MECHANISM FOR LOCKING A PEDAL ON AN IMPLEMENT-CARRYING VEHICLE

Abstract: A locking mechanism for locking a foot pedal, which is arranged on an implement-carrying vehicle supporting an implement and which is coupled to the implement with a view to moving the same between a lowered working position and a raised transport position, has a guide (12), which is connected to the vehicle, and a slide (13), which is connected to the foot pedal and arranged to be displaced along the guide during the movement of the foot pedal. The slide (13) supports a rotatable star wheel (23) having several points. The guide (12) has abutment members (18', 20), which are arranged to co-operate with the star wheel (23) during the movement of the foot pedal and thus the slide (13) with a view to turning the star wheel to different turning positions, which are dependent on the displacement phases of the slide (13). In one of these turning positions, in which the star wheel (23) is situated when the foot pedal is situated in a position corresponding to the raised transport position of the implement, the star wheel (23) engages the guide (12) and one (18') of its abutment members (18', 20) and prevents the slide (13) and thus the foot pedal from being displaced towards a position, which corresponds to the lowered working position of the implement.

Description: MECHANISM FOR LOCKING A PEDAL ON AN IMPLEMENT-CARRYING VEHICLE The present invention relates to a locking mechanism for locking a foot pedal, which is arranged on an implement-carrying vehicle supporting an implement and which is coupled via a coupling device to the implement with a view to moving the same between a lowered working position and a raised transport position, the foot pedal being movable relative to the vehicle between a first position and a second position, which correspond to the lowered working position and the raised transport posi- tion, respectively, of the implement, the foot pedal being pressed via the coupling device, due to the weight of the implement, towards its first position and the locking mechanism being arranged to lock the foot pedal in its second position and thus the implement in its raised transport position. Our co-pending Swedish patent application No. 9901091-0, filed on 25 March 1999, discloses an implement-carrying vehicle having a front-mounted implement, in particular a ride-on lawnmower having a front- mounted lawnmower assembly, in which vehicle a foot pedal is used for operating the implement. The foot pedal is coupled to the implement via a coupling device with a view to moving the implement between a lowered working position and a raised transport position. The foot pedal is movable between a first position and a second position, which correspond to the lowered working position and the raised transport position, respectively, of the implement. The foot pedal is maintained in its first position due to the weight of the implement and does not need to be locked in this position. When the foot pedal is situated in its second position, the implement thus being in its raised transport position, the foot pedal must, however, be locked for the implement to be maintained in its transport position in a safe manner. The object of the present invention is to provide a reliable mechanism which functions automatically to pro- vide such locking of a foot pedal in an implement-carrying vehicle of this type. According to the present invention, this object is achieved by means of a locking mechanism, which is of the kind mentioned by way of introduction and characterised in that the locking mechanism has a guide, which is connected to the vehicle and consists of a tube, and a slide, which is connected to the foot pedal and consists of a tube arranged around the guide, said slide being ar- ranged to be displaced along the guide, during the movement of the foot pedal, between an upper position and a lower position, that the slide supports a rotatable star wheel having several points and that the guide has an upper abutment means and a lower abutment means, the star wheel and the abutment means being designed and placed in such manner that, when the foot pedal is depressed from its first position for lifting the implement and moved slightly beyond its second position, the star wheel abuts against the lower abutment means near the lower position of the slide and is turned by said lower abutment means to a first turning position, in which a first point of the points of the star wheel is in an engaging position in order to engage the upper abutment means, when the foot pedal is released and moved upwards a distance due to the weight of the implement towards its second position, said upper abutment means then turning the star wheel to a second turning