US3870325A

US3870325A - Combined ski boot and binding

Info

Publication number: US3870325A
Application number: US327432A
Authority: US
Inventors: Edgar H Davis
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-01-29
Filing date: 1973-01-29
Publication date: 1975-03-11
Anticipated expiration: 1992-03-11
Also published as: DE2402974A1; IT1008158B; JPS49110429A; CA994826A

Abstract

A combined ski boot and binding giving improved protection from leg breakages includes a two part boot having an ankle cuff portion pivotal about a base portion, and a releasable rear binding which directly connects the ankle cuff portion and the ski. The rear binding releases not only in response to a forwards pivotal force applied to the whole boot, as in conventional safety release bindings, but also, at least partly, in response to pivotal movement between the ankle cuff portion and the base portion of the boot. Another feature of the invention is a toe binding comprising a support pivotal about an axis normal to the ski, the support carrying two laterally spaced spring biased plungers, the ends of which engage in recesses in the toe of the boot, so that release of the toe can occur by simultaneously sideways swiveling of the boot and the support.

Description

United States Patent 1191 Davis 1451 Mar. 11, 1975 22 Filed:

1 1 COMBINED SKI BOOT AND BINDING Jan. 29, 1973 [21] Appl. N0.: 327,432

[52] US. Cl. 280/1l.35 N, 36/2.5 AL, 280/11.35 R [51] Int. Cl. A63c 9/086 [58] Field of Search280/1 1.35 R, 11.35 T, 11.35 N,

280/11.35 K, 11.35 C, 11.35 Y; 36/25 AL [56] References Cited UNITED STATES PATENTS 2,669,459 2/1954 Fleming 280/11 35 R 3,160,421 12/1964 Bugg 280/11 35 K 3,511,516 5/1970 Smolka ct a]. 280/1 1.35 C 3,753.571 8/1973 Gcrtsch ct a1 280/1 1.35 K 3.781.028 12/1973 Gcrtsch ct al 280/1 1.35 K

FOREIGN PATENTS OR APPLICATIONS 1,912,950 9/1970 Germany 280/1 1.35 N

Primary Etaminer-David Schonberg Assistant Examiner-David M. Mitchell Attorney, Agent, or Firm-Cushman, Darby and Cushman 57 ABSTRACT A combined ski boot and binding giving improved protection from leg breakages includes a two part boot having an ankle cuff portion pivotal about a base portion, and a releasable rear binding which directly connects the ankle cuff portion and the ski. The rear binding releases not only in response to a forwards pivotal force applied to the whole boot, as in conventional safety release bindings, but also, at least partly, in response to pivotal movement between the ankle cuff portion and the base portion of the boot. Another feature of the invention is a toe binding comprising a support pivotal about an axis normal to the ski, the support carrying two laterally spaced spring biased plungers, the ends of which engage in recesses in the toe of the boot, so that release of the toe can occur by simultaneously sideways swiveling of the boot and the support.

12 Claims, 8 Drawing Figures VPATENTEDHARI 1 1915- 3. 70325 sum 1 or 4 PATENTEU H975 Q I 3,870,325

FIGS

COMBINED SKI BOOT AND BINDING I The present invention relates to a ski boot andbinding arrangement designed to give greater protection against injury in certain types of falls than that given by known safety release bindings.

One feature of the invention is the rear binding means, which protect the skier from leg injuries in a forward fall particularly when downwards pressure is applied to the ski.

Conventional modern safety release rear bindings for ski boots include a clamping device which grips a rearwards lug or other projection on the heal of the boot, the clamping device being arranged to release in the event of excessive upwards force being applied by the heel of the boot on the binding. Such excessive forces may occur either by the skier falling forwards while the skis remain on the snow, so that the boot (which is very stiff) is caused to pivot forwardly about the toe, or by a direct pull of the boot from the ski, or by combinations of these movements. Heel bindings of this kind must of course be combined with toe bindings which permit the various movements of the boot giving the heel release. A typical modern safety release heel binding is shown in U.S. Pat. No. 3,556,543 which issued on Jan. 19, 1971 to Dovre Ski Binding Inc.

These conventional bindings have their drawback in that they allow leg fractures to occur in certain situations, particularly where a skier falls forward at the same time as he is applying strong downwards pressure to the skis, for example on bottoming after passing over a bump, or on the landing after a jump. In such cases, the downwards pressure on the boot as a whole counteracts the upperwards force on the heel binding caused by the forwards fall, so that the heel does not necessarily release. The leg may thus be subject to excessive forces, causing fracture, without release of the heel. When the skier is wearing high rigid boots, as nowadays preferred by good skiers, accidents of this kind are likely to cause fracture of the fibula in the leg, which is regarded as a serious injury.

