Combined shoe and pedal for sports bicycle

A plurality of retaining pins extending laterally outwardly from the side edges of a sole of a bicyclist's shoe engage in conjugate holes formed in inner and outer spring-loaded retaining plates which extend vertically upwardly from a pedal, thereby securing the shoe to the pedal. The inner retaining plate is laterally movable away from the outer retaining plate by shifting the shoe inwardly, thereby enabling the shoe to be engaged and disengaged from the pedal. The outer retaining plate may be depressed by the shoe and automatically latched into a retracted position inside the pedal body so that the shoe may be secured to the pedal by only the inner retaining plate or may be disengaged completely. The outer retaining plate may be unlatched and released to return to upper position concurrently with movement of the inner retaining plate away from the outer retaining plate.

BACKGROUND OF THE INVENTION 
The present invention generally relates to the art of sports bicycles, and 
more specifically to a novel and unique strapless shoe and pedal assembly 
for detachably locking a bicyclist's shoes to the pedals of the bicycle. 
The art has long recognized the desirability of increasing the period 
during which a rider can apply effective force to the pedals of a bicycle. 
When utilizing a conventional bicycle pedal, the rider is only able to 
exert a driving force during an arc of pedal movement of less than 180 
degrees for each complete revolution of the crank axle; and maximum 
driving force is exerted only through an arc of something less than about 
90 degrees. 
To increase the period during which the propelling force is applied, the 
art has proposed various means for positvely attaching the bicyclist's 
shoes to the pedals so as to enable the rider to develop work, or exert 
cranking force, on the upstroke as well as on the downstroke of each pedal 
cycle. Thus, while progressing through the downstroke of one pedal, the 
cyclist is able to apply cooperating force on the other pedal through its 
upstroke. 
While it is highly desirable to lock, or secure, the shoes to the pedals 
for road and racing bicycles, such a system is equally advantageous for 
mountaineering bicycles used to climb steep hills and traverse rough 
terrain where loss of positive shoe to pedal contact, or engagement, not 
only reduces driving force, but also may result in serious injury to the 
rider. 
Numerous devices have been proposed for accomplishing this desirable rigid 
securement. Included, for example, are strap and/or clip arrangements 
which are attached to the pedal and extend over the top of the shoe and 
sometimes the instep of the rider's shoes. Although such devices have the 
advantage of being useful regardless of the kind of shoe worn by the 
rider, they have an undesirable aspect in that they tend to dig 
uncomfortably into the upper portions of the rider's feet and can also 
disengage from the pedal under disadvantageous circumstances. 
The current industry standard expedient to overcome the disadvantages of 
the prior art is the "Look" system, developed by Look America, Inc. of 
Highland Park, Ill. The system is evolved from the art of ski bindings and 
in general comprises a cleat fixed to the bottom of each shoe and a cleat 
retention mechanism integral with each pedal. The cleat retention 
mechanism comprises a fixed rear cleat retention plate and a spring loaded 
front cleat retention plate which lock onto the shoe cleat when the rider 
steps down onto the pedal. 
Further examples of downwardly extending cleats and retaining arrangements 
are disclosed in U.S. Pat. No. 550,409, issued Nov. 26, 1985 to Hanson and 
U.S. Pat. No. 4,298,210, issued Nov. 3, 1981 to Lotteau et al. These 
latter systems feature bayonet locking arrangements whereby the rider 
steps down on the pedal and then rotates his foot through an angle to make 
the connection. 
The Look system is satisfactory for racing and other applications in which 
the rider will not be expected to dismount from the bicycle and walk for 
any significant distance. However, walking on shoes with cleats attached 
is extremely uncomfortable, and the cleats will become damaged quickly if 
subjected to such abuse. For this reason, a retaining arrangement 
including sole mounted cleats is unacceptable for mountaineering bicycle 
applications wherein the rider must dismount from time to time and push or 
carry the bicycle over rough terrain. 
