WO1998036654A1

WO1998036654A1 - Quick-release ice crampon

Info

Publication number: WO1998036654A1
Application number: PCT/GB1998/000549
Authority: WO
Inventors: James Lundy
Original assignee: James Lundy
Priority date: 1997-02-20
Filing date: 1998-02-20
Publication date: 1998-08-27
Also published as: AU6300698A; GB9703526D0

Abstract

A quick-release crampon consists of a spiked sole plate (2) and heel plate (3) which are connected by a link bar (4). The sole plate (2) has a toe bar (6) which engages the toe portion of a climbing boot. The heel plate (3) has a heel clamp (7) which engages the heel portion of a boot. The locking mechanism of the crampon comprises a lever (10) pivotally connected to the sole plate (2) and eccentric engaging means for engaging the heel plate (3). The eccentric engaging means comprises a linking member (4) pivotally connected at one end (11) to the lever (10) and at the other end (13) to the heel plate (3). The linking member (4) is adjustable so that the same crampon (1) may be used with boots of different length. The front teeth of the crampon are T-shaped in cross section and comprise a planar V-shaped flange portion (19) and a perpendicular web portion (20) with serrations (21).

Description

Quick-Release Ice Crampon

This invention relates to crampons for mounting on climbing boots to enable boots to be used in climbing on ice and packed snow. In particular the invention relates to quick-release crampons which can be easily secured to and released from the soles of climbing boots.

Prior art crampons are generally made from pressed mild steel. A flat sheet of steel is cut to shape by stamping or other cutting process . The teeth of the crampon are formed by bending projecting parts of the mild steel plate through 90°. The crampons are attached to the boots by one or more straps.

Prior art crampons have the following disadvantages: - the mild steel teeth do not perform well at sub-zero temperatures and may snap off when high loads are applied to them, such as when the weight of a climber is held by one tooth; - mild steel is usually painted to present an attractive appearance, but the paint is quickly scratched and worn off by contact with rocks and ice, resulting in rapid rusting of the crampons; - putting on and taking off crampons is a time- consuming business, because straps have to be done up and undone, all of which can be very difficult when wearing gloves or mittens in sub-zero conditions.

It is an object of the present invention to overcome one or more of the aforementioned disadvantages.

According to a first aspect of the invention there is provided a crampon for attachment to the sole of a boot comprising at least a first plate having one or more toothed portions adapted to engage in ice and projecting from said plate, wherein at least one projecting toothed portion comprises a pointed generally planar member and a rib portion connected to the planar member and extending generally perpendicular thereto.

Preferably the crampon is of metal and the rib portion is welded to the planar member. Preferably the rib portion extends underneath the first plate, and is connected thereto, preferably by welding.

Preferably the rib portion has one or more serrations at its free edge. Preferably the rib portion has a varying depth and tapers towards the pointed end of the planar member.

Preferably the crampon is of steel, most preferably stainless steel.

According to a second embodiment of the invention there is provided a crampon for attachment to the sole of a boot comprising a sole plate and a heel plate, at least one of said sole plate and said heel plate having one or more toothed portions adapted to engage in ice and projecting from said plate, the crampon further comprising a lever pivotally connected to one of said sole plate and said heel plate and provided with eccentric engaging means for engaging the other of said sole plate and said heel plate.

Preferably the eccentric engaging means comprises a pivoted connection.

Preferably the eccentric engaging means comprises a linking member pivotally connected at a first location to the lever and at a second location to the other of said sole plate and said heel plate.

Preferably the length of the linking member between the first and second locations is adjustable. Preferably the linking member is provided with a plurality of holes, through one of which a pivot member connects the linking member to the other of said sole plate and said heel plate. Preferably the pivot member is a releasable fastening member such as a nut and bolt.

Preferably the lever is adapted to abut an abutting portion of the crampon in a first closed position, such that movement of the sole plate away from the heel plate causes said lever to move towards said abutting portion. Preferably the eccentric engaging means is adapted such that movement of the lever away from said abutting portion causes the sole plate first to move towards the heel plate and then to move away from the heel plate such that the sole of a boot may be removed from said sole and heel plates.

Preferably said lever comprises a substantially planar plate member. The plate member may have a handle portion which projects out of the plane of the plate member. Preferably the handle portion extends generally perpendicular to the plane of the plate member. The handle portion may be formed by twisting a portion of the planar plate member.

Preferably the crampon further comprises an adjustable heel clamp and/or a restraining toe bar.

While further modifications and improvements may be made without departing from the scope of the invention, the following is a description of a particular embodiment of the invention, with reference to the accompanying drawings, in which:

Fig. 1 shows a plan view on a crampon according to a first aspect of the invention; Fig. 2 shows a side elevation of the crampon of Fig. 1; Fig. 3 is an enlarged section through line A-A of Fig. 2; Fig. 4 is an enlarged view in the direction B on Fig. 1; Fig. 5 shows a plan view on a crampon according to a second aspect of the invention; and Fig. 6 shows a side elevation of the crampon of Fig. 5.

