U.S. patent number 3,786,579 [Application Number 05/327,465] was granted by the patent office on 1974-01-22 for adjustable crampons.
This patent grant is currently assigned to Seattle Manufacturing Corporation. Invention is credited to James R. Clark, Larry R. Gearheard.
United States Patent |
3,786,579 |
Clark , et al. |
January 22, 1974 |
ADJUSTABLE CRAMPONS
Abstract
An adjustable crampon with a frame which is articulated for
width adjustment and has extensible rear frame members for length
adjustment, and is made rigid after being fitted to a given
boot.
Inventors: |
Clark; James R. (Bellevue,
WA), Gearheard; Larry R. (Bellevue, WA) |
Assignee: |
Seattle Manufacturing
Corporation (Bellevue, WA)
|
Family
ID: |
23276656 |
Appl.
No.: |
05/327,465 |
Filed: |
January 29, 1973 |
Current U.S.
Class: |
36/7.6;
36/114 |
Current CPC
Class: |
A43C
15/068 (20130101) |
Current International
Class: |
A43C
15/06 (20060101); A43C 15/00 (20060101); A43b
003/10 () |
Field of
Search: |
;36/2.5R,2.5AJ,7.6,59R,62,64 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Lawson; Patrick D.
Claims
The embodiments of the invention in which a particular property or
privilege is claimed are defined as follows:
1. An adjustable crampon comprising:
a closed four-bar articulated linkage having two front and two rear
bars with integral point elements depending at their outer edges
and the front bars being shaped to generally conform with the
periphery of a boot sole, forwardly of the instep,
length adjusting means for adjusting the length of the two rear
bars,
and adjustable-length cross-link means laterally interconnecting
the two rear bars between said length adjusting means and said
front bars for locking the linkage after the width between the rear
ends of the front bars had been adjusted.
2. An adjustable crampon according to claim 1 in which said
cross-link means has strap connecting means at its opposite ends
and is adjustable in location length-wise of said two rear
bars.
3. An adjustable crampon according to claim 1 in which the two
front bars turn inwardly and overlap at the front, and front
adjustable pivot means between said overlapped portions of the
front bars for selectively varying the distance between the front
bars at the front thereof outwardly of their said portions.
4. An adjustable crampon according to claim 3 in which the two rear
bars turn inwardly and overlap at the rear, and rear adjustable
pivot means between said overlapped portions of the rear bars for
selectively varying the distance between the rear bars at the rear
thereof outwardly of their said portions.
5. An adjustable crampon according to claim 1 in which said front
bars each have a respective upstanding sole engaging post at its
edge near the front thereof and in which said rear bars each have a
respective upstanding heel engaging member near its rear end.
6. An adjustable crampon according to claim 5 in which said
cross-link means has strap connecting means at its outer ends and
in which said posts and heel engaging members also have strap
engaging means.
7. An adjustable crampon according to claim 1 in which the rear end
portions of the front bars overlap the front end portions of the
respective rear bars, a respective pivot element extending through
each set of said overlapped portions, a respective hole in one of
said overlapped portions of each set spaced endwise thereof from
the respective pivot screw and registering with a lateral slot in
the other of said overlapped portion of the set, and a respective
clamping element extending through said hole and registering
slot.
8. An adjustable crampon according to claim 1 in which said bars
are generally flat and overlap the adjoining bars, said rear bars
each comprising a respective rear member and a center member which
overlap one another and have respective sets of holes at the
overlap for selectively receiving fastening elements therethrough
comprising said length adjusting means.
9. An adjustable crampon according to claim 8 in which the sets of
holes in the center members extend forwardly of the rear members
and receive fastening elements passing through respective ends of
said cross-link means.
10. An adjustable crampon according to claim 8 in which said rear
members are on the upper side of their overlap with the center
members, and said center members are on the upper side of their
overlap of the front bars, said cross-link means comprising two
overlapping links which engage the upper side of said center
members.
11. An adjustable crampon comprising:
an elongated open frame assembly providing around its periphery a
plurality of depending points and providing front and rear
upstanding boot engaging means near its opposite ends,
articulating means for selectively varying the central width of the
frame assembly relative to the width of the frame assembly near its
ends,
extensible means in the frame assembly for selectively varying its
length,
and locking means including laterally extending means of adjustable
effective length operatively connected to the frame assembly for
making the crampon rigid after width adjustment.