The present invention has as one object to provide a combined ski boot and binding which will reduce injuries particularly of the serious type described above.

The present invention is not merely concerned with a new type of binding, but the combination of this with a boot which forms an integral part of the invention. The boot includes a base portion and an ankle cuff portion pivotal on the base portion about a transverse axis, which axis is preferably coincident with the skiers ankle joint. The binding includes a front or toe binding for releasably holding the toe of the base portion of the boot, and a rear binding for holding the heel of the boot against the ski, the rear binding including means for releasing the heel in response both to pivotal movement of the boot as a whole about the toe through a predetermined abnormal angle, and to pivoting of the base portion of the boot about the toe through an angle smaller than this predetermined angle when combined with forwarding pivoting of the ankle cuff portion relative to the base portion about the pivotal axis.

This arrangement is believed to be unique in taking account of the pivoting of an ankle cuff portion about a pivotal axis roughly coincident with a skiers ankle joint, to cause release of the boot when this amount of pivoting, taken in combination with pivoting about the toe, corresponds to an excessive bending moment on the leg. Furthermore, the rear binding includes resilient means acting between the ankle cuff portion and the ski, said resilient means being arranged to allow limited forward pivoting of the ankle cuff portion while increasing the release forces on the rear binding but allowing the base portion to remain in firm contact with the ski. This ensures that the release angles referred to above correspond to predetermined bending moments on the leg.

Preferably, the rear binding includes releasable connecting means directly connecting the ski and a part of the ankle cuff portion behind the pivotal axis thereof. the releasable connecting means being sufficiently extendible to allow some forward pivotal movement of the cuff portion about this transverse axis during skiing. and sufficiently resistant to extension to hold the ski in normal skiing position on the boot during skiing, the releasable connecting means being capable of release when excessive force is applied thereto.

The rear binding may also yieldably restrain pivota movement of the ankle cuff portion, so that the skier can lean forwards or backwards against a spring force which urges the ankle cuff portion into a neutral position. For this purpose, the said part of the ankle cuff portion behind the pivotal axis thereof includes means projectng rearwardly from the ankle cuff portion and defining a slideway extending generally to the longitudinal axis of the cuff portion, and the releasable connecting means includes the combination of:

l. releasable retaining means adapted to be permanently attached to the ski, and

2. deformable connecting means comprising in combination a rod having means at its lower end capable of being retained in said retaining means and having a shaft portion slidable in said slideway and spring means restraining downwards movement of said rod relative to said cuff portion. The rod is flexible to allow limited resiliently restrained pivoting of the cuff portion about its transverse pivotal axis, the spring means being sufficiently stiff normally to retain the heel of the boot on the ski in normal skiing position. The rod may be bent both forwards and backwards from the neutral position which represents the normal optimum skiing angle for the ankle cuff portion.

Boots formed of two parts, namely a base portion and an ankle cuff portion pivotal on the base portion, are known, for example from Canadian Pat. No. 889,586 issued Jan. 4, 1972 to Caporicci. However, the bindings used with boots of this type have previously been of conventional type which merely connects the base portion of the boot to the ski, and which do not give any release effect caused by pivoting of the ankle cuff portion relative to the base portion.

It is also well known to have safety straps which directly connect the ski to the ankle portion of a boot (for example, see U.S. Pat. No. 2,491,485 to Durham issued Dec. 20, 1949). However, these straps have been used only as an auxiliary to the main binding, merely intended to prevent loss of the ski after the main binding has released. A safety strap of this kind is fairly loose and/or readily extensible, and would not be subject to any kind of excessive tension until the boot has been released by the main binding.

Another feature of this invention is an improved front or toe binding, particularly suitable for use with the heel binding described, but also usable with conventional heel bindings.

The improved toe binding is a modification of a type of binding known as the Gertsch binding. In the Gertsch binding, a support is solidly fixed to the ski in front of the toe portion of a boot, this support carrying a single spring loaded plunger having a projecting rounded end which engages a recess in a toe plate attached to the toe of the boot. The toe binding is used with a heel binding which locates the heel firmly and prevents rearwards movement of the boot, and the projecting end of the spring loaded plunger engages the recess to maintain the toe in place in normal skiing. The recess in the toe plate is shaped so that if the boot is subjected to excessive swiveling force about the axis of the skiers leg, or to an excessive upwards pull on the toe, the plunger will be forced back against its spring and the toe will release. This type of toe binding has the drawback that it is likely to release not only when a skier falls, but also when the binding is subjected to shock loads for example, caused by the ski passing over ruts or running at high speeds. Release of the ski caused by such shock loads is undesirable as it may cause the skier to fall and injure himself.