Various arrangements which do not include sole-mounted cleats are found in 
the prior art. U.S. Pat. No. 575,712, issued Jan. 26, 1897 to Hamilton et 
al., U.S. Pat. No. 620,266, issued Feb. 28, 1899 to Wodiska and U.S. Pat. 
No. 616,167, issued Dec. 20, 1898 to Walker, disclose mechanical devices 
which are arranged to clamp over or retain the side edges of the soles of 
the rider's shoes. More specifically, these systems comprise clamps or 
lips which are moved through linkage or cam mechanisms inwardly into 
clamping engagement with the shoe when the rider steps downwardly onto the 
pedals. 
Although of considerable utility, these devices are not designed for use 
with modern cycling shoes made of lightweight materials since they tend to 
dig into and rapidly damage such materials. These devices are further 
unacceptable for mountaineering bicycle applications as constant downward 
pressure on the pedals is required for the linkage mechanisms to affect 
lateral clamping of the shoes, and such downward pressure is essentially 
lacking during upward movement of the pedals while the bicycle is climbing 
a steep hill. 
A major drawback of all retention systems known heretofore is that none of 
them includes a provision for disengaging the retention mechanism for 
conventional operation as non-retaining pedals without disassembly of the 
entire retention mechanism. 
It is therefore an object of the present invention to provide a combined 
shoe and strapless pedal for a sports bicycle which securely retains the 
rider's shoes to the pedals without the expedient of downwardly extending 
cleats mounted on the soles of the shoes. 
It is a further object of the present invention to provide a road pedal 
assembly which eliminates the discomfort associated with prior art strap 
and clamp retention arrangements. 
It is a further object of the present invention to provide a road pedal 
assembly which enables the retention mechanism to be partially or entirely 
disengaged with minimal effort. 
Other objects, together with the foregoing, are attained in the embodiments 
described in the following description and illustrated in the accompanying 
drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
While the combined shoe and strapless pedal assembly of the present 
invention is susceptible of numerous physical embodiments, depending upon 
the environment and requirements of use, substantial numbers of the herein 
shown and described embodiments have been made, tested and used, and all 
have performed in an eminently satisfactory manner. 
Referring particularly to FIGS. 1 to 3 of the drawing, a combined shoe and 
strapless road pedal assembly for a sports bicycle embodying the present 
invention is generally designated by the reference numeral 10 and is 
designed securely but releasably to retain shoes 12 worn by a rider or 
operator of the bicycle (not shown) to pedal bodies 14. The pedal bodies 
14 are mounted for rotation about the transverse axis 19 of pedal shafts 
16, or spindles which extend from crank arms 18 of a crank shaft 20 
journaled on the frame of the bicycle in a conventional manner. Each pedal 
body includes an inner end 11, an outer end 13, a leading edge 15 and a 
trailing edge 17. 
The present pedal assembly 10 comprises inner retaining means in the form 
of protrusions which are illustrated as being a pair of pins 22 which 
extend laterally inwardly toward the central vertical plane 23 of the 
bicycle from the metatarsal, or widest transverse, region 24 of the inner 
side edges 25 of the soles 26 of shoes 12. 
Outer retaining means or pins 28 extend laterally outwardly from the outer 
side edges 29 of the soles 26 in a manner identical to the pins 22 but in 
the opposite direction. 
The pedal assembly 10 further comprises an upstanding inner retaining plate 
30 formed with a spaced pair of apertures 32 (see FIG. 2). In an 
essentially similar manner, an upstanding outer retaining plate 34 is 
formed with a spaced pair of holes 36 (see FIG. 3). 
In shoe-engaging position, as illustrated in FIGS. 1 to 3, the retaining 
plates 30 and 34 extend upwardly from the pedal bodies 14 and engage the 
respective lateral, or side edges 25 and 29 of the soles 26 of the shoes 
12 in such a manner that the pairs of pins 22 and 28 are disposed in the 
pairs of holes 32 and 36 respectively, which are conjugate thereto. The 
shoes 12 are thereby securely locked to the pedal bodies 14. 