position, in which a second point of the points of the star wheel is engaged with the guide, in such manner that the star wheel is prevented from continuing to turn at the same time as said first point of the star wheel is engaged with the upper abutment means and together with said second point of the star wheel prevents a continued displacement upwards of the slide and thus a continued movement upwards of the foot pedal from its second position, and that the star wheel near the lower position of the slide, when the foot pedal is depressed a distance from its second position, abuts against the lower abutment means and is turned by the same to a third turning position, in which said second point of the star wheel is in an engaging position to engage the upper abutment means, when the foot pedal is released and moved upwards due to the weight of the implement, said upper abutment means then turning the star wheel to a fourth turning position, in which the star wheel can pass the upper abutment means, during the displacement upwards of the slide, without the star wheel and thus the slide being stopped, so that the star wheel is moved beyond the upper abutment means in the continued movement upwards of the foot pedal to its first position. In a preferred embodiment, the star wheel has four points, and the star wheel and the abutment means are designed and arranged in such manner that, when the foot pedal, in a subsequent second cycle, is depressed the next time from its first position for lifting the implement and is moved slightly beyond its second position, then released and moved upwards a distance, due to the weight of the implement, towards its second position, then depressed a distance from its second position and finally released and moved upwards due to the weight of the implement, the third point and the fourth point of the star wheel take over the function that the first and the second points, respectively, had in the preceding cycle, the first point and the second point of the star wheel taking over said function once again in a subsequent third cycle, etc. The guide as well as the slide suitably consist of a quadrangular tube . In a preferred embodiment, the guide has a longitudinal slot in each of two opposed tube walls, the two slots being located opposite each other and the slide supporting a pivot, which extends through the two slots of the guide and on which the star wheel is rotatably mounted inside the guide. The guide preferably has a rectangular opening in one of its walls, which are situated between said opposed tube walls, said opening having an upper boundary edge, which forms the upper abutment means of the guide. In a preferred embodiment, the two slots of the guide are slightly displaced in relation to the longitu- dinal centre line of the respective tube walls towards the tube wall in which the rectangular opening is formed, and the lower abutment means of the guide consists of a pin, which extends between said opposed tube walls of the guide a distance below the lower end of the slots and is slightly displaced in relation to said centre line in the direction away from the tube wall in which the rectangular opening is formed. The invention will now be described in more detail with reference to the accompanying drawings . Figs 1 and 2 are schematic lateral views showing the front portion of a ride-on lawnmower having a lawnmower assembly in a lowered position and a raised position, respectively. Fig. 3 is a perspective view showing a locking mecha- nism according to the invention which is mounted on the ride-on lawnmower. Fig. 4 is a perspective view corresponding to Fig. 3 but showing the locking mechanism in longitudinal cross- section. Figs 5-15 are longitudinal sectional views showing the locking mechanism in different positions depending on the position of a foot pedal. The ride-on lawnmower 1 which is shown in Figs 1 and 2 has a wheel-mounted chassis 2 and carries a front- mounted lawnmower assembly 3. The lawnmower assembly 3 is pivotably mounted on the front-wheel axle 4 of the ride-on lawnmower 1 and is pivotable between a lowered working position (Fig. 1) and a raised transport position (Fig. 2) . The ride-on lawnmower 1 further has a foot pedal 5 which is operable by the driver to raise and lower the lawnmower assembly 3. The lawnmower assembly 3 is coupled to the foot pedal 5 by means of a link arm 6. The foot pedal 5 has a front lever arm 7, which is coupled via the link arm 6 to the lawnmower assembly 3, and a rear lever arm 8, which supports a foot plate 9 at its rear end. The two lever arms 7 and 8 are non- rotatably connected to a transverse pivot 10, which is rotatably mounted in a pivot mounting 11 which is fixedly connected to the chassis 2. The rear lever arm 