CONTROL MECHANISM FOR LOCK PAWL

Abstract

A control mechanism for a lock pawl comprises an electric motor mounted in a housing that is connected with the seat backrest and has an output shaft with a worm gear engaging with the spur gearing of a transmission gear rotary-mounted on a transmission pivot and having on its frontal surface an eccentric selector pivot for controlling the pawl of the lock, swing-mounted on a pawl pivot between a blocking position, in which the pawl blocks a rotary ratchet of the lock from releasing a catch eye connected with the car bodywork, and an unlocking position, in which the pawl releases the rotary ratchet to release the catch eye, the pawl having a radial selector arm, which in the blocking position of the pawl interferes with the circular trajectory of the selector pivot to enable the selector pivot to engage with the selector arm, whereas the pawl has a radial control arm.

Claims

1. A control mechanism for a lock pawl, particularly in a lock for a car seat backrest, comprising an electric motor (1) mounted in a housing (4) that is connected with the seat backrest and having an output shaft (2) with a worm gear (3) engaging with the spur gearing (12) of a transmission gear (11) rotary-mounted on a transmission pivot (13) and having on its frontal surface an eccentric selector pivot (15) for controlling the pawl (21) of the lock (5), swing-mounted on a pawl pivot (22) between a blocking position, in which the pawl (21) blocks a rotary ratchet (31) of the lock (5) from releasing a catch eye (35) connected with the car bodywork, and an unlocking position, in which the pawl (21) releases the rotary ratchet (31) to release the catch eye (35), the pawl (21) having a radial selector arm (24), which in the blocking position of the pawl (21) interferes with the circular trajectory of the selector pivot (15) to enable the selector pivot (15) to engage with the selector arm (24), wherein the pawl (21) has a radial control arm (25), which is angled against the radial selector arm (24) and interferes, in the unlocking position of the pawl (21) with the circular trajectory of the selector pivot (15) to block the movement of the selector pivot (15).

2. A control mechanism for a lock pawl according to claim 1, wherein for blocking movement of the selector pivot (15), the control arm (25) has a control protrusion (26), protruding in the tangential direction from the control arm (25) and having a stop area (27).

3. A control mechanism for a lock pawl according to claim 1, wherein the pawl (21) comprises a selector sleeve (42) with a selector arm (24) and a control sleeve (43) with a control arm (25), both the selector sleeve (42) and the control sleeve (43) being rotary-mounted side by side on the pawl pivot (22) and linked together with a link torsion spring (41).

4. A control mechanism for a lock pawl according to claim 3, wherein the angular distance between the control sleeve (43) and the selector sleeve (42) is adjustable.

5. A control mechanism for a lock pawl, particularly for a lock pawl of a car seat backrest, the control mechanism comprising an electric motor mounted in a housing that is connected with the seat backrest, the electric motor having an output shaft with a worm gear, the worm gear engaging with the spur gearing of a transmission gear, the transmission gear rotary-mounted on a transmission pivot and having on its frontal surface an eccentric selector pivot for controlling the pawl of the lock, the pawl mounted on a pawl pivot for swinging between a blocking position, in which the pawl blocks a rotary ratchet of the lock from releasing a catch eye connected with the car bodywork, and an unlocking position, in which the pawl releases the rotary ratchet to release the catch eye, the pawl having a radial selector arm, the radial selector arm in the blocking position of the pawl (21) interfering with the circular trajectory of the selector pivot for engagement of the selector pivot with the selector arm, the pawl (21) having a radial control arm, the control arm angled against the radial selector arm and interfering in the unlocking position of the pawl with the circular trajectory of the selector pivot to block the movement of the selector pivot.

