Bicycle pedal

Abstract: This invention relates to a connecting structure between a bicycle pedal (2) and a cleat (30) comprising hooks (4,5) pivotably supported by a pedal body (2) for engaging and releasing the cleat (30), and an urging device for urging the hooks toward engaging positions. (30a,30b) The object of this invention is to allow the cleat to be released with increased reliability when, for example, the cyclist falls over with his shoe becoming obliquely inclined relative to the pedal. A first cam mechanism (20d) is provided between each of the hooks (4,5) and the cleat (30) for causing the hook to pivot in a releasing direction when the cleat is inclined about a first imaginary axis extending substantially along a direction of pivotal movement of the hooks. The first cam mechanism (20d) includes a first pressed edge defined on one of the hooks and opposed to the cleat, and a first pressing edge (30a) defined on the cleat and opposed to one of the hooks for slidable contact with the first pressed edge. The first pressed edge and first pressing edge overlap each other as seen in a direction perpendicular to a tread of the pedal body.

Description: BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION The present invention relates to a pedal particularly to a bicycle. 2. DESCRIPTION OF THE PRIOR ART A bicycle pedal according to the preamble of the main claim is known (GB-A-2202499). It is comprised with the front and the rear cleat hook and the cleat contact plate positioned there between. The rear hook is pivotably supported by the pedal and is comprised with urging means for urging the rear hook toward a cleat engaging position, whereby the rear cleat hook is moved to a disengaging position by rotation of the cleat in its own plane. Further there are cleat movement restricting means for restricting the forward movement of the cleat. When the hooks are provided at the front end of the pedal body as well as the rear end thereof, a great pressure applied forwardly of the pedal could result in disengagement between the front hook and the cleat, whereby the cleat inadvertently becomes disengaged from the pedal. SUMMARY OF THE INVENTION It is an object of the invention, therefore, to provide a pedal which prevents disengagement even when great pressure is applied from the cleat to the front hook. The object above is fulfilled by a pedal according to the claim. Having regard to the above situation, a pedal according to the present invention comprises a pedal body further including forward movement stoppers for contacting the cleat engaged by the hooks to prevent movement of the cleat forwardly of the pedal and allow rotation of the cleat about the second imaginary axis. In this construction, the forward movement stoppers are effective to prevent the front hook from pivoting forwardly of the pedal body when a great forward pressure acts on the front hook. The cleat in the engaged state will not move away from the tread of the pedal, and therefore will not move over the forward movement stoppers. Thus, when a great pressure acts on the cleat such as when the cyclist pedals the bicycle with full force or suddenly applies brakes, the front hook is free from the pressure and the cleat remains engaged without allowing the shoe to inadvertently separate from the pedal. The connecting structure including the forward movement stoppers realizes optimal hooks for allowing the cleat to be engaged by the pedal through a treading operation relative to the pedal. This is possible because no means is necessary for retarding the forward pivotal movement of the front hook. In addition, the forward movement stoppers allow the cleat to rotate about an imaginary axis. Thus, the cleat may be rotated to readily disengage from the pedal. In this aspect of the invention, the cleat separation may be further facilitated if the rear end of the cleat, which may be rotated or swung most easily from the point of view of human engineering, is rotatable about an axis. Other objects, features and advantages of the present invention will be apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing a relationship between a cleat and a pedal, Figs. 2 and 3 are sectional views showing a relationship between the rear end of the cleat and a rotation restriction portion, and Figs. 4 and 5 are schematic plan views showing the relationship between the rear end of the cleat and the rotation restricting portion. Figs. 6 and 7 are views showing modifications made to the embodiment. As shown in Fig. 1 a cleat 30 includes a front engaging portion 30a and a rear engaging portion 30b for engagement with a front hook 4 and a rear hook 5, respectively. The front engaging portion 30a has a semicircular top 30c of a half cylinder projecting from a top surface thereof. The rear engaging portion 30b defines a second pressing edge 30f projecting upwardly. The front engaging portion 30a defines oblique contact portions 30d at opposite sides thereof for contacting forward movement stoppers 20a to be described hereunder. As shown in Figs. 1, 2, and 5, a cleat contact plate 20 formed of steel has right and left front corners bent upward. Each of these upwardly bent portions defines an oblique forward movement stopper 20a for contacting the contact portion 30d of the cleat 30, and a rotation restrictor 20b for contacting a side of the front engaging portion 30a. Further, the cleat contact plate 20 has right and left rear portions bent upward. Each of these upwardly bent portions defines a rear rotation restrictor 20c for contacting a side of the cleat 30. The two rear rotation restrictors 20c are inclined in a way to diverge upwardly away from a tread 2' of the pedal body 2, thereby defining cam surfaces 20d. When the cleat 30 is engaged by the hooks 4 and 5, as shown in Fig. 5, the front rotation restrictors 20b contact the opposite sides at the front end of the cleat 30 to prevent lateral movement of the front end of the cleat 30, and the forward movement stoppers 20a contact the oblique contact portions 30d of the cleat 30 to prevent forward movement of the cleat 30. The rear end of the cleat 30, by the action of the cam surfaces 20d, remains away from the tread 2' of the pedal body 2 in the absence of a treading force. When a treading force is