In the modification of the Gertsch binding provided for by this invention, the support has two parallel bores carrying two spring loaded plungers which engage in two laterally spaced recesses in the toe of the boot. Also, the support, instead of being fixed, is made pivotal about a vertical axis (i.e., an axis normal to the top surface of the ski), this vertical axis being situated between the two plungers. The plungers are axially displacable by an amount sufficient to allow the boot to release by simultaneous sideways swiveling movement of the boot and of the support beyond a position in which the projecting end of a plunger lies directly between the vertical axis of the pivot and the locating means for the heel. The binding also preferably releases by upwards pull on the toe.

This new toe binding permits some sideways movement of the toe without release of the binding, so that release is not likely to occur under the influence of shock loads such as would not cause the skier to fall. Also, the use of two laterally spaced plungers allows the ski to be held firmly onto the boot so that when the ski is edged the ski and boot rotate as one.

In order that the invention may be properly understood, a preferred embodiment thereof is shown in the accompanying drawings, in which:

FIG. 1 is a side view of a combined ski binding and boot;

FIG. 2 is an enlarged side view of part of the rear binding;

FIG. 3 is a plan view of part of the rear binding on section line 33 of FIG. 2, and shown with locking means removed,

FIGS. 3a and 3b are respectively a top plan view and a rear view of locking means for the rear binding;

FIG. 4 is a detailed side view of the ankle cuff portion of the boot, showing another part of the rear binding;

FIG. 5 is a detailed side view of the toe binding, and

FIG. 6 is a detailed plan view of the toe binding.

Referring to FIG. 1, a portion ofa ski 10 is shown on which is mounted a toe binding 12 and part of a heel binding 14. The area of ski intermediate the toe and heel binding preferably has one or more raised plates such as plate 18 of FIG. 5 for receiving the sole of the boot.

The boot 16 comprises a base portion 20 which extends tojust above the ankle joint of a skier, and which is formed by moulding plastic material under or over a metal reinforcing insert 21, which extends up the ankle at both sides of the boot. The base portion has the conventional opening with buckles 23. The upper ends of insert 21 provide bearings for pivots 24 carrying an ankle cuff portion 26, which is of relatively rigid plas tics material and which has a front opening closed by buckle 27. The transverse pivotal axis formed by bindings 24 is approximately coincident with the ankle joint of a skier, so that the boot permits relatively free for wards pivoting of the ankle but braces the ankle firmly against sideways twisting when the skier is attempting to edge the skis. The ankle cuff portion 26 has a rear upwards extension 26a which reaches a height about the pivots 24 greater than the height of these pivots above the sole of the boot.

The ankle cuff portion 26, shown in more detail in FIG. 4, has spaced upper and

lower extensions

30 and 31 projecting rearwardly thereof. The upper extension 30 is near the upper end of extension 260. and the lower extension 31 is in the same axial position along the cuff portion as are the pivots 24. Upper extension 30 is integral with the plastics material of the cuff portion, and lower extension 31 is part of a metal yoke member 33 having arms which extend partly around the inside surface of the ankle cuff portion, the ends of the arms having bearings engaging with the pivots 24. The yoke member 33 is very rigidly attached to the ankle cuff portion. v

The upper and

lower extensions

30 and 31 each define a bore extending generally parallel to the longitudinal axis of the cuff portion, these bores being aligned with each other. These bores together form a slideway for the shaft portion 35 of a slightly flexible steel rod 36. The top end of the rod is a close fit in extension 30, and an air hole may be provided communicating with the top end of the bore in this extension to allow for movement of air into and out of the bore as the rod moves upwards and downwards in the lower part of the bore. The part of shaft portion 35 slidable in extension 31 is non-circular in section, as is the bore in extension 31, so that the rod 36 is prevented from rotating out of the position shown.

The downwards movement of the rod 36 relative to the ankle cuff portion is restricted by a stiff compression spring 38 retained between the upper side of extension 31 and a stop member 39 adjustably mounted on the shaft portion 35. The ends of the coil spring 38 engage in the extension 31 and in the stop member 39, so that both tension and compression can be applied to the spring. The combination of rod 36, spring 38 and stop member 39 form extendible connecting means between the fixed point on the ankle cuff portion constituted by extension 31, and releasable retaining means indicated at 14b which will be described below.

The portion 41 of rod 36 below extension 31 is thicker than the shaft portion 35 and is bent outwardly from the heel of the boot, and terminates in a flattened end portion 43 (shown in detail in FIGS. 2 and 3) which is bent inwardly so as to be approximately normal to the ski. At the top of the portion 43 the rod is provided with a ball member 45, which actually takes the form of a hemi-spherical projection on one side of the flattened portion 43, as shown in FIG. 3. The ball member 45 and the flat portion 43 cooperate with the releasable retaining means 14b to be described.