6. A control mechanism for a lock pawl, the control mechanism comprising an electric motor mounted in a housing that is connected with the seat backrest, the electric motor having an output shaft with a worm gear, the worm gear engaging with the spur gearing of a transmission gear, the transmission gear rotary-mounted on a transmission pivot and having on its frontal surface an eccentric selector pivot for controlling the pawl of the lock, the pawl mounted on a pawl pivot for swinging between a blocking position, in which the pawl blocks a rotary ratchet of the lock from releasing a catch eye connected with the car bodywork, and an unlocking position, in which the pawl releases the rotary ratchet to release the catch eye, the pawl having a radial selector arm, the radial selector arm in the blocking position of the pawl interfering with the circular trajectory of the selector pivot for engagement of the selector pivot with the selector arm, the pawl having a radial control arm, the control arm angled against the radial selector arm and interfering in the unlocking position of the pawl with the circular trajectory of the selector pivot to block the movement of the selector pivot whereas for blocking movement of the selector pivot, the control arm having a control protrusion protruding in the tangential direction from the control arm and having a stop area.

7. A control mechanism for a lock, the control mechanism comprising an electric motor mounted in a housing that is connected with the seat backrest, the electric motor having an output shaft with a worm gear, the worm gear engaging with the spur gearing of a transmission gear, the transmission gear rotary-mounted on a transmission pivot and having on its frontal surface an eccentric selector pivot for controlling the pawl of the lock, the pawl mounted on a pawl pivot for swinging between a blocking position, in which the pawl blocks a rotary ratchet of the lock from releasing a catch eye connected with the car bodywork, and an unlocking position, in which the pawl releases the rotary ratchet to release the catch eye, the pawl having a radial selector arm, the radial selector arm in the blocking position of the pawl interfering with the circular trajectory of the selector pivot for engagement of the selector pivot with the selector arm, the pawl having a radial control arm, the control arm angled against the radial selector arm and interfering in the unlocking position of the pawl with the circular trajectory of the selector pivot to block the movement of the selector pivot, the pawl comprising a selector sleeve with a selector arm and a control sleeve with a control arm, both the selector sleeve and the control sleeve being rotary-mounted side by side on the pawl pivot and linked together with a link torsion spring.

8. A control mechanism for a lock pawl, the control mechanism comprising an electric motor mounted in a housing that is connected with the seat backrest, the electric motor having an output shaft with a worm gear, the worm gear engaging with the spur gearing of a transmission gear, the transmission gear rotary-mounted on a transmission pivot and having on its frontal surface an eccentric selector pivot for controlling the pawl of the lock, the pawl mounted on a pawl pivot for swinging between a blocking position, in which the pawl blocks a rotary ratchet of the lock from releasing a catch eye connected with the car bodywork, and an unlocking position, in which the pawl releases the rotary ratchet to release the catch eye, the pawl having a radial selector arm, the radial selector arm in the blocking position of the pawl interfering with the circular trajectory of the selector pivot for engagement of the selector pivot with the selector arm, the pawl having a radial control arm, the control arm angled against the radial selector arm and interfering in the unlocking position of the pawl with the circular trajectory of the selector pivot to block the movement of the selector pivot, the pawl (21) comprising a selector sleeve with a selector arm and a control sleeve with a control arm, both the selector sleeve and the control sleeve being rotary-mounted side by side on the pawl pivot and linked together with a link torsion spring, whereas the angular distance between the control sleeve and the selector sleeve is adjustable.

9. A control mechanism for a lock pawl according to claim 2, wherein the pawl (21) comprises a selector sleeve (42) with a selector arm (24) and a control sleeve (43) with a control arm (25), both the selector sleeve (42) and the control sleeve (43) being rotary-mounted side by side on the pawl pivot (22) and linked together with a link torsion spring (41).

Description

OVERVIEW OF FIGURES IN THE DRAWINGS

[0012] The lock pawl control mechanism according to the invention is explained using drawings, wherein

[0013] FIG. 1 shows a section through the lock in the pawl blocking position;

[0014] FIG. 2 shows a section through the lock in the pawl unlocking position during engagement of the selector pivot with the selector arm;

[0015] FIG. 3 shows a section through the lock in the pawl unlocking position during engagement of the control protrusion of the control arm with the selector pivot.