applied, the cam surfaces 20d act as the rear rotation restrictors 20c to prevent lateral movement of the rear end of the cleat 30. Consequently, the rotation of the cleat 30 about the imaginary axis X is prevented mainly when a treading force is applied. The way in which the connecting structure between the bicycle pedal body 2 and cleat 30 behaves will be described next. As shown in Fig. 1, when the cleat 30 attached to the shoe bottom S is pressed down on one of the treads 2' of the pedal body 2, the hooks 4 and 5 pivot in directions away from the pedal body 2 through contact with the inclined surfaces formed under the engaging portions 30a and 30b. Thereafter the hooks 4 and 5 pivot in directions toward the pedal body 2 and engage the engaging portions 30a and 30b, respectively. This completes the connection between the shoe and pedal body 2 as shown in Figs. 2, and 5, Since both of the hooks 4 and 5 pivot at this time, the treading action with respect to the pedal body 2 may be carried out in a direction substantially perpendicular to the tread 2' of the pedal body 2. In addition, the rear end of the cleat 30 is guided to a correct position by the cam surfaces 20d, so that the cyclist may pay little attention to the treading position relative to the pedal body 2. For disconnecting the shoe from the pedal body 2, the cleat may just be turned about the imaginary axis X as shown in Figs. 3 and 4, with no treading force applied to the rear end of the cleat 30. At this time, the front end of the cleat 30 is restrained from lateral movement by the front rotation restrictors 20b, so that the imaginary axis X extends through a position adjacent the front rotation restrictors 20b. The rear hook 5 pivots rearwardly through a relative sliding movement between the second pressing edge 30f at the rear end of the cleat 30 and a cam surface 5b of the rear hook 5. The cleat 30 is thereby disengaged from the hooks 4 and 5 to complete disconnection between the shoe and the pedal body 2. In this way, the cyclist can positively select connection or disconnection of the cleat 30 or shoe to/from the pedal body 2 according to circumstances. In an emergency such as when the cyclist falls over, the treading force is at least temporarily removed from the pedal body 2. The cleat 30 may become disengaged from the pedal body 2 through a behavior similar to the intentional operation described above, thereby to secure safety of the cyclist. In this case, the rear end of the cleat 30 moves away from the tread 2' of the pedal body 2 under the guiding action of the cam surfaces 20d. The cleat 30 becomes disengaged from and moves away from the rear hook 5, so that inadvertent re-engagement between the cleat 30 and the rear hook 5 is positively avoided. In this embodiment, the rear rotation restrictors 20c and cam surfaces 20d are arranged to contact the cleat 30. However, these components may be adapted to contact the shoe bottom S. The pedal body 2 may include projections formed on each tread thereof and defining the rear rotation restrictors 20c acting as cam surfaces 20d, the rear rotation restrictors 20c being arranged to contact surfaces F2 in holes defined in the shoe bottom S Fig. 6. The shoe bottom S is restrained from rotation about the imaginary axis X by the contact between the rear rotation restrictors 20c and the surfaces F2. The shoe bottom S and cleat 30 are movable away from the tread 2' of the pedal body 2 with rotation about the imaginary axis X of the shoe bottom S. While the cam surfaces 20d are provided on the rear rotation restrictors 20c in the second embodiment and modification 6 above, the cam surfaces 20d may be formed on the cleat 30 or shoe bottom S only or may by formed on the cleat 30 or shoe bottom S as well as the rear rotation restrictors 20c. As shown in Fig. 7 for example, the rear rotation restrictors 20c may extend substantially perpendicular to the tread 2' of the pedal body 2, with the cleat 30 defining cam surfaces 20d at opposite sides at rear positions thereof which are inclined to converge downwardly. This construction corresponds to the second embodiment in function and effect. While the cam surfaces 20d are provided on the rear rotation restrictors 20c in the second embodiment, the cam surfaces 20d may be formed on the front rotation restrictors 20b only or may be formed on both the front rotation restrictors 20b and the rear rotation restrictors 20c. In the former the second imaginary axis X is located rearwardly of the cleat 30, while in the latter the position of axis X variable with the way a couple of forces is applied to the cleat 30. In the former case, the relationship between the semicircular top 30c and the second pressing edge 3f and second pressed edge 5f may be reversed fore and aft from their relationship in the first embodiment. In this embodiment, the front and rear rotation restrictors 20b and 20c are distributed right and left of the pedal body 2. However, the rotation restrictors may be provided only at one front position and one rear position of the pedal body 2. Further, the rotation restrictors 20c and 20d may be provided centrally of the pedal body 2 instead of the two positions at the front and rear thereof. Also only one cam surface may be provided on the pedal body 2 instead of two.

Claims: A pedal for engaging a cleat comprising: a front cleat hook (4); a rear cleat hook (5); wherein at least one of said front (4) and rear hook (5) is pivotably supported by said pedal, urging means (6) for urging said at least one of said hooks toward an engaging position; a cleat contact plate (20) positioned between said front and rear cleat hooks; cleat-movement restricting means (20b); characterized in that said cleat-movement restricting means (20b) is provided adjacent to said front cleat hook (4), said restricting means having a pair of stopper projections (20a) that are spaced apart from each other, and that said pair of stopper projections (20a) are formed by bending portions of said contact plate (20) substantially vertically therefrom in a neighboring region of said front cleat hook (4).

Inventors: NAGANO MASASHI, NAGANO, MASASHI
Applicants: SHIMANO INDUSTRIAL CO, SHIMANO INDUSTRIAL COMPANY LIMITED
Application year: 1990
Main classification: B62M3
IPC codes: B62M3