WO1986004489A1

WO1986004489A1 - Improvements in replaceable shoe soles

Info

Publication number: WO1986004489A1
Application number: PCT/US1985/001131
Authority: WO
Inventors: Jack J. Saffron; Mark V. Goodyear
Original assignee: Jack Saffron Sports Inc.
Priority date: 1985-02-11
Filing date: 1985-06-14
Publication date: 1986-08-14
Also published as: AU4607585A; EP0214992A1

Abstract

A replaceable shoe sole for athletic shoes, work shoes, casual shoes, and the like, utilizes a ridge/groove interconnection to permit the replacement of the sole in the event of wear or damage. The ridge, which is undercut, mates with the groove of a corresponding cross-sectional configuration to provide the retention force necessary to maintain the replaceable shoe sole in position adjacent the mid-sole of the shoe. Certain improvements comprise the use of projections and matching cavities adjacent the ridge/groove interconnection to provide additional retention force against lateral and twisting stresses which are placed upon the replaceable shoe sole during use. In addition, the groove is provided with a starting area in order to facilitate the attachment and replacement of the sole. Also disclosed is a replaceable toe which is attached by means of a similar ridge/groove interconnection, and a clamping device for providing additional retentivity.

Description

IMPROVEMENTS IN REPLACEABLE SHOE SOLES

Background of the Invention

The present invention relates to improvements in shoe soles and, more particularly, improvements in replaceable shoe soles for athletic shoes.

Over the past decade, there has been a marked upsurge in the sale of athletic shoes, such as shoes for the use in the sports of running or jogging, tennis, aerobics, golf, etc. This upsurge has been generated by a number of factors. First, the general population has become much more health conscious than in previous decades which has resulted in greater participation in athletics and exercise activity. In particular, running and jogging have become common activities for men, women and children of all ages.

Secondly, modern athletic shoes are constructed so as to be extremely comfortable and to provide a large degree of support for those portions of the foot and ankle which experience great stress while participating in certain sports. This improvement in the construction of the athletic shoes has encouraged participation in athletics and exercise by many participants. Similarly, specialized athletic shoes have also been constructed for use in particular sports. For example, one can easily find shoes which have been specially constructed and engineered for use in sprinting, jogging, basketball, racquetball, soccer, etc.

Thirdly, modern athletic shoes have also become casual shoes and are commonplace in non-athletic situations. They are frequently worn in many styles and colors, and have become a fashion item as well as a practical athletic item. Finally, many retail stores have been opened which specialize in the sale of athletic shoes.

All of these factors have led to a large upsurge in the sale of athletic shoes and an increase in interest in them. As mentioned above, manufacturers of athletic shoes have constantly improved their quality so that the shoes will be more comfortable and durable. At the same time, however, the cost of good athletic shoes has risen to as high as $50.00 or more. The upper portions of the shoes are frequently constructed from leather or other durable materials and are assembled so as to be resistant to rips and tears. However, with frequent use, the soles of the shoes will often wear out much faster than the upper portion of the shoe. This is because, naturally, the sole of the shoe is subject to more destructive and other forces than the upper portion of the shoe. Certain improvements in athletic shoe soles have been devised in which the worn sole of the shoe can be replaced with a new one by securely attaching It to the upper portion of the shoe. However, it has been found desirable to enhance the construction and operation of such replaceable shoe soles to provide even better performance.

Existing shoes with replaceable soles typically are comprised of an upper shoe portion, or "upper", having a bottom surface or "mid-sole". A replaceable sole is provided with a substantially continuous ridge which is snapped or press fitted into a matching, deformably resilient groove recessed into the mid-sole. The ridge is comprised of a leading edge portion or head which is undercut to form a narrower neck. The neck attaches the ridge to the upper surface of the replaceable shoe sole. The groove recessed into the mid-sole is also substantially continuous and has a cross-sectional shape generally the same as that of the ridge. The width of the opening of the groove Is approximately the same as the width of the neck of the ridge. The opening is formed by a pair of protrusions which are resilient and deformable such that they permit the head of the ridge to pass through the opening and yet are sufficiently rigid to act as retention means for the ridge. These protrusions cooperate with the undercut portions of the ridge to hold

e "s_<_- sr- -TTsT UTE SH&ET the replaceable shoe sole firmly in place while the wearer of the shoe participates in various athletic and non- athletic activities.