12. An adjustable crampon according to claim 11 in which said
laterally extending means is adjustable in location endwise of the
frame assembly independently of said extensible means and has
upstanding means at its ends independent of said front and rear
means for connecting to boot attaching means.
Description
BACKGROUND OF THE INVENTION
The present invention relates to adjustable crampons applied to
climbing boots for alpinism, ice climbing, walking on icy surfaces,
and other mountaineering pursuits, and more particularly, relates
to rigid type crampons as distinguished from the hinged type. In
the rigid type the full length of the crampon is a rigid frame,
whereas in the hinged type, shown for example in U.S. Pat. No.
3,685,173, the portions of the crampon beneath the boot heel is
free to flex relative to the portion beneath the sole.
Some rigid type crampons have been made adjustable in the past both
in length and width to accommodate a range of boot sizes and sole
shapes, but the adjustment system has had the drawback of not being
such as to make it possible to adjust for the full expanse of boot
widths in such a manner as to locate the depending point elements
substantially as far out laterally as the extent of the boot sole,
particularly in the region of the widest part of the boot. Such a
point location is vital so that the climber, especially when having
to make footing on a narrow ledge or step, can locate crampon
points close to the inner side of the ledge without interference by
way of engagement of the side of the boot sole with the adjoining
rock or ice wall.
SUMMARY OF THE INVENTION
An important object of the present invention is to eliminate the
above-mentioned drawback in the rigid crampons of the known
adjustable types.
Another object is that of providing an adjustable crampon that is
sturdy and safe to use and yet can be economically produced.
These and further objects which will better appear from the
following description are attained by, in effect, making the frame
of the crampon a closed four-bar articulated linkage that is
adjusted in width by articulating the frame and is locked by a
central cross-link assembly which is adjustable in effective
length. The two rear bars of the linkage are adjustable in length
to adjust the length of the crampon frame and the cross-link
assembly can be positioned at various points along the rear bars to
properly locate central strap posts fixed at the ends of the
assembly. These strap posts complement pairs of front and rear
strap posts upstanding from the four-bar linkage which also has the
crampon points integral therewith.
BRIEF DESCRIPTION OF THE DRAWING
Further characteristics and advantages will appear from the
following detailed description of a crampon embodying the invention
and illustrated by way of example in the accompanying drawing in
which:
FIG. 1 is a bottom perspective view of the crampon in operative
position in a boot shown in phantom;
FIG. 2 is a top plan view of the crampon;
FIG. 3 is a longitudinal vertical sectional view taken along the
line 3--3 of FIG. 2;
FIG. 4 is a detail fragmentary bottom plan view of one of the
center articulations as indicated by line 4--4 in FIG. 3;
FIG. 5 is a transverse cross-sectional view to the rear taken along
the line 5--5 of FIG. 2; and
FIG. 6 is a transverse cross-sectional view to the front taken
along the line 6--6 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, it is seen that for purposes of example
the invention has been shown applied to a 12 point crampon 17
having 10 vertical point elements and two forwardly projecting
front point elements 18-19 shaped downwardly from the horizontal
about 20.degree. . The vertical points comprise a pair 20-21 at the
rear, a pair 22--23 near the front of the heel location, a pair
24-25 at the front of the instep location, a pair 26-27 at the wide
portion of the foot, and a pair 28-29 near the front.
The crampon is provided with three pairs of strap posts 30-31,
32-33 and 34-35 at the rear, center and front, respectively. Each
of these has a slot 36 for receiving a lace style crampon strapping
for holding the crampon onto a boot in the conventional manner. It
will be noted that the rear strap posts 30-31 diverge in the
forward direction to serve as a rear stop for the boot heel and
that the front strap posts converge in the forward direction.