The steps of engaging and disengaging the shoes from the pedals are readily 
performed. 
As illustrated in FIGS. 4 to 6, each inner retaining plate 30 is mounted on 
the respective pedal body 14 for lateral movement between fully engaged 
position, illustrated in FIG. 4, and a partially engaged position, 
illustrated in FIG. 5. In partially engaged position, the inner retaining 
plate 30 is spaced farther away from the outer retaining plate 34 than in 
the fully engaged position. The inner retaining plate 30 is spring-biased 
toward the fully engaged position, as will subsequently be described in 
detail, but may be moved to a partially engaged position against the 
spring force by shifting the shoe 12 laterally inwardly (toward the left 
in FIGS. 4 and 5). 
The (left) shoe 12 is illustrated as being securely retained by the pedal 
assembly 10 in FIG. 4 with the conjugate pins and holes in full 
engagement. 
To release the shoe 12 from the pedal body 14, the rider first moves the 
shoe 12 inwardly (leftwardly) as illustrated by directional arrow 27 in 
FIG. 5, thereby moving the inner retaining plate 30 against spring-bias 
into partially disengaged position in which the outer pins 28 are 
retracted and disengaged from the respective outer holes 36. The rider 
then rotates the (left) shoe 12 counterclockwise, as indicated by the 
directional arrow 37 in FIG. 5, so that the pins 28 completely clear the 
outer retaining plate 34. The shoe 12 can then be moved ouwardly 
(rightwardly) as viewed in FIG. 6 to disengage the inner pins 22 from the 
holes 32 in the inner retaining plate 30 and thereby entirely disengage 
the shoe 12 from the pedal body 14. 
The procedure is reversed for engaging and retaining the shoe 12 in the 
pedal body 14 and will not be described in detail as such should be 
readily apparent from the above description. 
In accordance with an important feature of the present invention as 
illustrated in FIGS. 7 and 8, the outer retaining plate 34 is 
spring-biased toward an upper, pin-engaging position, as illustrated in 
FIG. 7, but may be moved into a lower position, illustrated in FIG. 8, in 
which the outer retaining plate 34 is retracted inside the pedal body 14. 
This is accomplished by merely depressing the top surface of the outer 
retaining plate 34 with the sole 26 of the shoe 12, as illustrated by the 
downwardly pointing arrow in FIG. 7. 
The outer retaining plate 34 will be latched in the lowered, retracted 
position by a latch mechanism which will subsequently be described in 
detail, enabling the shoe 12 to be retained in a partially engaged mode, 
as illustrated in FIG. 8, in which only the inner pins 22 are engaged in 
the holes 32 in the inner retaining plate 30. 
Although not shown, it is further possible to shift the shoe 12 farther 
outwardly from the position shown in FIG. 8 so that the pins 22 are fully 
disengaged from the holes 32 and the pedal assembly is operable in a 
conventional, non-retained mode. 
As will also be described in detail, the inner retaining plate 30 is 
connected to the latch mechanism of the outer retaining plate 34 in such a 
manner that lateral movement of the inner retaining plate 30 from the 
partially engaged position shown in FIG. 8 toward the left will cause 
release of the latch mechanism and enable the outer retaining plate 34 to 
move upwardly from the retracted position shown in FIG. 8 to the projected 
position shown in FIG. 7. Upon reaching upwardly projected position, the 
outer retaining plate 34, is prepared to re-engage the outer pins 28 as 
the rider shifts the shoe 12 outwardly. The spring-bias on the inner 
retainer plate 30 maintains engagement with the inner pins 22. 
FIGS. 9 to 15 illustrate the detailed construction of the present strapless 
pedal assembly. Although FIGS. 9 to 15 show the left pedal it will be 
noted that the right pedal is a mirror image thereof. 
The pedal body 14 comprises a pedal block 38 journaled on the spindle 16 
(see FIGS. 13 and 14) and an outer plate 40, or outer rim, which is 
fastened to the pedal block 38 by any appropriate means such as screws, 
bolts, welding or adhesive. 