8 is substantially Y-shaped and has two front Y-branches, which are substantially paral- lei to each other and non-rotatably connected to the pivot 10 on each side of the front lever arm 7. The foot plate 9 is attached to the Y-base of the rear lever arm 8. When the lawnmower assembly 3 is in its lowered working position, the foot pedal 5 is situated in an upper first position, as shown in Fig. 1. When depressing the foot pedal 5 from this first position, the lawnmower assembly 3 is lifted to its raised transport position (Fig. 2) . When the lawnmower assembly 3 is in its raised transport position, the foot pedal 5 is situated in a second position. The foot pedal 5 is pressed due to the weight of the lawnmower assembly 3 via the link arm 6 towards its first position. A locking mechanism, which is arranged to lock the foot pedal 5 in its second position, has a guide 12 which is connected to the chassis 2 of the ride-on lawnmower 1 and a slide 13, which is connected to the rear lever arm 8 of the foot pedal 5 and which is displaceable along the guide 12 between an upper position and a lower position. The guide 12 consists of an inner tube which is square in cross-section, and the slide 13 consists of a shorter outer tube which is arranged around the guide and which is square in cross-section, the inner dimensions of the outer tube being substantially the same as the outer dimensions of the inner tube. The guide 12 is connected to the chassis 2 by means of a brace 14, whose web portion is attached to the chassis by means of a screw-nut connection 15 and between the legs of which the guide 12 is supported. The guide 12 is pivotable on a pivot 16 in the form of a bolt which extends through the tube walls in one of the pairs of the mutually opposed inner tube walls of the guide in the lower portion of the guide. The pivot 16 is parallel to the pivot 10. The guide 12 has a longitudinal slot 17 in each of the tube walls in the other pair of the mutually opposed inner tube walls of the guide. The guide 12 further has a rectangular opening 18 in one (19) of the tube walls in said one pair of mutually opposed inner tube walls. This opening 18 is located slightly below the middle of the guide 12 (see for instance Fig. 5) . The upper boundary edge 18' of the opening 18 forms an upper abutment means. The two slots 17 of the guide 12 are displaced, in relation to the longitudinal centre line of the inner tube wall in which the respective slots are formed, towards the inner tube wall 19 in which the opening 18 is formed (see for instance Fig. 5) . A pin 20, which forms a lower abutment means, extends between the tube walls in said other pair of mu- tually opposed inner tube walls of the guide 12 a distance below the lower end of the slots 17. This pin 20 is slightly displaced in relation to said centre line in the direction away from the tube wall 19 in which the opening 18 is formed. The slide 13 is rotatably connected to the foot pedal 5 by means of two pivot pins 21, which are axially aligned with each other and which project from the slide in the lower portion of the same, said pivot pins being mounted in a respective one of the two Y-branches of the rear lever arm 8. The pivot pins 21 are parallel to the pivots 10 and 16. The slide 13 supports a pivot 22, which is perpendicular to the pivot pins 21 and extends through the two slots 17 of the guide 12 and supports inside the guide a star wheel 23 which is rotatable on the pivot 22. The slide 13 has a rectangular opening 24 in the outer wall which runs along the inner tube wall 19 in which the rectangular opening 18 of the guide 12 is formed. The opening 24 is located slightly above the middle of the slide 13 (see for instance Fig. 5) . The star wheel 23 essentially has the shape of a right-angled parallelepiped, which has a first pair of parallel long sides, through which the pivot 22 extends at right angles, two parallel short sides each having a substantially V-shaped recess and a second pair of parallel long sides. The star wheel 23 thus has four points A, B, C and D. The shape and function of the star wheel 23 and its co-operation with the lower abutment means (the pin 20) and the upper abutment means (the upper boundary edge 18' of the opening 18) is best explained by the description below of the function of the locking mechanism. Below, the function of the locking mechanism will be described in more detail starting from an initial position (Figs 1 and 5) , in which the lawnmower assembly 3 is situated in its lowered working position, the foot pedal 5 is situated in its first position, in which it is maintained due to the weight of the lawnmower assembly 3 , and the slide 13 is situated in its upper position, in which the pivot 22 supporting the star wheel 23 