LIST OF EXPLANATORY SYMBOLS

[0016] 1 electric motor [0017] 2 output shaft [0018] 3 worm gear [0019] 4 housing [0020] 5 lock [0021] 11 transmission gear [0022] 12 spur gearing [0023] 13 transmission pivot [0024] 15 selector pivot [0025] 21 pawl [0026] 22 pawl pivot [0027] 23 pawl spring [0028] 24 selector arm [0029] 25 control arm [0030] 26 control protrusion [0031] 27 stop area (for selector pin 15) [0032] 28 stop area (for blocking element) [0033] 31 ratchet [0034] 32 ratchet pivot [0035] 35 catch eye [0036] 40 pawl torsion spring [0037] 41 link torsion spring [0038] 41a first end [0039] 41b second end [0040] 42 selector sleeve [0041] 43 control sleeve [0042] 50 blocking arm [0043] 51 auxiliary pawl [0044] 52 (auxiliary pawl) arm [0045] 53 electric switch

Example Embodiment of the Control Mechanism According to the Invention

[0046] According to FIG. 1, the electric motor (1) of the pawl control mechanism is mounted in a housing (4) connected with a seat backrest. The electric motor (1) has an output shaft (2) with a worm gear (3), which engages with the spur gearing (12) of the transmission gear (11), rotary-mounted on the transmission pivot (13). The transmission gear (11) has on its frontal surface an eccentric selector pivot (15) for controlling the pawl (21) of the lock (5). The pawl (21) is swing-mounted on the pawl pivot (22) between a blocking position, in which the pawl (21) blocks the rotary ratchet (31) of the lock (5) against releasing the catch eye (35) connected with the car bodywork, and an unlocking position, in which the pawl (21) releases the rotary ratchet (31) to release the catch eye (35). The ratchet (31) is rotary-mounted in the housing (4) on the ratchet pivot (32). The catch eye (35) interferes, in the specified position of the ratchet (31), with the U-shaped notch (34), which runs at least partly radially. The blocking arm (50) is also rotary-mounted on the ratchet pivot (32). The pawl (21) comprises a radial arm (25), which according to FIG. 1 engages with the radial arm (33) of the ratchet. As a consequence of the force contact between the radial arm (25) of the pawl (21) and the radial arm (33) of the ratchet (31), the pawl (21) blocks the ratchet (31) in the locked position so that the catch eye (35) cannot be released. The housing (4) also contains an electric switch (53) with a contact element, which is ready to indicate contact of the control arm (25) of the pawl (21) in the position into which the pawl (21) is moved according to FIG. 2 below. The pawl (21) has a radial selector arm (24) and a radial control arm (25), which are angled against each other and interfere, in a certain position of the pawl (21), with the circular trajectory of the selector pivot (15). According to FIG. 1, the pawl (21) is in the blocking position. In the blocking position of the pawl (21), the selector arm (24) of the pawl (21) interferes with the circular trajectory of the selector pivot (15) to make the selector pivot (15) engage with the selector arm (24). The position of the selector pivot (15) according to FIG. 1 is the initial position, in which the lock control mechanism is when the seat backrest is lifted and locked. After the unlocking of the lock (5) is activated by bringing electric current to the electric motor (1), the transmission worm gear (3) and the spur gearing (2) make the transmission gear (11) with the selector pivot (15) rotate counterclockwise, the selector pivot (15) hits the selector arm (24) and its force contact with the selector arm makes the selector pivot (15) start turning the pawl (21) against the force of the torsion pawl spring (40) clockwise into the unlocking position, shown in FIG. 2.