It has been found in certain sports activities that considerable stress is exerted upon the shoe, and particularly the sole. The extreme frictional forces may be imparted to the sole depending on the weight and speed of the wearer. These forces are, in turn, transmitted to the ridged groove interconnection holding the sole in place on the mid-sole. Furthermore, in particular sports, other torques and twisting motions are exerted on the sole. For example, in tennis, fast stops, lateral movement, and the twisting motion of the serve put a great deal of stress upon the area of the shoe which corresponds to the ball of the foot. This ball area of the shoe often carries the greatest weight of the user so that the highest stresses and forces become concentrated on this portion of the shoe. The ball of the shoe also tends to be an axis for rotational or twisting movement.

As the weight of the user shifts forward and backward, the weight is concentrated along the length of the sole, including the center section of the sole. Thus, additional, concentrated forces and stresses are placed upon the sole at both the ball or toe portion and the center section. In golf, on the other hand, the twisting action normally followed by a golfer places a torque on the heel of the shoe. It has also been found that in certain sports, such as tennis, the toe of the shoe wears out much faster than other portions of the sole.

In the manufacture of athletic shoes with replaceable shoe soles, it has been found that the matching shape of the ridge and groove involves a compromise or a trade¬ off. With a large undercut formed on the ridge, a great deal of retentive strength is maintained within the groove. On the other hand, the replaceable shoe sole is difficult to assemble and remove. With a smaller undercut, the parts are easily assembled but their retention force is less .

While the matching ridge and groove combination described above provides good retention for a replaceable shoe sole, it is difficult to make the replacement by manually press fitting the ridge into the groove. Accordingly, a need has arisen for certain improvements in replaceable shoe soles for athletic shoes, as well as other casual, walking and work shoes.

Summary of the Invention

The present invention comprises improvements in replaceable shoe soles for athletic shoes, walking shoes, work shoes, and the like. In order to withstand the stresses and twisting forces applied on these shoes, and particularly athletic shoes, the present invention comprises a projection formed on the upper surface of the replaceable shoe sole which removably mates with a cavity formed in the mid-sole. This configuration is designed to permit the shoe to withstand lateral and twisting forces, rather than mere removal forces which would cause the ridge to be removed from the groove.

Preferably, these projections and mating cavities can be placed in the ball area of the shoe where the sole may experience the greatest stresses. A similar projection may also be placed at the heel for use in sports such as golf where the twisting action of the golf shoe places particular stress at that location. In addition, the projection and mating cavities can also be placed in the center section of the shoe in order to provide additional support. Since retention of the replaceable sole on the mid-sole is accomplished by means of a ridge and groove, the fit between the projection and cavity need not be one of close tolerance. The projection may be undercut slightly in order to provide good retention means within the cavity and to prevent any shifting. In the heel projection, the bending of the shoe causes a distortion in

its length. In other words, the bending of the shoe, generally in the center section, causes the projection to follow a radius which is longer than its corresponding cavity. Accordingly, the heel projection is constructed so as to be slightly shorter than the length of the matching cavity to accommodate this elongation.

Alternatively, the thickness of the replaceable shoe sole in its center portion can be reduced so that, during bending, the stretching or elongation will occur in this portion and will not occur at the heel. This will maintain the dimensional integrity of the projections at both the toe and the heel while still accommodating changes in dimension at the center portion of the sole.