engages the upper end limits of the slots 17 or is at least very close to the same. In this initial position, the long sides of the second pair of parallel long sides of the star wheel 23 extend parallel with the inner tube wall 19, the points A, B, C and D, in this turning position of the star wheel 23, constituting the upper right-hand corner, lower right-hand corner, lower left-hand corner and upper left-hand corner, respectively, of the star wheel (referring to Figs 5-15) . When the foot pedal 5 is depressed from its first position to lift the lawnmower assembly 3, the slide 13 and thus the star wheel 23 are displaced downwards, the star wheel, as shown in Fig. 6, keeping the same turning position as in the initial position. When the star wheel 23 abuts against the pin 20 (Fig. 7) near the lower posi- tion of the slide 13, which happens when the rectangular opening 24 of the slide 13 is situated approximately in front of the rectangular opening 18 of the guide, it is turned by the pin 20 a distance in the clockwise direction with reference to Figs 5-15 to a first turning posi- tion (Fig. 8), in which the point A of the star wheel extends into the opening 18 of the guide 12 and takes an engaging position. When in this position the foot pedal 5 is released, which here means that the force of depression is cau- tiously reduced, the foot pedal is moved, due to the weight of the lawnmower assembly 3, a distance upwards towards its second position. The corner A of the star wheel 23 will then engage the upper boundary edge 18' of the opening 18 (See Fig. 9) , which then turns the star wheel 23 in the clockwise direction to a second turning position (Fig. 10), in which the point D of the star wheel engages the inner tube wall 19, which then prevents the star wheel 23 from continuing to turn in the clockwise direction. As the point A of the star wheel is still engaged with the edge 18', it thus prevents together with the point D of the star wheel a continued displacement upwards of the slide 13 and thus a continued movement upwards of the foot pedal 5 from its second position, which corresponds to the position of the slide 13 which is shown in Fig. 10. When the lawnmower assembly 3 is to be lowered down to its working position, the foot pedal 5 is depressed a distance from its second position, the star wheel 23 abutting against the pin 22 (Fig. 11) near the lower position of the slide 13 and being turned by said pin a distance in the clockwise direction to a third turning position (Fig. 12) , in which the point D of the star wheel extends through the opening 18 of the guide 12 a distance into the opening 24 of the slide 13 and takes an engaging position. When the foot pedal 5 is now released, it is moved upwards due to the weight of the lawnmower assembly 3, the point D of the star wheel engaging the upper boundary edge 18' of the opening 18 (Fig. 13) , said boundary edge then turning the star wheel 23 in the clockwise direction to a fourth turning position (Fig. 14) , in which the star wheel 23 has been turned half a revolution in the clockwise direction in relation to the position shown in Figs 5-8, i.e. that the points A, B, C and D in the fourth turning position constitute the lower left-hand corner, upper left-hand corner, upper right-hand corner and lower right-hand corner, respectively, of the star wheel 23 (referring to Figs 5-15) . In the fourth turning position, the star wheel 23 can thus pass the upper boundary edge 18' of the opening 18 without being stopped during the displacement upwards of the slide 13. In the continued movement up- wards of the foot pedal 5, the star wheel 23 is thus moved beyond the boundary edge 18 ' . When the foot pedal 5 has thus been returned to its first position (Fig. 15) , the locking mechanism is back to the above-described initial position, the star wheel 23 having been turned, however, through 180° in the clockwise direction. When repeating the above-described cycle, which comprises the steps of depressing the foot pedal 5 from its first position (the working position of the lawnmower assembly 3) , letting up the foot pedal from the position which corresponds to the lower position of the slide 13 to the second position of the foot pedal (the transport position of the lawnmower assembly 3) , depressing the foot pedal from its second position and letting up the foot pedal to its first position, the above-described process is carried out in the same manner, except that the function of the point A and the point D is taken over by the point C and the point B, respectively. When the cycle has been carried out a second time, the star wheel 23 has been turned through yet another 180° in the clockwise direction and is once again back to the initial position shown in Fig. 5.