The pedal block 38 and the rim plate 40 define an inner pair of transverse 
channels 42 (see FIGS. 9 and 11) in which portions of the inner retaining 
plate 30 are slidably received for lateral, or transverse movement of the 
inner plate 30 between engaged and disengaged positions. 
The pedal block 38 and the rim plate 40 further define a channel 44 (see 
FIGS. 10, 11 and 13) for slidably receiving the outer retaining plate 34 
for vertical movement of the outer plate 34 between engaged and disengaged 
positions thereof. 
The pedal block 38 includes an upper surface 35 and a lower surface 43. The 
upper surface 35, along with portions of the plates, receive the work 
effort exerted by the rider and transmit the force to the spindle 16 and 
crank. 
As can best be seen in FIG. 9, the inner retaining plate 30 is formed with 
bifurcations 31 which extend outwardly. A pair of rails 66 (see FIGS. 9 
and 11) fixed to the pedal block 38 transversely spans the pair of 
transverse channels 42 and extends through a pair of transverse holes 33 
formed through the respective bifurcations 31, thereby guiding the inner 
retaining plate 30 for smooth lateral movement. 
As best seen in FIGS. 9, 10 and 14, a pair of aligned fore and aft rods 46 
is rigidly fitted in the block 38. The rods 46 include free ends 47 which 
extend into a pair of open or cutout portions 39 of the pedal block 38. 
Fore and aft aligned pins 48 (see FIGS. 9 and 10) are fixed to opposite 
ends of the inner retaining plate 30; and biasing means in the form of 
tension springs 50 are connected between the respective ends 47 of the 
rods and the pins 48 and thereby urge the inner retaining plate 30 in a 
right hand direction as viewed in FIGS. 9 and 10 toward an engaged 
position. The ends of the pins 48 protrude through transversely elongated 
apertures 45 in the pedal block (see FIG. 10). 
As further illustrated in FIGS. 9 and 11, the pedal block 38 is formed with 
a pair of central open or cutout portions 41 through which the central 
portion of each of the rods 46 extends. Biasing means in the form of 
compression springs 51 are retained between a pair of blind holes 52 (see 
FIG. 15) formed in the lower surfaces of two spaced arms 49 projecting 
inwardly from the outer retaining plate 34 and a pair of spring seats 53 
extending upwardly from an adjacent upper surface of a bottom plate 54 
mounted by screws 55 to the bottom 43 of the pedal block 38. The springs 
51 urge the outer plate 34 upwardly toward the engaged position as 
illustrated in FIGS. 11 and 13. 
A fore and aft rod 56 rigidly extends through the two transverse arms 49 of 
the outer retaining plate 34 and a bifurcated link 58, or yoke, is 
pivotally connected at its opposite ends to the adjacent ends of the two 
rods 46 and to the central portion of the rod 56, thereby guiding the 
outer retaining plate 34 for substantially vertical pivoted movement. The 
channel 44 is provided with sufficient clearance to accommodate the small 
amount of lateral movement introduced by rotation of the link 58. As an 
alternative as appears most clearly in FIGS. 11 and 13, an arcuate strip 
57 of anti-friction material can be used in which case the pivoted 
connections of the link 58 are made loose enough to accommodate the right 
lateral movement caused by rotation of the link. 
As best seen in FIGS. 11 and 12, latch means 59 for releasably latching the 
outer retaining plate 34 in the lower, or disengaged, position comprises a 
pair of latch arms 60 on vertical mounting plates 64, mounted on the 
bottom plate 54, by respective pivotally supported pivot pins 61. A pair 
of latch pins 62 is integrally fixed to the inner ends of the arms 49 on 
the outer retaining plate 34. The latch arms 60 are normally urged 
clockwise as viewed in FIG. 11 by biasing means, which will be described 
in detail hereinbelow, toward the outer retaining plate 34 and thus into 
latching engagement with the latch pins 62. 