[0047] According to FIG. 2, the selector pivot (15) has, by force contact with the selector arm (24), turned the pawl (21) clockwise into the unlocking position. The pawl (21) has a radial selector arm (24) and a radial control arm (25), which are angled against each other under the angle . The pawl (21) is in the unlocking position, in which the control arm (25) of the pawl (21) is not in force contact with the ratchet (31) and the ratchet (31) is free to rotate clockwise around the pivot (32) to release the catch eye (35) from the notch (34) and to enable tilting of the seat backrest down from its upright position. In the unlocking position, the pawl (21) according to FIG. 1 is held by an auxiliary pawl (51), rotary-mounted in the housing (4) against the force of the torsion spring. The auxiliary pawl 51 has a radial arm (52), which touches the control arm (25) or the control protrusion (26) by force contact and exerts a force in the tangential direction on the pawl (21), blocking the pawl (21) against its counterclockwise movement, thus preventing the pawl (21) from returning to the blocking position. According to FIG. 2, the return to the blocking position can be prevented by the loose end of the blocking arm (50) after the ratchet (31) has titled clockwise and released the catch eye (35) from the notch (34). After the tilting of the ratchet (31), the blocking arm (50) turns clockwise by action of its own torsion spring and its loose end is fastened, instead of the auxiliary pawl (51), in the stop area (28) of the control arm (25). The loose end of the control arm (25) has activated a contact of the electric switch (53), which sends a signal and information about the pawl (21) reaching its unlocking position, i.e., information about the seat backrest becoming unlocked. For blocking movement of the selector pivot (15), the control arm (25) has a control protrusion (26), protruding in the tangential direction from the control arm (25) and having a stop area (27). In the unlocking position of the pawl (21), the control arm (25) of the pawl (21) interferes, with its control protrusion (26), in the circular trajectory of the selector pivot (15). The transmission gear (11), driven via the transmission elements shown by the electric motor (1), continues rotating counterclockwise and the selector pivot (15), by its force action on the selector arm (24), turns the pawl (21) farther against the force of the pawl spring (40), the selector pivot (15) runs past the selector arm (24), disengages from the selector arm (24) and continues rotating along its circular trajectory. After disengaging from the selector arm (24), the selector pivot (15) stops exerting force on the selector arm (24). The pawl (21) is under the force action of the pawl torsion spring (40), but does not return counterclockwise to the blocking position according to FIG. 1, because that is prevented by the arm (52) of the auxiliary pawl (51) or the loose end of the blocking arm (50), which exerts a force on the stop area (28) of the pawl. After disengaging from the selector arm (24), the selector pivot (15) continues rotating along its circular trajectory until it hits the stop area (27) for stopping the selector pivot (15), as shown in FIG. 3.

[0048] In FIG. 3, the selector pivot (15) of the transmission gear 11 is shown stopped at the stop area (27) of the control protrusion (26) of the control arm (25), when the rotation of the transmission gear (11) stops. As a consequence of the stopping, the current load on the electric motor (1) increases sharply and the current supply to the electric motor (1) is deactivated. The selector pivot (15) stops exerting the force on the stop area (27). When the backrest is lifted from the tilted to the upright position, the catch eye (35) moves in a direction tangential to the ratchet pivot (32) and turns the ratchet (31) counterclockwise by force, making it enter in a retrograde movement the position shown in FIG. 1 and thus locking the lock (5). During this retrograde movement, the ratchet (31) disengages, by a force action on the blocking arm (50), the blocking arm (50) or the auxiliary pawl (51) from the stop area (28) of the control arm (25), thus releasing the pawl (21) for its retrograde movement into the blocking position. During the retrograde movement of the pawl (21), the control protrusion (26) disengages from the selector pivot (15), but the selector pivot (15) still remains in the position according to FIG. 3, until the next activation of the electric motor. The position of the selector pivot (15) according to FIG. 3 is the initial position of the selector pivot (15) for the unlocking of the lock (5). According to FIG. 3, the pawl (21) can be made of two pieces and comprise a selector sleeve (42) and a control sleeve (43), between which there can be a link torsion spring (41), which links the selector sleeve (42) and the control sleeve (43). The selector sleeve (42) and the control sleeve (43) are rotary-mounted side by side on a single pawl pivot (22). The selector sleeve (42) has a selector arm (24) and the control sleeve (43) has a control arm (25). This alternative arrangement can be used to eliminate noisy impacts of parts and achieve a softer stopping effect. At an advantage, the angular distance between the control sleeve (43) and the selector sleeve (42) can be adjustable.