These projections distribute the stresses and twisting forces so that they are not borne alone by the ridge/groove interconnection. These forces are concentrated largely on the ball and heel sections of the sole, but also are experienced in the center section as the weight of the user is shifted back and forth. Because these forces act on the sole in essentially a horizontal direction, resulting from lateral movement of the wearer, no tight interconnection between the projection in the cavity is required thus facilitating the assembly of the sole to the mid-sole and its subsequent removal for replacement purposes. Accordingly, these projections greatly increase the retention capability of the removable sole.

In order to facilitate the insertion of the ridge into the groove, the present invention also comprises a starting area for this replacement. In this aspect of the present invention, one or both sides of the groove in a limited area are removed. In other words, one or both of the projections which form the opening of the groove are removed for a short distance so that the groove opening is widened. In addition, arrows or other small indication means are placed on the side of the mid-sole indicating where this shaved portion is located. Thus, it is easier to start the insertion of the ridge in the groove in this starting area as indicated by the arrows. Once the ridge is inserted into the groove in this starting area, the insertion of the remaining portion of the ridge around the circumference of the shoe is greatly facilitated. This is because insertion of a portion of the ridge causes the opening in the groove to enlarge in the area immediately adjacent the starting area. Thus, the insertion in the adjacent area is also facilitated and the process can be continued around the circumference of the shoe. This process, also referred to as "walking", provides a method for the step-by-step insertion of the ridge into the groove. In this method of attaching the replaceable shoe sole to the mid-sole, finger pressure is sufficient to manually press-fit the ridge into the matching groove.

The present invention also comprises a replaceable toe for athletic shoes where extraordinary wear and tear is experienced at this location of the shoe. This is sometimes due to toe dragging which occurs in the particular activities, such as serving in tennis. The replaceable toe of the present invention is also maintained in place by means of a ridge or other projection on the inner surface of the replaceable toe which mates into a groove or other indentation in the toe of the shoe. The ridge and groove combination of the replaceable toe need not have the same kind of retention capabilities as the sole because of fewer frictional and moment forces acting on the toe. The replaceable toe can also be provided with a lower flange which overlaps the replaceable shoe sole, thus assisting in maintaining its position on the mid-sole of the shoe.

The concepts and principles of the present invention also comprise a snow travelling device which can be utilized as a snow shoe or, alternatively, a cross-country type ski. In this device, the bottom surface of a boot or other shoe is provided with a groove similar in construction and configuration to the groove described above. A base member is likewise provided with a matching ridge for attachment to the sole of the boot. This base member can be provided with attachments, such as snow shoe webbing, or cross-country ski devices, in order to permit its use as a snow travelling device. The base member is provided with a flexible or hinged heel which permits the heel lifting action utilized in walking or travelling in snow shoes or cross-country skis. This flexible heel acts as a hinged binding.

Description of the Drawings

FIGURE 1 is a perspective view illustrating the bottom of a shoe having a mid-sole in which are formed a peripheral groove as well as several cavities for retaining a replaceable sole.

FIGURE 2 is a perspective view of the replaceable shoe sole of the present invention illustrating on the top surface thereof the ridge which mates with the groove of the mid-sole and a ball projection which mates with the corresponding cavity thereof.

FIGURE 3 is a partial cross-sectional view illustrating the ridge/groove interconnection.

FIGURE 4 is a perspective view of a shoe having a replaceable shoe sole mounted on the mid-sole thereof, with the sole partially cut away to reveal the cavities and the projections.

FIGURE 5 is a perspective view of a replaceable shoe sole showing the top surface thereof and illustrating ball, center, and heel projections.

FIGURE 6 is a perspective view of a shoe with a replaceable shoe sole having golf cleats mounted on the bottom surface thereof.

FIGURE 7 is a partial cross-sectional view illustrating a ball projection inserted within a corresponding cavity formed on the mid-sole. FIGURE 8 is a partial cross-sectional view illustrating the heel projection which is shorter in length than its matching cavity.

FIGURE 8a is a perspective view in partial cross section illustrating the starting area for facilitating insertion of the ridge in the groove.

