch, even if a relatively low-powered electric actuator is used. Thus, the present disclosure allows for a relatively low-cost electric actuator to be employed. It is believed that, possibly, the mutual relative movement of the components of the four-bar linkage may contribute to the reliable movement of the latch. Said movement may possibly involve a kinetic energy that contributes to the reliable latch movement. Another advantage is that the four-bar linkage allows for relatively flexible positioning of the electric actuator in relation to the latch, which is beneficial particularly since there is limited space available in the electric door lock unit.Further advantages and advantageous features of the invention are disclosed in the following description and in the dependent claims.DESCRIPTION OF THE DRAWINGSBelow embodiments of the invention will be described with reference to the drawings, in whichfigure 1 shows an electric door lock unit with an emphasis on a four-bar linkage thereof,figures 2 to 7 illustrate the operation of the electric door lock unit of figure 1, and in particular the operation of the four-bar linkage,figure 8 is a detailed view of the four-bar linkage of the previous figures inisolation,figure 9 is a detailed view of the electric door lock unit,figures 10 and 11 show the electric door lock unit of figures 1 to 7 and 9 in two perspective views, andfigures 12 and 13 illustrate a door frame for a door leaf in which the electric door lock unit may be installed.DETAILED DESCRIPTION OF EMBODIMENTSFigure 1 shows an electric door lock unit 1 suitable for installation in a door leaf 100 to interact with a strike plate 120 of a door frame 110. Referring also to figures 2 to 9, the electric door lock unit 1 comprises a latch 10 and an interlock member 20. The latter is movable between a block position 20b, in which the latch 10 is blocked from movement, and a release position 20r, in which the latch 10 is not blocked from movement.The electric door lock unit 1, or lock unit, further comprises an electric actuator 30, in the present example in the form of a solenoid. Moreover, lock unit 1 comprises a transmission assembly operatively arranged between the electric actuator 30 and the interlock member 20. Thereby, the transmission assembly is configured to influence the operation, or operate, the interlock member 20 by means of an input from the electric actuator 30. As is shown, see in particular figures 1, 3 and 5 to 8 the transmission assembly comprises a four-bar linkage 40.As is illustrated, the interlock member 20 and the electric actuator 30 may be positioned on opposite sides of the latch 10 within a casing 5 (denoted in figure 10) of the electric door lock unit 1, with the four-bar linkage 40 extending between the electric actuator 30 and the interlock member 20. Thus, the four-bar linkage 40 may be elongated to allow for a spatial separation between the interlock member 20 and the electric actuator 30 in the electric door lock unit 1. The four-bar linkage 40 may suitably designed to allow for a desired disposition of the interlock member 20 and the electric actuator 30 in the electric door lock unit 1.Referring in particular to figure 9, in use, the interlock member 20 may be disposed in an upper half of the electric door lock unit 1, and the electric actuator 30 is primarily disposed in the lower half of the electric door lock unit 1 , or vice versa. In use, the lock unit 1 is typically oriented as shown e.g. in figures 9 to 12. There may be a lower hub, or latch hub, that is rotationally journaled in the lock unit 1 and arranged to move the latch 10, the latch hub optionally being connected to a door handle (figures 12 or 13) or a doorknob. Further, there may be an upper hub, or bolt hub, that is rotationally journaled in the lock unit and arranged to move the latch 20, the bolt hub optionally being connected to e.g. an undepicted emergency handle, an undepicted electric actuator, or an undepicted a key cylinder.Referring e.g. to figures 6 to 8, the interlock member 20 and the four-bar linkage 40 may be interconnected by a pin-and-slot joint 43p, 20s. The slot 20s of the pin-and-slot joint 43p, 20s may be shaped to prevent the interlock member 20 from moving between the block position 20b and the release position 20r in response to the electric door lock unit 1 being subjected to an impact.The slot 20s of the pin-and-slot joint 43p, 20s may as shown comprise a stop section 20ss that extends substantially transverse to the movement direction of the interlock member 20 from the block position 20b to the release position 20r. Thereby, it may be prevented that the interlock member 20 may move between the block position 20b and the release position 20r in response to the electric door lock unit 1 being subjected to an