Figs. 1 and 2 show a crampon 1 according to the invention. The crampon 1 is preferably made of Type 304L Austenitic Stainless Steel, and is formed by cutting and bending steel plate, which typically has a thickness of 2 mm.

The advantages of using stainless steel are that the material is extremely corrosion resistant, the plate material is significantly and rapidly hardened by cold working, and the crampons exhibit excellent toughness and good ductility at lower temperatures. The fatigue resistance increases with decreasing temperatures, and precipitation hardening occurs in the austenitic nuclear matrix during ageing and cold work usage.

With the obvious exception of the centre safety strap, which is not shown, every component part of the crampon 1 is manufactured from stainless steel, resulting in a high quality, corrosion free product of exceptional durability and attractive polished lustre finish. The finish can be restored at any time even after prolonged and severe usage by simple metal polishing.

The crampon consists of a sole plate 2 and a heel plate 3 which are connected by a link bar 4. The sole plate 2 and heel plate 3 have spikes 5 which are formed by bending triangular plate projections through 90°. The spikes 5 provide traction in ice and snow. The sole plate 2 has a toe bar 6 which engages the toe portion of a climbing or walking boot. The heel plate 3 has a heel clamp 7 which engages the heel portion of a boot. The heel clamp 7 may be adjusted in height by means of a bolt 8 which connects the heel clamp 7 to a heel upstand 9 integrally formed with the heel plate 3.

The locking mechanism of the crampon 1 is of the 'over- centre lock' type. Release is facilitated by pivoting the handle 10a of a lever 10 away from the sole plate 2. When the pivot member 11, which links the lever 10 and link bar 4, passes the line between pivots 12 and 13, the sole and heel plates 2, 3 are slid apart from each other and the boot is released. Pivots 12 and 13 may be rivet connections which allow relative rotation of the connected parts. Pivot 12 connects the lever 10 to the sole plate 2 and passes through a slot 14 in the heel plate 3. The slot 14 allows for the use of the same crampon 1 with boots of different length. The lever 10 consists of a plate portion 10b through which pivots 11 and 12 pass and a handle 10a. The handle 10a is formed by twisting a portion of the plate from which the lever is made through 90°.

The procedure is reversed for fitting. The natural resilience of the sole of the boot, which is in compression, holds the crampon 1 itself in tension and keeps the mechanism in the locked position. In the locked position the handle 10a abuts an abutting portion 5' of the sole plate 2. In the example shown the abutting portion 5' is part of one of the teeth of the crampon, but in practice it can be any part of the sole plate 2. Similarly it may be another part of the lever 10, and not the handle 10a, which abuts the sole plate 2.

The handle 10a may be operated even when wearing mittens or gloves, a vital requirement at high altitudes and low temperatures. The link bar 4 has several holes 15 drilled in it to allow for accurate fit of different boot sizes. The nut and locking bolt of pivot 13 allow relative rotation of the link bar 4 and the heel plate 3. In use the nut and locking bolt 13 are only undone when the crampon is used on boots of a different size. It is not necessary to undo the bolt 13 when taking the crampon on and off.

An optional centre safety strap (not shown) secures the instep of the boot firmly down onto the crampon 1, a particularly important feature when using leather as opposed to plastic boots, and also acts as a secondary security device to ensure the handle is kept in the locking position under heavy impact, since the strap passes around the dogleg portion 16 of the handle 10 to hold it in contact with the sole plate 2. Fig. 4 shows the retaining slot 17 formed in a flange 18 on the underside of the sole plate 2. The flange is formed by bending a rectangular projecting portion of the sole plate 2 through 90°. The strap is passed through and held by the retaining slot 17.

The heel clamp 7 is height adjustable for varying boot sole thicknesses. The heel clamp 7 is fastened to the projecting rearward flange 9 of the heel plate 3 by means of a fastening bolt and locking nut 8. The flange 9 may be provided with a number of holes or a slot to allow for adjustment of the height of the heel clamp 7. It is not necessary to undo the bolt 8 when taking the crampons off. It is only necessary to undo the bolt when adjusting the crampon 1 for use with boots having a different sole thickness.

Fig. 3 shows the T-shaped front tooth 19 which ensures maximum grip on high-angle or vertical faces. The vertical serrated teeth 21 are formed in a web 20 which is seam welded to the tooth 19 by a stainless wire- spool method using inert argon gas as the weld shield. Pre-heating and post-weld cooling enhance the natural precipitation hardening qualities of the steel in the area of the toe teeth resulting in a strong and resilient structure able to withstand the most strenuous abuse and impact.

The sole plate 2 is provided with a cutout hole 21 to reduce weight. Similarly the heel plate 3 is provided with two cutout holes 22 to reduce weight. Upstands 23, formed by bending projecting portions of the heel plate through 90°, hold the heel of a boot centrally in the heel plate 3.