FIGURE 9 illustrates a shoe in phantom having a replaceable toe.

FIGURE 10 is an exploded cross-sectional view taken along lines 10-10 of FIGURE 9 illustrating the replaceable toe which is mounted by means of a ridge removably inserted into a groove on the toe of the shoe.

FIGURE 11 is a cross-sectional view of the replaceable toe of the present invention illustrating one embodiment in which it overlaps the replaceable shoe sole.

FIGURE 12 is a cross-sectional view of an alternate replaceable toe.

FIGURE 13 is a perspective view of a base plate for a snow shoe device having a flexible heel to permit use of the device as a snow shoe or cross-country ski.

FIGURE 14 is an exploded, perspective view of a shoe or boot which is used in connection with the base plate of FIGURE 13, illustrating a device for clamping the groove of the mid-sole onto the ridge.

FIGURE 15 is a side, partial cross-sectional view of the base plate and shoe of FIGURES 13 and 14.

Detailed Description of the Invention

FIGURE 1 illustrates the bottom surface 10 of a mid- sole 12 of a shoe 14. The shoe may be an athletic shoe for participation in any number of sports, or may be a boot, a walking shoe, a work shoe, and the like. The principles of the present invention apply equally to a wide variety of such shoes.

The mid-sole 12 of the shoe is provided with a substantially circumferential or peripheral groove 16 which is formed therein. The groove 16 is primarily longitudinal and is located near the periphery of the mid- sole 12. Also formed in the mid-sole 12 is one or more cavities, such as the cavity shown near the ball or toe of the shoe ("ball cavity 18"), the cavity in the center section of the mid-sole 12 ("center cavity 20") and the cavity near the heel ("heel cavity 22").

FIGURE 2 illustrates the top surface 24 of a replaceable shoe sole 26 having a ridge 28 formed thereon in substantially the same configuration as the groove 16 of the mid-sole 12. Also shown on the top surface 24 of the sole 26 is a ball projection 29 which has substantially the same configuration as the matching ball cavity 18 formed in the mid-sole. The ball projection 29 is located toward the toe of the sole where the greatest weight of the wearer is concentrated. The precise location of the ball projection 29 will vary with the sport, but may correspond to the ball or toe of the foot. If.desired, similar projections 30 and 32 can be formed in the center of the sole and near the heel, as shown in FIGURE 5, to match the center and heel cavities 20 and 22, respectively, of the mid-sole 12.

The replaceable shoe sole 26 of the present invention is attached to the mid-sole 12 by means of the ridge/groove interconnection illustrated in FIGURE 3. This figure illustrates, in cross section, the ridge 28 inserted into the groove 16 of matching configuration. The ridge is provided with a beveled leading edge 27 to facilitate insertion into the opinion 38 of the groove 16. As illustrated, the ridge 28 is undercut so as to form a relatively large head 34 attached to the top surface 24 of the sole 26 by means of a relatively narrower neck 36. Likewise, the groove 16 is provided with a narrow opening 38 formed by means of protrusions 40 on either side. By forcing or press fitting the head 34 of the ridge 28 through the opening 38 and into the groove 16, a retentive force is created which resists forces tending to remove the sole from the mid-sole. This retentive force is supplied by the relative rigidity of the protrusions 40 which form the groove opening 38 and their positioning adjacent the undercut head^'34 of the ridge 28. However, by exerting a sufficient removal force, the ridge 28 can be removed so that the sole 26 can be replaced.

Thus, the bottom surface 41 of the replaceable sole can be provided with traction devices 42, such as those shown in FIGURE 4, or with the cleats, such as the golf cleats 44 shown in FIGURE 6, to provide a very versatile shoe with interchangeable soles. In addition, when these soles 26 become worn, they can be easily replaced.