Claims: CLAIMS 1. A locking mechanism for locking a foot pedal (5), which is arranged on an implement-carrying vehicle (1) supporting an implement (3) and which is coupled via a coupling device (6) to the implement with a view to moving the same between a lowered working position and a raised transport position, the foot pedal (5) being movable relative to the vehicle (1) between a first position and a second position, which correspond to the lowered working position and the raised transport position, respectively, of the implement (3) , the foot pedal (5) being pressed via the coupling device (6) , due to the weight of the implement (3) , towards its first position and the locking mechanism being arranged to lock the foot pedal (5) in its second position and thus the implement (3) in its raised transport position, c ha ra c t e r i s e d in that the locking mechanism has a guide (12) , which is connected to the vehicle (1) and consists of a tube, and a slide (13), which is connected to the foot pedal (5) and consists of a tube arranged around the guide, said slide being arranged to be displaced along the guide, during the movement of the foot pedal, between an upper position and a lower position, that the slide (13) supports a rotatable star wheel (23) having several points (A, B, C, D) and that the guide (12) has an upper abutment means (18') and a lower abutment means (20) , the star wheel (23) and the abutment means (18', 20) being designed and placed in such manner that, when the foot pedal (5) is depressed from its first position for lifting the implement (3) and moved slightly beyond its second position, the star wheel (23) abuts against the lower abutment means (20) near the lower position of the slide (13) and is turned by said lower abutment means to a first turning position, in which a first point (A) of the points (A, B, C, D) of the star wheel (23) is in an engaging position in order to engage the upper abutment means (18') , when the foot pedal (5) is released and moved upwards a distance due to the weight of the implement (3) towards its second position, said upper abutment means then turning the star wheel (23) to a second turning position, in which a second point (D) of the points (A, B, C, D) of the star wheel (23) is engaged with the guide (12), in such manner that the star wheel (23) is prevented from continuing to turn at the same time as said first point (A) of the star wheel is engaged with the upper abutment means (18') and together with said second point (D) of the star wheel prevents a continued displacement upwards of the slide (13) and thus a continued movement upwards of the foot pedal (5) from its second position, and that the star wheel (23) near the lower position of the slide (13) , when the foot pedal (5) is depressed a distance from its second position, abuts against the lower abutment means (20) and is turned by the same to a third turning position, in which said second point (D) of the star wheel is in an engaging position to engage the upper abutment means (18'), when the foot pedal (5) is released and moved upwards due to the weight of the implement (3) , said upper abutment means then turning the star wheel (23) to a fourth turning position, in which the star wheel can pass the upper abutment means (18'), during the displacement upwards of the slide (13) , with- out the star wheel and thus the slide being stopped, so that the star wheel (23) is moved beyond the upper abutment means (18') in the continued movement upwards of the foot pedal (5) to its first position. 2. A locking mechanism as claimed in claim 1, charac t e ri s e d in that the star wheel (23) has four points (A, B, C, D) , and that the star wheel (23) and the abutment means (18', 20) are designed and ar- ranged in such manner that, when the foot pedal (5), in a subsequent second cycle, is depressed the next time from its first position for lifting the implement (3) and is moved slightly beyond its second position, then released and moved upwards a distance, due to the weight of the implement (3) , towards its second position, then depressed a distance from its second position and finally released and moved upwards due to the weight of the implement (3) , the third point (C) and the fourth point (B) of the star wheel (23) take over the function that the first and the second points, respectively (A and D, respectively) , had in the preceding cycle, the first point (A) and the second point (D) of the star wheel (23) taking over said function once again in a subsequent third cycle, etc. 3. A locking mechanism as claimed in claim 1 or 2 , cha ra c t e ri s e d in that the guide (12) as well as the slide (13) consist of a quadrangular tube. 4. A locking mechanism as claimed in claim 3, c h a r a c t e r i s e d in that the guide (12 ) has a longitudinal slot (17) in each of two opposed tube walls, the two slots (17) being located opposite each other, and that the slide (13) supports a pivot (22) , which extends through the two slots (17) of the guide (12) and on which the star wheel (23) is rotatably mounted inside the guide . 5. A locking mechanism as claimed in claim 4, charac t e ri s e d in that the guide (12) has a rectangular opening (18) in one (19) of its walls, which are situated between said opposed tube walls, said opening (18) having an upper boundary edge (18'), which forms the upper abutment means of the guide (12) . 6. A locking mechanism as claimed in claim 5, c ha ra c t e r i s e d in that the two slots (17) of the guide (12) are slightly displaced in relation to the longitudinal centre line of the respective tube walls towards the tube wall (19) in which the rectangular opening (18) is formed, and that the lower abutment means of the guide (12) consists of a pin (20) , which extends between said opposed tube walls of the guide (12) a distance below the lower end of the slots (17) and is slightly displaced in relation to said centre line in the direction away from the tube wall (19) in which the rectangular opening (18) is formed.

Inventors: LUNDBERG PETER, LUNDBERG, PETER
Applicants: LUNDBERG PETER, STIGA AB, LUNDBERG, PETER
Application year: 2000
Main classification: A01B71
IPC codes: A01B63, A01B73, F16B7, G05G5