impact.Importantly, it is put forward that the herein described a pin-and-slot joint, shaped to prevent an interlock member from moving between a block position and a release position in response to an electric door lock unit being subjected to an impact, may be apphed to lock units of other designs. For example, such a pin-and-slot joint may be applied to lock units that lack a four-bar linkage. Herein, the door lock unit is exemplified as a mortise lock (or mortise lock), as shown.As is shown, the four-bar linkage 40 may comprises an input link 41, a coupler link 42, an output link 43 and fixed link 44. As indicated in figures 3 and 5, the fixed link 44 may be formed by a stationary part such as the casing 5. The input link 41 and the output link 43 are rotatably journalled to the casing.The output link 43 may comprise either the pin 43p or the slot 20s of the pin-and-slot joint 43p, 20s, and the interlock member 20 may comprise the other of the pin or the slot of the pin-and-slot joint. In the present example, the output link 43 comprises pin the 43p of the pinand-slot joint, and the interlock member 20 comprises the slot 20s of the pin-and-slot joint.As is shown, the electric actuator 30 may be connected to the input link 41 and the interlock member 20 is connected to the output link 43. In the present example, the coupler link 42 connects the input link 41 to the output link 43, the input link 41 is an input rocker arm and the output link 43 is an output rocker arm.Referring in particular to figure 5, the four-bar linkage 40 may be configured such that the coupler link 42 undergoes a combined translatory and rotatory motion when the four-bar linkage 40 is actuated by the electric actuator 30. Possibly, the kinetic energy of the moving coupler link 42 is beneficial for the reliable movement of the latch. The lock unit 1 may be designed such that the force required to move the interlock member 20 from the block position 20b to the release position 20r exceeds the force output of the electric actuator 30. A lever arm obtained by the four-bar linkage 40, and possibly the mentioned kinetic energy, may enable the movement of the interlock member 20.Referring to figures 2, 4, 6, 7 and 9, the lock unit 1 may comprise a biasing member 25 arranged to bias the interlock member 20 towards the block position 20b. There may further be an auxiliary latch 50 arranged to interact with the strike plate 120 between an engaged state 50e, in which the interlock member 20 is blocked from movement, and a disengaged state 50d, in which the interlock member 20 is not blocked from movement. The electric actuator 30 may be arranged to move the interlock member 20 from the block position 20b to the release position 20r. Generally, also in lock units of other designs, e.g. not comprising an auxiliary latch, the electric actuator 30 may be arranged to move an interlock member from a block position to a release position.The four-bar linkage 40 may comprise four pivot joints P1-P4 as denoted in figure 3. The input link 41, or input rocker or input driver, may be rotationally journalled in the lock unit 1 via a first pivot joint P1. The input link 41 may be connected to the coupler link 42, or connecting link or floating link, via a second pivot joint P2. The coupler link 42 may be connected to the output link 43, or output rocker, via a third pivot joint P3. The output link 43 may be rotationally journalled in the lock unit 1 via a fourth pivot joint P4. All movements of the four-bar linkage may occur in-plane A with the lock unit 1. The four-bar linkage may be referred to as a four-joint linkage.It is to be understood that the embodiments described above and shown in the drawings are non- limiting examples of the invention, and that the latter may be modified in many ways within the scope of the appended claims.However, except for the schematic figures 12 and 13, the drawings do disclose a possible actual implementation and should not be regarded as simply serving to give a schematic explanation of the principles of the subject-matter of the invention.Not all components of the electric door unit, shown in particular in figures 1 and 9, are described herein. Still, a skilled person will be able to clearly and unmistakable recognise from the drawings how these components are designed and cooperate. Furthermore, the shapes and lever arms of the four-bar linkage 40 are not described in full detail herein, and additional features defining their shapes and at least relative dimensions may be derived from in particular figures 3, 5 to 9. For example, it is clearly shown where biasing elements in the form of springs may be arranged, and that the interlock member 20 comprises a block surface or hook feature arranged to bear against the latch 10 to block the latter in its extended position.