The releasable retaining means 14b is shown in detail in FIGS. 2, 3, 3a, and 3b. These retaining means include a base plate 50 adapted to be permanently attached to the ski 10, and a rigid upstanding plate 51 cast integrally with the base plate and having an upwardly projecting portion 51a. The forward end of plate 51 is thickened as at 52, and the front face of this is provided with a ridge 53 having a nearly vertical portion 52a extending upwardly from the ski, and which provides locating means for a cleft 21a in the heel of the boot and which precisely positions the boot in fore and aft position. Above the portion 52a is a rearwardly curved portion 53b against which the heel can slide when the boot is being placed in the binding. To the rear of plate 51 is hinged at 54 a spring clip 55 also having an upwardly projecting portion 55a disposed in opposition to projecting portion 51a when the clip is in the closed position shown, i.e., parallel to plate 51. The clip 55 can be held in this closed position by a locking member 58 mounted on a horizontal pivot carried by an upstanding lug 59 connected to plate 51 near the hinge 54. The locking member 58, which is omitted from FIG. 3 for clarity, is shown separately in FIGS. 3a and 3b. This locking member includes two

opposed side plates

58a and 58b defining a recess which receives the outer surfaces of plate 51 and clip 55 to hold the clip in closed position parallel to the plate 51. Plate 58a is vertical and slides over plate 51, while plate 58b flares outwardly as shown in FIG. 3b. The plate 58b has an inner swelling 58c which snaps over an outwardly turned lip 56 on the top of clip 55 when the locking member is in the locking position shown in FIG. 2, maintaining the locking member in this position. The member 58 also has horizontal flanges 60 providing for easy manipulation, these flanges having holes 60a sized to receive the tip of a ski pole.

The projecting portion 55a of the clip has an enlarged head 62 carrying an insert 63 having a recess facing inwardly and shaped to receive the projecting part of the ball member 45. The insert 63 is of Tef- Ion, this being a registered trade mark for polytetrafluoroethylene. The arrangement is such that with locking member 58 in the raised position, the clip 55 can be hinged away from plate 51 so that the lower portion 43 of rod 36 can be inserted or removed from between the projections 51a and 55a, and with the locking member 58 in the closed position of FIG. 2 this holds the clip 55 in place and retains the ball member in the socket member formed by the combination of plate 51 and clip 55. The clip 55 is slightly flexible, and in addition the insert 63 is slightly resilient, so that the ball member can be pulled from the socket member, without movement of the locking member 58, when extreme tension or other forces are applied to rod 36, under conditions described below.

It may be noted that the inside faces of

parts

51 and 55 provide opposed surfaces facing opposite sides of the ski, which engage with the sides of rod portion 43 to limit sideways angular movement of the rod relative to the ski.

Also integral with plate 51 is an upstanding projection or horn 66 having a sloped, rearward facing surface 66a situated below and slightly forward of the socket member described. In the normal skiing position of rod 36 this surface 66a is spaced just in front of the front bottom corner of end portion 43 of rod 36, by an amount such that if the skier leans backward by.,an undue amount, e.g., such 'as to release the toe of the boot from the toe binding, pivoting of rod 36 about the socket member causes portion 43 to contact surface 660. Further backward pivoting from this position causes the ball member to be forced out of the socket member, releasing the heel binding.

FIGS. 5 and 6 show in detail the toe binding. 12. This comprises a mounting lOO adapted to be permanently attached to the ski 10 by screws and providing a mount for a vertical pivot pin 102 which carries a support 101 and which allows rotation of the support about a vertical axis (i.e., an axis normal to the ski). The support has two cylindrical portions defining two paralle bores spaced apart on opposite sides of the pivot pin 102, both of the cylindrical portions 104 being at the same height above the top of the ski. In the operative position shown, the cylindrical portions 104 are both parallel to and spaced symmetrically on opposite sides of the center line of the ski, which center line also passes through the center ofthe locating means for the heel of the boot constituted by the ridge 53. The support 101 is releasably retained in this aligned position by spring means which are not shown.

Each of the bores of the cylindrical portions 104 carries a spring loaded plunger having a rounded projecting end 106. The forward end of each of the springs biasing the plungers (i.e., the ends of the springs remote from the boot) is retained in place by a screw provided with an adjustment knob 108. Between knob 108 and the forward end of the portion 104 are positioned spacers 110, the number of which can be varied to alter the compression of the springs acting on the plungers. The projecting ends 106 of the plungers engage in two laterally spaced forwards facing recesses or depressions 112 in the front, toe end of the sole of the boot. The recesses are shaped in side and plan view as indicated in FIGS. 5 and 6, and generally have a concave curvature of radius slightly larger than the rounded ends of the plungers. The lower lands of the recesses are slightly cut away, and slope downwardly from the bottom of the recess at an angle of roughly 45.