Referring now to Figs. 5 and 6, the same reference signs are used to denote the same components as shown in Figs 1 and 2. The vertical webs 30 of the front teeth 19 extend along the length of the sole plate 2, improving stiffness of the sole plate 2, and serving as guide walls for the neck portion 34 of the heel plate 3. The planar nature of the webs 30 makes them easier to fabricate. The slots 17 for the strap (not shown) are formed in lateral portions 31 of the sole plate itself 2. Both the sole plate 2 and heel plate 3 are provided with a large number of small holes 32, 33 to reduce weight.

The high build quality and material suitability and integrity result in a product with a prolonged life span and inherently good safety features to satisfy the needs of the most demanding climbers.

The T-shaped section of the front teeth 19 has a high inertia and gives improved bending resistance, making the teeth 19 less likely to snap off under extreme load.

One crampon 1 can fit a range of boot sizes, but the fitting and release operation remains simple, being accomplished by moving one lever 10. Fitting and release can therefore be accomplished while wearing mittens or gloves.

Accidental operation of the lever 10 can be prevented by a single strap which also serves to hold the instep of the boot firmly down onto the crampon. A strap with an easily operable release mechanism may be chosen, so that the crampon is still quickly and easily releasable from the boot.

Although in the illustrated embodiments the lever 10 is pivotally connected to the sole plate 2, while the link bar 4 is pivotally connected to the heel plate 3, it is possible and equally effective to arrange the eccentric connection such that the lever 10 is pivotally connected to the heel plate 3, and the link bar 4 is pivotally connected to the sole plate 2. The slot 14 would then be provided in the sole plate 2 , which would fit beneath the heel plate 3.

These and other modifications and improvements can be incorporated without departing from the scope of the invention.

Claims

1. A crampon (1) for attachment to the sole of a boot comprising a sole plate (2) and a heel plate (3) , at least one of said sole plate and said heel plate having one or more toothed portions (5) adapted to engage in ice and projecting from said plate (2, 3), the crampon further comprising a lever (10) pivotally connected to one of said sole plate and said heel plate and provided with eccentric engaging means (4, 11, 13) for engaging the other of said sole plate and said heel plate.

2. A crampon according to Claim 1 wherein the eccentric engaging means comprises a linking member (4) pivotally connected at a first location (11) to the lever (10) and at a second location (13) to the other of said sole plate and said heel plate.

3. A crampon according to Claim 2 wherein the length of the linking member (4) between the first and second locations is adjustable.

4. A crampon according to Claim 3 wherein the linking member (4) is provided with a plurality of holes (15), through one of which a pivot member (13) connects the linking member to the other of said sole plate and said heel plate.

5. A crampon according to Claim 4 wherein the pivot member (13) is a releasable fastening member such as a nut and bolt.

6. A crampon according to any of Claims 1 to 5 wherein the lever (10) is adapted to abut an abutting portion (5') of the crampon in a first closed position, such that movement of the sole plate (2) away from the heel plate (3) causes said lever (10) to move towards said abutting portion (5').

7. A crampon according to any of Claims 1 to 6 wherein the eccentric engaging means is adapted such that movement of the lever (10) away from said abutting portion (5') causes the sole plate (2) first to move towards the heel plate (3) and then to move away from the heel plate (3) such that the sole of a boot may be removed from said sole and heel plates .

8. A crampon according to any of Claims 1 to 7 wherein said lever (10) comprises a substantially planar plate member (10b) and a handle portion (10a) which extends generally perpendicular to the plane of the plate member (10b) .

9. A crampon according to any of Claims 1 to 8 wherein the crampon further comprises an adjustable heel clamp (7) and/or a restraining toe bar (6) .

10. A crampon according to any of Claims 1 to 9 wherein at least one of said projecting toothed portions comprises a pointed generally planar member (19) and a rib portion (20, 30) connected to the planar member and extending generally perpendicular thereto.

11. A crampon for attachment to the sole of a boot comprising at least a first plate (2, 3) having one or more toothed portions (5) adapted to engage in ice and projecting from said plate, wherein at least one projecting toothed portion comprises a pointed generally planar member (19) and a rib portion (20, 30) connected to the planar member and extending generally perpendicular thereto.

12. A crampon according to one of Claims 10 and 11 wherein the crampon (1) is of metal and the rib portion (20, 30) is welded to the planar member (19) .

13. A crampon according to one of Claims 10 to 12 wherein the rib portion (20, 30) extends underneath the first plate (2, 3), and is connected thereto.

14. A crampon according one of Claims 10 to 13 wherein the rib portion (20, 30) has one or more serrations (21, 31) at its free edge.

15. A crampon according to one of Claims 10 to 14 wherein the rib portion (20, 30) has a varying depth and tapers towards the pointed end of the planar member (19) .