Claims

1. Electric door lock unit (1) for installation in a door leaf (100) for cooperation with a strike plate (120) of a door frame (110), wherein the door lock unit (1) comprises- a fall piston (10),- a locking member (20) movable between a blocking position (20b), in which the fall piston (10) is blocked from movement, and a release position (20r), in which the fall piston (10) is not blocked from movement,- an electric actuator (30), and- a transmission device operatively arranged between the electric actuator (30) and the locking member (20),wherein the transmission device comprises a four-link mechanism (40) comprising an input link (41), a coupling link (42), an output link (43) and a fixed link (44), wherein the electric actuator (30) is connected to the input link (41) and the locking member (20) is connected to the output link (43), and wherein the four-link mechanism (40) is configured such that the coupling link (42) undergoes a combined translational and rotational movement when the four-link mechanism (40) is actuated by the electric actuator (30).

2. Electric door lock unit (1) according to claim 1, wherein the latching member (20) and the electric actuator (30) are located on opposite sides of the latching piston (10) within a housing (5) of the electric door lock unit (1), and the four-link mechanism (40) extends between the electric actuator (30) and the latching member (20).

3. An electric door lock unit (1) according to claim 1 or 2, wherein the four-link mechanism (40) is elongated to enable spatial separation between the latching member (20) and the electric actuator (30) in the electric door lock unit (1).

4. An electric door lock unit (1) according to claim 2 or 3, wherein the locking member (20), in use, is arranged either in an upper half or in a lower half of the electric door lock unit (1), and wherein the electric actuator (30) is arranged mainly in the other half of the electric door lock unit (1).

5. An electric door lock assembly (1) according to any preceding claim, wherein the latch member (20) and the four-link mechanism (40) are interconnected by a pin and groove joint (43p, 20s).

6. Electric door lock unit (1) according to claim 5, wherein the groove (20s) of the pin and groove joint (43p, 20s) is designed to prevent the locking member (20) from moving between the blocking position (20b) and the releasing position (20r) as a result of the electric door lock unit (1) being subjected to an impact, said groove (20s) comprising a stop section (20ss) extending substantially transversely to the direction of movement of the locking member (20) from the blocking position (20b) to the releasing position (20r), to prevent the locking member (20) from moving between the blocking position (20b) and the releasing position (20r) as a result of the electric door lock unit (1) being subjected to an impact.

7. An electric door lock assembly (1) according to claim 5 and any preceding claim, wherein the output link (43) comprises either the pin (43p) or the groove (20s) of the pin and groove joint (43p, 20s), and wherein the latching member (20) comprises the other of the pin or the groove of the pin and groove joint.

8. An electric door lock assembly (1) according to any preceding claim, wherein the coupling link (42) connects the input link (41) to the output link (43), the input link (41) being an input rocker arm and the output link (43) being an output rocker arm.

9. An electric door lock assembly (1) according to any preceding claim, wherein the force required to move the latch member (20) from the blocking position (20b) to the releasing position (20r) exceeds the force delivered by the electric actuator (30).

10. An electric door lock assembly (1) according to claim 9, wherein the electric actuator (30) is a solenoid.

11. An electric door lock unit (1) according to any preceding claim, comprising- a biasing means (25) arranged to bias the locking means (20) towards the blocking position (20b), and- an auxiliary case (50) arranged to cooperate with the strike plate (120) between an engaged position (50e), in which the locking member (20) is blocked from movement, and a released position (50d), in which the locking member (20) is not blocked from movement,wherein the electric actuator (30) is arranged to move the locking member (20) from the blocking position (20b) to the release position (20r).