It has been found that the ridge/groove interconnection illustrated in FIGURE 3 is sufficient to firmly retain the replaceable shoe sole 26 on the mid-sole 12 under most conditions. Such conditions include the removal forces acting substantially vertical to the ground. However, it has also been found that a certain lateral or twisting forces which are exerted on the sole can also cause it to wholly or partially become removed from the groove. For example, in sports such as tennis and racquetball, lateral motion is very common. During such lateral motion, the weight of the body of the wearer is shifted from side to side so that all the holding or retentive strength of the sole must be supplied by one of the longitudinal edges 43 (FIGURES 1&2) of the ridge/groove interconnection. This is because the opposite edge may be lifted from the ground or may be carrying very little weight. Under these conditions, the neck 36 and head 34 of the ridge 28 may elongate due to this lateral stress, and the protrusions 40 forming the opening 38 of the groove 16 may become distorted outwardly, thus causing the opening to widen. Thus, the ridge 28 tends to be removed from the groove 16 and interconnection is lost. Furthermore, in sports such as golf, the toe or heel portion of the shoe is twisted, thus, exerting a torque or twisting force on the sole. Again, all of the holding force must be supplied by one concentrated area of the ridge/groove interconnection.

Thus, the projection/cavity interconnection 39 of the present invention shown in FIGURE 4, provides additional retentive force to withstand these lateral and twisting forces. The projection/cavity 39 interaction causes the lateral forces to be distributed more broadly across the sole/mid-sole interface. Thus, the ridge/groove interconnection sees less of the lateral forces, ensuring the retention of the mid-sole.

FIGURES 7 and 8 illustrate a partial cross-sectional configuration of the ball projection 29 and the heel projection 32, respectively. Referring first to FIGURE 7, the ball projection 29 is preferably undercut slightly so as to provide a snug fit within the corresponding cavity 18 on the mid-sole 12. However, this interconnection does not provide the same kind of retentive force against substantially vertical removal forces as does the ridge/groove interconnection described above. The purpose of the projection/cavity interconnection is to provide additional resistance to lateral and twisting forces and to maintain the ridge 28 firmly in position within the groove 16. Alternately, the projection 29 need not be undercut. The ball projection 29 is rounded slightly in the direction of the toe so as to distribute the holding force more broadly in that area.

FIGURE 8 illustrates in partial cross-section the projection/cavity interconnection near the heel of the replaceable sole 26 while the sole is experiencing bending, usually at the center section. As illustrated, the heel projection 32 is preferably slightly shorter than its corresponding cavity 22. The bending of the sole 26 causes the heel projection 32 to elongate and move in the direction of the arrow because of the larger radius it experiences. Thus, allowance must be made in the cavity 22 to provide for this elongation. The purpose of the heel projection 32 is to resist removal forces that are caused by lateral or twisting forces. The heel projection is generally rectangular to conform with the shape of the heel, permitting it to distribute its retentive force over a wide area at the heel.

FIGURE 8a is a partial cross-sectional view illustrating a portion of the groove in which the protrusions on both sides have been removed. This cross- section refers to a starting area 46 indicated in FIGURE 4 for facilitating insertion of the ridge 28 within the groove 16. As shown, the protrusions 40 which form the opening 38 of the groove 16 are shaved or beveled for a short distance on their upper surfaces to widen the opening 38. By providing this starting area 46, the head 34 of the ridge 28 is easily inserted into the groove 16 since it does not have to be forced in the small opening 38 between two protrusions 40. Alternatively, only a single protrusion 40 in the starting location 46 can be shaved slightly to permit insertion of the ridge 28. Preferably, the starting location 46 is found in the center section of the mid-sole 12 since this section sees a minimum amount of removal for us.

Once the ridge 28 is inserted into the groove 16 in this starting area 46, the adjacent head portion of the ridge 28 causes the adjacent groove area to widen because of the partial insertion of the head 34 in the opening. Thus, the insertion of the ridge in this adjacent area is also facilitated, and so on around the periphery of the mid-sole. The head 34 of the ridge 28, and particularly the beveled edges 27 of the head, provides a leading edge or wedge which widens the opening 38 of the groove 16 to facilitate insertion. Therefore, the replacement shoe sole 26 of the present invention can be easily, manually applied to the mid-sole 12. The location of the starting area 46 can be indicated by a small arrow or other indication means on the side of the shoe, as shown at 48 in FIGURE 4.