The plungers are axially displaceable against their springs by an amount sufficient to release the toe binding in two different ways. Firstly, if the boot is subjected to a rearwards pivoting about the heel, or very strong upwards forces away from the ski, then the plungers will be depressed sufficiently against their springs to clear the lower lands of the recesses and allow release of the toe of the boot. Secondly, the plungers can be displaced sufficiently to allow the boot to release by simultaneous sideways swiveling of the boot (about the axis of the skiers leg) and swiveling of the support 101 about pivot 102 beyond a position in which the projecting end of a plunger lies directly between the pin 102 and the center of the heel locating means constituted by ridge 53, i.e., beyond the position where the end of the plunger is on the center line of the ski. This constitutes a dead center" position, and the boot toe can move sideways up to this position and still be returned to the normal skiing position by the restoring forces of the spring acting on the plungers. For this reason, this toe binding is not readily caused to release under shock loads, as happens with the known Gertsch binding. As mentioned, spring means within the support 101 are also provided to restrain swiveling of the support 101 from the aligned position, and these are helpful in keeping the support positioned when the boot is being inserted.

The springs acting on the two plungers may be separately adjusted so that the toe releases more readily by twisting in one direction than in the other.

It may be noted that this toe binding does not impose any restraint on forwards pivoting of the boot about the toe, when the heel binding releases or is about to release.

In operation, the boot 16 is inserted into the bindings by firstly closing the locking member 58 into the looking position shown in FIG. 2, and then inserting the toe into the toe binding with the plunger ends 106 engaging in recesses 112. The flat end portion 43 of the rod 36 is placed in position between the projections 51a and 55a of the retaining means, and the heel of the boot is then lowered until the cleft 21a engages the rearwards sloping portion 53b of the ridge 53 and causes the toe of the boot to move forwards and compress the plunger springs so that the rounded ends of the plungers are held in the recesses 112. Final downwards pressing of the heel causes ball member 45 to snap into the insert 63, with slight flexing of clip 55.

In this condition, the bindings hold the boot firmly on the ski, while allowing for very limited movement between the ski and the boot to accommodate shock loadings on the ski. Thus, the boot can swivel slightly with the toe portion sliding sideways on plate 18, and with resultant swiveling of support 101, providing that the ends of the plungers do not pss beyond the center line ofthe ski. Also, the spring 38 allows very slight lifting of the heel from the ski before release of the heel takes place. The ankle cuff portion can pivot slightly about the pivots 24, this movement being allowed for by the flexibility of the rod 36. The need to bend the rod 36, and to compress or extend the spring 38, imposes resistance on both forward and rearward pivoting of the ankle cuff portion, so that the ankle cuff portion is continually, resiliently urged into a neutral position which is chosen so as to be most desirable for normal skiing. The spring 38 is sufficiently strong to maintain the heel in normal skiing position on the ski (i.e., with the heel not lifting by more than a very small amount) in the absence of any other holding means such as conventional heel clamps. In addition, when the skier wants to edge the skis, the bindings ensure that the ski rotates with the boot, by virtue of the manner in which the plungers act in the recesses in the toe of the boot, and also by virtue of engagement of the flattened portion 43 of the rod 36 against the inside surfaces of plate 51 and clip 55. When it desired to remove the skis, the locking member 58 is pivoted upwards to an open position, releasing clip 55 and allowing the skier to step out of the binding. Movement of the locking member to the open position can be effected by means ofa ski pole the tip of which can be inserted in one of the holes 60a.

If the skier falls forward in such a manner as to cause pivoting of the boot as a whole about the toe through an angle greater than a small predetermined angle dependent on the compression in spring 38, the rear binding will release by the ball member 45 pulling out of the socket formed by the plate 51 and clip 55. This occurs when the rod 36 is subject to extreme forces, which may be a combination of tensile forces and bending forces urging release of the ball member sideways. The predetermined angle by which the boot as a whole can pivot about its toe before release will be predetermined by reference to known data on safety release heel bindings, but such angle must be small enough that in normal skiiing there is no undue lifting of the heel. Release in this way is similar to that of conventional safety release bindings. In addition, however, the rear binding can release in conditions when the downwards force on the leg opposes the pivotal movement of the boot as a whole to such an extent that an exteme, injury causing bending moment on the shin bone cannot rotate the boot as a whole through the above-mentioned predetermined angle. In these circumstances, the bending moment on the shin bone causes pivoting of the ankle cuff portion about pivots 24 relative to the base portion, and thus causes upwards movement of extension 31 relative to the base portion, increasing the forces in the rod 36 so that the ball member 45 is released before the shin bone is subject to injury. This pivoting of the ankle cuff portion'will normally be combined with a tendency to pivot the boot as a whole about the toe, so that release in fact occurs by pivoting of the base portion of the boot about the toe through an angle smaller than the above-mentioned predetermined angle, combined with forward pivoting of the ankle cuff portion relative to the base portion about its pivotal axis. As

mentioned, the toe release imposes no restraint on this manner of heel release, and also allows release on swiveling of the boot about the leg axis, or by an upwards pull on the toe. Release can also occur by rearward pivotal movement, the heel binding releasing after contact occurs between the lower end of rod portion 43 and the surface 660, as described.