More specifically, downward movement of the outer retaining plate 34 causes 
the lower sloping portions of the latch pins 62 to cam aside the conjugate 
upper sloping surfaces of the catch portions 63 of the latch arms 60 until 
clear, at which juncture the latch arms 60 return to upright attitude with 
the latch portions 63 overlying the latch pins 62. In this manner, 
subsequent upward movement of the outer retaining plate 34 is prevented by 
engagement of the latch pins 62 with the overlying catch portions 63. 
The present assembly 10 further comprises means for releasing the latch 
mechanism 59 including a pair of rigid transversely oriented connecting 
rods 68 which may be formed from a piece of stiff wire. Leftward movement 
of the connecting rods 68, as viewed in FIG. 11, causes counterclockwise 
rotation of the latch arms 60, thereby releasing the latch pins 62 and 
allowing the outer retaining plate 34 to move upwardly to upper engaged 
position under urgency of the compressive springs 51. 
The release means further comprises a pair of first engaging members 70 
rigidly fixed to the ends of the connecting rods 68 adjacent the inner 
retaining plate 30. A pair of second engaging members 72 is integrally 
formed as a portion of the inner retaining plate 30. The second engaging 
members 72 are each formed with a transverse aperture 73, or hole, through 
which the connecting rod 68 slidably extends and an engaging surface 74 
which is abuttable with the adjacent first engaging member 70 when the 
inner retaining plate 30 is translated inwardly (toward the left in FIG. 
11). 
A small post 76 is fixed to the bifurcation arm 31 of the plate 30, as best 
seen in FIG. 12. A wire torsion spring 78 is coiled around the post 76. 
One end of the spring wire is anchored in a hole 77 formed in the 
bifurcation arm 31 of the inner retaining plate 30. The other end of the 
torsion spring 78 engages the left side of the first engaging member 70, 
as viewed in FIGS. 11 and 12. The spring 78 exerts a rightward force on 
the first engaging member 70 and thereby the connecting rod 68 which 
provides the biasing force heretofore described, urging the latch arm 60 
rightwardly and clockwise toward latching engagement with the latch pin 
62. 
Initial leftward movement of the inner retaining plate 30, as viewed in 
FIGS. 11 and 12, has no effect on the latch mechanism because the engaging 
members 70 and 72 remain disengaged. In other words, it is necessary for 
the inner retaining plate 30 to move to the left through a predetermined 
distance, equal to the initial spacing between the first engaging member 
70 and the engaging surface 74 when the inner retaining plate 30 is in 
engaged (rightmost) position, before abutment of the engaging surface 74 
with the first engaging member 70 can occur. However, further leftward 
movement of the inner retaining plate 30 and accompanying second engaging 
member 72 toward disengaged position causes the first engaging member 70 
and thereby the connecting rod 68 and latch arm 60 to move leftwardly for 
release of the latch pin 62 and consequent upward movement of the outer 
retaining plate 34 to fully elevated position. 
Although a specific and preferred embodiment of the present invention has 
been described in detail, the invention is not so limited. Various 
modifications, such as eliminating the bifurcated link 58 and allowing the 
outer retaining plate 34 to be guided for upward and downward movement by 
the channel 44 alone will become readily apparent to those of skill in the 
art. A further modification would be to replace the latch release 
mechanism disclosed herein with a spring connected directly to the latch 
arm 60; and to replace the connecting rod 68 and engaging members 70 and 
72 with a flexible wire or cord. In such a case, the spacing between the 
engaging members 70 and 72 in the illustrated embodiment could be 
duplicated by means of a predetermined amount of slack in the wire or 
cord. As yet a further modification, the retaining means which have been 
described as conjugate pins and holes formed on the sides of the sole of 
the shoe and in the vertical retaining plates respectively may be replaced 
with any other configuration which will provide an equivalent function, 
such as elongated ridges formed in the sides of the sole and elongated 
claws or clamps conjugate to the ridges for retaining engagement therein. 
Various other modifications will become possible for those skilled in the 
art after receiving the teachings of the present disclosure without 
departing from the teachings thereof.