FIGURES 9-12 illustrate the replaceable toe of the present invention as it operates on a ridge/groove interconnection. FIGURE 9 illustrates the replaceable toe 48 shown mounted on a shoe illustrated in phantom. The exploded view of FIGURE 10 illustrates the replaceable toe 48 when removed from the toe portion 50 of the shoe. The toe portion 50 of the shoe is manufactured in accordance with well-known principles, but is provided with a substantially horizontal groove 52. On the inner surface 54 of the replaceable toe 48 is found a corresponding ridge 56 having an undercut to provide both a head 58 and a neck 60. As shown in FIGURE 11, the replaceable toe 48 is attached to the toe portion 50 of the shoe by means of the ridge and groove interconnection. As with the ridge/groove interconnection described above, the undercut portion of the ridge 56 cooperates with the projections 62 forming the opening of the groove to maintain the toe 48 firmly in position. In addition, the replaceable toe 48 can be provided with a partial sole member 64 which overlaps the replaceable sole 26 as shown in FIGURE 11. This partial sole member 64 provides additional retentive force for the replaceable sole 26. Alternatively, as shown in FIGURE 12, the replaceable toe 48 can be constructed so as to be simply flush with the sole 26 of the shoe.

FIGURE 13 illustrates a base member 66 which can serve as a base for a snow shoe or cross-country ski (not shown) . The base member 66 is essentially planar and rectangular. It is preferably rigid, being constructed out of polyurethane or other rigid plastic material which is strong and durable, yet lightweight. The base member 66 can be provided with any type of attachment means 68 for the attachment of snow shoe devices or cross-country ski devices. On the top surface of the base member is found a sole 70 having a ridge configuration 72 similar to that described above.

Because snow shoeing and cross-country skiing requires leg and foot movement very similar to normal walking, in which the heel of the wearer rises and falls, this sole 70 shown in FIGURE 13 is attached only in the toe and ball of the foot area. The heel 74 is not attached to the base member 66 to permit the lifting of the heel during walking, as shown in phantom at 74a in FIGURE 3. The ridge 72 is broken in two adjacent portions as indicated at 76 in order to provide a hinge to facilitate the lift motion.

FIGURES 14 and 15 illustrate a shoe or boot 77 which is used with the base member 66 of FIGURE 13. As described above, the ridge 28 mounted on the replaceable shoe sole 26 may be removed from the groove 16 due to large removal forces. This occurs when lateral or twisting forces cause the protrusions which form the opening of the groove to be distorted, thus widening the opening and permitting the ridge to be removed. This is particularly true in cross-country skiing or snow shoeing in which vertical removal forces are very high and where the security of the interconnection between the ridge and groove is important. However, the interconnection must be capable of being broken in the event that the wearer falls. If the cross-country ski or snow shoe does not become removed from the boot or shoe of the wearer, serious injury could result. Thus, it is desirable that a secure interconnection be maintained without an unremovable locking situation so as to avoid injury to the wearer.