Reference is made in the foregoing and in the claims to the amount of pivoting of the boot portions which takes place before release, since this seems to be the most convenient way of understanding the forces involved. In all heel bindings known to me, it is possible for the heel to lift by a small but definite amount, say between A and *2; of an inch, before the heel is released. However, it will be appreciated that it is the various forces involved, rather than these angles, which are of primary importance, and the resilient means provided by the combination of the flexible rod 36 and the coil spring 38 ensure that there is a definite relationship between the angles of pivoting and the bending moment applied. Thus, the heel binding is such as to release when subjected to predetermined forces tending either to cause pivoting of the boot as a whole about the toe, or to somewhat lesser forces causing similar pivoting combined with forces causing pivoting of the ankle cuff position on the base portion.

It is anticipated that, unlike with boots and bindings presently used which are made by different manufacturers and fitted together and ajusted by shops selling these skis and bindings, the combination of the heel and toe bindings and of the boot will be sold as a single unit. This will mean that the release characteristics of the toe and heel bindings can be adjusted according to the size of the boot, and then fixed in position at the factory. The release characteristics of the heel binding depend on the stiffness of spring clip 55, which can be replaced should it be desired to adapt the binding to another skier. The two bindings and the boot may be held together, prior to fitting onto a ski, by a thin flexible plastic plate which will act as a template for the correct positioning and fixing of the bindings on the ski.

The binding of this invention is preferably used with a conventional safety strap such as that indicated at 80 in FIG. 1, and which prevents loss of the ski after release.

Various alternatives are possible within the scope of the invention. In particular, variations may be made to the shape of the ball member 45 and of the insert 63 to give desired release characteristics, and these maybe made dependent on the direction of forces on the ball member, for example by using a non-circular ball member. Specially shaped ball and socket members may also be designed so that inserting of the ball member into the socket member, on stepping into the binding, involves much less force than that required to release the ball member from the socket member by upward pull on the rod. Also, instead ofa hemispherical projection on one side only of rod end portion 43, the ball member may include similar projections on both sides of portion 43.

Another possible variation of heel binding within the general scope of this invention would be a heel binding of generally conventional type, having a clamping device which grips the base portion of the boot, coupled with a connector between the heel binding and the ankle cuff portion of the boot, the connector interacting with the heel binding in such manner as to assist release of the heel binding in response to forward pivoting of the ankle cuff portion about the transverse pivotal axis. Release of the heel binding in response to pivoting of the boot as a whole would of course still occur in the normal manner.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

l. A combined ski boot and binding, comprising:

a boot having a base portion and an ankle cuff portion pivotal on the base portion about a transverse pivotal axis,

a front binding for releasably holding the toe of said base portion, and

a rear binding for holding the heel of the boot against the ski, said rear binding including means for releasing the heel in response both to pivotal movement of the boot in a vertical plane as a whole about the toe through a predetermined abnormal angle, and to pivoting of the base portion of the boot about the toe in said vertical plane portion through an angle smaller than said predetermined angle combined with a forward pivoting of the ankle cuff portion relative to the base portion about said pivotal axis and wherein said rear binding includes resilient means acting on said ankle cuff portion, said resilient means being arranged to allow limited forward pivoting of the ankle cuff portion while increasing the release forces on the rear binding but allowing the base portion to remain in firm contact with the ski.

2. The combination of claim 1, wherein said rear binding includes locating means for the heel which limit rearwards movement of boot, and wherein the front binding comprises a support adapted to be permanently attached to the ski by means permitting pivotal movement about a vertical axis, said support having two parallel bores spaced apart on opposite sides of said vertical axis, each of said bores carrying a spring loaded plunger having a projecting end, the boot toe being provided with two laterally spaced, forwards facing depressions for receiving the projecting ends of the plungers, the spring loading of said plungers normally holding said projecting ends thereof in the depressions to hold the toe of the boot in place in normal skiing, the plungers being axially displaceable by an amount sufficient to allow the boot to release by simultaneous sideways swivelling movement of the boot and of the support beyond a position in which a projecting end of a plunger lies directly between said vertical axis and the locating means for the heel.

3. The combination of claim 2, also including a slide plate mounted on the ski in the region of the toe of the boot, and providing a surface on which the toe of the boot is slidable sideways.