The shoe 77 illustrated in FIGURES 14 and 15, in connection with the base member 66 of FIGURE 13, accomplish these goals by providing a dual-clamping device 78 shown particularly in FIGURE 14. This dual-clamping device 78 reinforces the walls of the groove 80 to minimize distortion of the groove opening, thus maintaining a secure, but removable interconnection between the ridge 72 and of the base plate 66 and the groove 80 of the boot 77. Referring particularly to FIGURE 14, there is shown a shoe or boot 77 having a groove 80 as described above, and in addition, a central, hollowed area 82 which accommodates the clamping device 78. The hollowed area 82 is defined by an inner wall 84 which is adjacent the groove 80. The clamping device 78 is comprised of a pair of opposite wedges, including a front wedge 86 which presses forwardly against the inner wall 84 near the toe or ball area of the mid-sole, and a rear wedge 88 which presses rearwardly against the inner wall 84 near the heel of the mid-sole. It should be pointed out that the toe or ball as well as the heel section of the mid-sole of the shoe or boot experiences the greatest removal forces. These wedges 86 and 88 are mounted on a rigid rod 90 which is also flexible in its center portion 92. The flexible portion 92 of the rod 90 can be comprised of a bowdin wire, or some other suitable device which is flexible to transverse forces but transmits longitudinal forces in a rigid fashion.

The rear wedge 88 is threadedly mounted on a threaded portion 94 of the rod 90 while the front wedge 86 is rigidly mounted thereon. To the rear of the rear wedge is a thumb screw 96 for rotating the rod 90. The thumb screw 96 fits in a cut-out portion 98 in the mid-sole of the shoe as indicated in Figure 14. Preferably, the wedges 86 and 88 are of the same configuration or have the same slope on their sides so that they exert an equal amount of pressure both rearwardly and forwardly. Alternatively, one can adjust the clamping pressure at the toe or heel by varying the rate of change of the slope or shape of the wedges. FIGURE 15 is a side view of the clamping device 78 described above and the base member 66 shown in FIGURE 13, but does not illustrate the shoe 77 or its hollowed mid- sole. The cross-section in FIGURE 15 illustrates the threaded portion 94 of the rod 90 which threadedly mates with the rear wedge 88, and also illustrates the flexible center section 92. The forward wedge 86 is rigidly mounted on the rod 90 by means of a suitable fastener 97. Thus, as the thumb screw 96 is manually turned by the wearer, the rod 90 advances forward and elongates. The rear threaded portion 84 advances through the rear threaded wedge 88. Both wedges 86 and 88 are snugly, but not tightly mounted in the hollowed section 82 of the shoe 77 so that the sloping edges are adjacent the inner walls 84 of the hollowed area 82. As the thumb screw 96 turns and the clamping device 78 elongates, the sides of the forward wedge 86 engage the inner walls 84 and the forward force is reacted rearwardly, causing the rear wedge 88 to also engage the inner walls 84 of the hollowed area 82.

In operation, the user is wearing a pair of shoes or boots constructed in accordance with the shoe 77 shown in FIGURE 14. If the wearer desires to put on a pair of snow shoes or cross-country skis, he simply steps onto the base member 66 as shown in FIGURE 13 on which are mounted snow shoe or cross-country ski devices. Thus, there is no need to change shoes. The opening of the groove 80 in the embodiment shown in FIGURE 14 is slightly wider than previously described so as to facilitate insertion of the ridge 72 of the base member 66. A wider opening is possible because the wearer is not relying solely on the press fit between the ridge and the groove for retention, but also on the pressure applied by the clamping device 78. After stepping onto the base member 66 and causing the ridge 72 to be inserted within the groove 80, the user simply turns the thumb screw 96 causing the wedges 86 and 88 to separate from one another and to apply a wedging or lateral pressure to the inner walls 84 of the hollowed area 82. This pressure causes the ridge 72 to be clamped into the groove 80 and to be securely maintained therein. However, in the event of a fall, the flexibility of the materials of the mid-sole, including the clamping device 78, permits the shoe 77 to come off of the ridge

72, preventing injury to the wearer. In addition, the normal heel-lifting action utilized in using snow shoes or cross country skis can still be accomplished because of the flexible >rod 90 of the clamping device 78 and because of the flexible heel 74 mounted on the base member 66, as indicated in phantom at 74' and 78' in FIGURES 13 and 15.

Thus, the replaceable shoe sole of the present invention can be adapted for use in a wide variety of applications, which applications are not necessarily limited to those shown in the drawings or described herein. ^•

Claims

WHAT IS CLAIMED IS:

1. A shoe adapted to receive interchangeable, replaceable soles for participating in a variety of athletic, work, or casual activities, comprising: an upper shoe portion to receive the foot of the wearer of said shoe; a mid-sole formed on the bottom surface of said upper shoe portion and having a groove recessed into said bottom surface, said groove having a relatively narrow opening provided by opposing, longitudinal protrusions; and a sole having top and bottom surfaces, said bottom surface having traction means, cleats, or the like formed thereon, and said top surface having a ridge formed thereon for removable engagement with said groove, said ridge having substantially the same configuration as said groove and being relatively wide ' to provide, in cooperation with said opening of said groove, retention means for maintaining said sole in place on said mid-sole of said shoe to withstand lateral removal forces exerted on said sole during use of said shoe by the wearer of said shoe.

2. The shoe of Claim 1, wherein said ridge has substantially the same longitudinal and cross -sectional configuration as said groove on said mid-sole and is comprised of a head portion which is relatively wide compared to said opening to provide said retention means.

3. The shoe of Claim 1, further comprising means on the top surface of said sole interacting with said mid- sole to distribute said removal forces more broadly over said mid-sole to reduce the amount of said forces acting on said groove to maintain said sole in place on said mid- sole during a wide variety of activities.

4. The shoe of Claim 1 , wherein said interacting means on said sole comprises a projection, said projection ating with a corresponding cavity formed on said mid- sole.

5. The shoe of Claim 1, wherein said groove and said ridge are substantially continuous and located adjacent the periphery of said mid-sole of said shoe.

6. The shoe of Claim 4, wherein said projection comprises at least a single projection located near the ball portion of the top surface of said sole

7. The shoe of Claim 1, wherein said interacting means comprises plural projections formed on said sole and mating with corresponding cavities on said mid -sole.

8. The shoe of Claim 1 , wherein a relatively short portion of the length of said groove is provided with a wider opening in order to facilitate the insertion of said ridge therein.

9. A method for replacing or interchanging the sole of a shoe to permit repair of the worn sole or replacement with a sole having cleats or other tread devices, said shoe having a mid-sole on the bottom surface thereof, comprising : forming on said mid-sole a substantially continuous groove having a relatively narrow opening; forming on the top surface of said sole to be replaced or interchanged a substantially continuous ridge having a head which is wider than the opening of said groove; forming in at least one location on said groove an opening which is substantially as wide as the width of said ridge; manually forcing said ridge into said groove at said one location, said ridge, in a location adjacent to said one location, forcing the opening of said groove to widen; manually forcing the ridge into said groove at said adjacent location; repeating the last step until said ridge is completely pressed into said groove.

10. A shoe adapted to receive a replaceable toe in the event of wear or damage to the toe of the shoe, comprising : a toe portion on said shoe having a substantially continuous groove formed therein; and a replaceable toe for removable mounting on said toe of said shoe, said replaceable toe having a ridge formed thereon of cross-section substantially the same as the cross-section of said groove for mounting said replaceable toe on the toe of said shoe.

11. The shoe of Claim 10, wherein said ridge is pressed fit into said groove, said groove being provided with means for retaining said ridge therein.

12. The shoe of Claim 10, wherein said replaceable toe is provided with a flange for overlapping the sole of said shoe.

13. A device for use in snow shoeing, cross-country skiing, and the like, comprising: a shoe for receiving the foot of a wearer, said shoe having a bottom surface and a substantially continuous groove formed in said bottom surface; a substantially rigid base member; means for removably attaching to said base member snow shoe means, cross-country ski means,* and the like; and a flexible binding mounted on said base member comprising a substantially continuous ridge adapted to be removably interconnected with said groove, the rear portion of said ridge being flexible to permit the heel of the wearer to rise and fall as in normal walking motion.

14. The device of Claim 13, further comprising means for exerting pressure on said groove to more securely retain said ridge therein.