4. A combined ski boot and binding, comprising:

a front binding for releasably holding the toe of said base portion, and

a rear binding for holding the heel of the boot against the ski, said rear binding including releasable connecting means directly connecting the ski and a part of the ankle cuff portion behind said pivotal axis, said releasable connecting means being sufficiently deformable to allow some forward pivotal movement of the cuff portion about said transverse axis during skiing, and sufficiently resistant to deformationto hold the ski in normal skiiing position on the boot during skiing, said releasable connecting means being capable of release when excessive forces are applied thereto either by pivoting of the boot as a whole in a vertical plane about the toe through a predetermined abnormal angle, or by pivoting ofthe base portion of the boot about the toe in said vertical plane through an angle smaller than said predetermined angle combined with forward pivoting of the ankle cuff portion relative to the base portion about said pivotal axis.

5. The combination of claim 4, wherein said transverse pivotalaxis is in the region of a skiers ankle joint, and wherein said part of the ankle cuff portion is a rigid extension projecting from the rear thereof.

6. The combination of claim 4, wherein said releasable connecting means comprises releasable retaining means adapted to be permanently attached to a ski, and deformable connecting means attached to said part of the ankle cuff portion behind said pivotal axis and cooperating with said retaining means in such manner that an extreme forces on said releasable connecting means releases the deformable connecting means from the retaining means, the resistance to deformation of said retaining means being such that said extreme forces in the deformable connecting means may be caused either by pivoting of the boot as a whole about the toe through a predetermined abnormal angle, or by pivoting of the base portion of the boot about the toe through an angle smaller than said predetermined angle combined with forward pivoting of the ankle cuff portion relative to the base portion about said pivotal axis.

7. The combination of claim 6, wherein said transverse pivotal axis is in the region of a skiers ankle joint, and wherein said part of the ankle cuff portion is a rigid extension projecting from the rear thereof.

8. A combined ski boot and binding, comprising:

a boot having a base portion and an ankle cuff portion pivoted to the base portion about a transverse pivotal axis,

a front binding for releasably holding the toe of said base portion onto a ski and allowing pivoting of said base portion in a vertical plane forwardly about said toe, and

a rear binding for holding the heel of said boot against the ski, said rear binding comprising:

a. releasable retaining means adapted to be permanently attached to a ski,

b. means projecting rearwardly from the ankle cuff portion and defining a slideway extending generally parallel to the longitudinal axis of the cuff portion, and

c. deformable connecting means comprising in combination a rod having means at its lower end capable of being retained in said retaining means and having a shaft portion slidable in said slideway and spring means restraining downwards movement of said rod relative to said cuff portion, said rod being flexible to allow limited resiliently restrained pivoting of the cuff portion about said transverse axis both forwardly and rearwardly of a neutral position, and said spring being sufficiently stiff normally to retain the heel of said base portion in normal skiing position on the ski, and wherein one or more of the interengaging parts of the rod and the releasable retaining means are resilient whereby extreme forces in the rod causes release of the rod from the retaining means, the resiliency of these interengaging part or parts, and the compressibility of the spring means and the unstressed length of the spring means being selected so that said extreme forces in the rod may be caused either by pivoting of the boot as a whole in a vertical plane about the toe through a predetermined abnormal angle, or by pivoting of the base portion of the boot in said vertical plane about the toe through an angle smaller than said predetermined angle combined with forward pivoting of the ankle cuff portion relative to the base portion about said pivotal axis.

9. The combination of claim 8, wherein said releasable retaining means is in the form ofa socket member, and wherein said means at the lower end of the rod is a ball member engageable with said socket member.

10. The combination of claim 9, wherein the said retaining means includes two opposed surfaces spaced from the socket member and facing opposite sides of the ski, and wherein said rod has an extension which engages between said surfaces and limits sideways angular movement of the rod relative to the ski.

ll. The combination of claim 8, wherein the means projecting rearwardly from the ankle cuff portion are spaced upper and lower extensions thereof each having a bore therein, said bores being aligned so as to define together said slideway, and wherein said spring means is retained between the upper side of said lower extension and a stop member on said shaft portion.

12. A ski boot adapted to be used in combination with a ski having a front binding and having part of a rear binding constituted by releasable retaining means in the form of a socket member, said boot comprising:

a. a base portion,

b. an ankle-cuff portion pivotal on the base portion about a transverse pivotal axis,

0. spaced upper and lower extensions projecting rearwardly from the ankle cuff portion and each defining a bore extending generally parallel to the longitudinal axis of the cuff portion, said bores being aligned with each other, and said lower extension being rigidly attached to the ankle cuff portion, and

d. extendible connecting means comprising in com bination a rod having a ball member at its lower end capable of being retained by said socket member and-having a shaft portion slidable in said bores, and spring means retained between the upper side of said lower extension and a stop member on said shaft portion, said rod being flexible to allow resiliently restrained pivoting of the cuff portion about said transverse axis, and said spring being sufficiently stiff normally to retain the heel of the said base portion in normal skiing position on the ski when said ball member is in position in said socket member, the compressibility of the spring means and the unstressed length of spring being selected in relation to the release characteristics of said ball and socket members so that extreme forces in the rod causes release of the ball member from the socket member, and so that said extreme forces may be caused either by pivoting of the boot as a whole in a vertical plane about the toe through a predetermined angle, or by pivoting of the base portion of the boot in said vertical plane about the toe through an angle smaller than said predetermined angle combined with forward pivoting of the ankle cuff portion relative to the base portion about said pivotal axis.

Claims

1. A combined ski boot and binding, comprising: a boot having a base portion and an ankle cuff portion pivotal on the base portion about a transverse pivotal axis, a front binding for releasably holding the toe of said base portion, and a rear binding for holding the heel of the boot against the ski, said rear binding including means for releasing the heel in response both to pivotal movement of tHe boot in a vertical plane as a whole about the toe through a predetermined abnormal angle, and to pivoting of the base portion of the boot about the toe in said vertical plane an angle smaller than said predetermined angle combined with a forward pivoting of the ankle cuff portion relative to the base portion about said pivotal axis and wherein said rear binding includes resilient means acting on said ankle cuff portion, said resilient means being arranged to allow limited forward pivoting of the ankle cuff portion while increasing the release forces on the rear binding but allowing the base portion to remain in firm contact with the ski.

4. A combined ski boot and binding, comprising: a boot having a base portion and an ankle cuff portion pivotal on the base portion about a transverse pivotal axis, a front binding for releasably holding the toe of said base portion, and a rear binding for holding the heel of the boot against the ski, said rear binding including releasable connecting means directly connecting the ski and a part of the ankle cuff portion behind said pivotal axis, said releasable connecting means being sufficiently deformable to allow some forward pivotal movement of the cuff portion about said transverse axis during skiing, and sufficiently resistant to deformation to hold the ski in normal skiiing position on the boot during skiing, said releasable connecting means being capable of release when excessive forces are applied thereto either by pivoting of the boot as a whole in a vertical plane about the toe through a predetermined abnormal angle, or by pivoting of the base portion of the boot about the toe in said vertical plane through an angle smaller than said predetermined angle combined with forward pivoting of the ankle cuff portion relative to the base portion about said pivotal axis.

5. The combination of claim 4, wherein said transverse pivotal axis is in the region of a skier''s ankle joint, and wherein said part of the ankle cuff portion is a rigid extension projecting from the rear thereof.

7. The combination of claim 6, wherein said transverse pivotal axis is in the region of a skier''s ankle joint, and wherein said part of the ankle cuff portion is a rigid extension projecting from the rear thereof.

8. A combined ski boot and binding, comprising: a boot having a base portion and an ankle cuff portion pivoted to the base portion about a transverse pivotal axis, a front binding for releasably holding the toe of said base portion onto a ski and allowing pivoting of said base portion in a vertical plane forwardly about said toe, and a rear binding for holding the heel of said boot against the ski, said rear binding comprising: a. releasable retaining means adapted to be permanently attached to a ski, b. means projecting rearwardly from the ankle cuff portion and defining a slideway extending generally parallel to the longitudinal axis of the cuff portion, and c. deformable connecting means comprising in combination a rod having means at its lower end capable of being retained in said retaining means and having a shaft portion slidable in said slideway and spring means restraining downwards movement of said rod relative to said cuff portion, said rod being flexible to allow limited resiliently restrained pivoting of the cuff portion about said transverse axis both forwardly and rearwardly of a neutral position, and said spring being sufficiently stiff normally to retain the heel of said base portion in normal skiing position on the ski, and wherein one or more of the inter-engaging parts of the rod and the releasable retaining means are resilient whereby extreme forces in the rod causes release of the rod from the retaining means, the resiliency of these inter-engaging part or parts, and the compressibility of the spring means and the unstressed length of the spring means being selected so that said extreme forces in the rod may be caused either by pivoting of the boot as a whole in a vertical plane about the toe through a predetermined abnormal angle, or by pivoting of the base portion of the boot in said vertical plane about the toe through an angle smaller than said predetermined angle combined with forward pivoting of the ankle cuff portion relative to the base portion about said pivotal axis.

9. The combination of claim 8, wherein said releasable retaining means is in the form of a socket member, and wherein said means at the lower end of the rod is a ball member engageable with said socket member.

11. The combination of claim 8, wherein the means projecting rearwardly from the ankle cuff portion are spaced upper and lower extensions thereof each having a bore therein, said bores being aligned so as to define together said slideway, and wherein said spring means is retained between the upper side of said lower extension and a stop member on said shaft portion.