The point elements are integral extensions of rear, center and
front pairs of longitudinal frame members 38-39, 40-41 and 42-43,
respectively, which are interconnected by a pivot screw 44 at the
rear, a two-piece adjustable cross-link 46-47 at the center, and a
pivot screw 48 at the front. Also integral with the rear members
38-39 and front members 42-43 are the rear strap posts 30-31 and
front strap posts 34-35, respectively. The center strap posts 32-33
upstand integrally fron the outer ends of the adjustable center
cross-links 46-47. It is preferred that frame members and
cross-links of the crampon be formed from high strength chrome
molybdenum steel.
For length adjustment of the crampon frame the rear frame members
38-39 are each provided with a longitudinal row of equally spaced
holes 50 from a straight section forwardly of the points 22-23, and
the center frame members 40-41 are perforated along most of their
length with holes 51 spaced apart in like manner to the holes 50.
Two pairs of screws 52-53 and 54-55 passing through mating of the
holes 50, 51 are used to rigidly clamp the center and rear frame
members together in adjusted position with the front portion of the
rear members 38-39 overlapping a rear portion of the center members
40-41.
Width adjustment of the crampon at the front and back is
accomplished by respective sets of matching holes 56 and 57 formed
in lateral front extensions 42a- 43a and rear extensions 38a- 39a.
So that both sides of the crampon will be at the same sole level,
the lateral extensions 38a and 42a are offset downwardly to extend
beneath the extensions 39a and 43a, respectively, as shown in FIGS.
5 and 6. Similarly, the rear end portions of the front members
42-43 are offset downwardly, as indicated at 43a for member 43 in
FIG. 3, to extend beneath the forward end portions of the center
members 40-41 to receive therethrough pivot screws 58-59 and set
screws 60-61 threaded into overlying holes in the center members.
The set screws 60-61 pass through lateral slots 62-63 as best seen
in FIG. 4. It will be noted that the center member 40 may be
straight throughout its length whereas the other center member 41
bends outwardly forwardly of the point element 25 so as to
complement the curved shape of the rear portion of the respective
front member 43.
The center cross-links 46-47 overlap, the cross-link 46 being
downwardly offset at 46a to pass beneath the cross-link 47. The
overlapped portions have respective rows of holes 62-63 along their
length for receiving a center adjusting screw 64 and side adjusting
screws 66-67, the latter two passing through selected of the holes
51 in the center members 40-41. There is a differential spacing
between the two sets of holes 62-63 so that small endwise
adjustments of the center cross-links 46-47 will always place two
of these holes in registration to receive the screw 64.
Of the afore-mentioned complementing sets of holes in the frame
members and center cross-links, the upper sets are tapped from
beneath and the lower sets are clearance holes. The screws are
threaded into their respective holes from the underside to leave
flat top surfaces. It is preferred that the screws be of the allen
head type.
To fit the crampon to a given boot, the width at the front and rear
are first set by adjusting the screws 48 and 44 in the respective
holes 56-57 so that the front points 18-19 project the desired
amount forwardly of the toe of the boot when the boot is jammed
against the front posts 34-35, and so that the rear posts 30-31
bear against the rear rounded corner portions of the heel.
Normally, the front adjustment is made after the center sections
40-41 have been connected to the front sections by the screws 58
through 61, but that is optional. Howbeit, usually the crampon is
next adjusted for length and the locking screws 52 through 55 set
in place to rigidly secure the center and rear members
together.
Then, with the front and rear screws 48 and 44, and the central
screws 58 through 61, all loosened, the crampon frame is
articulated as a four bar closed linkage such as to locate the
points 26-27 beneath the outer edge of the wide part of the boot
sole. Then the fore-going six screws are tightened. To securely
lock this adjustment the cross-links 46-47 are then positioned with
the center strap posts 32-33 at the proper instep location and the
screws 64, 66 and 67 set and tightened in place. With all of the
screws tightened the crampon frame is not only locked against
articulating but is rigid in the vertical direction. This rigidity
is assisted by having central longitudinal ribs 68 formed at the
underside of the front members 42-43.
Summarizing, it can be seen that in its assembled form the crampon
frame comprises a closed four-bar linkage in which the rear member
38 and center member 40 together are a first link, the other rear
member 39 and center member 41 together are a second link, and the
front members 42-43 are the other two links, and in which the four
articulations of the linkage are the screws 44, 48, 58 and 59. The
first and second links, and hence the entire linkage, is locked by
the cross-link assembly 46-47. The effective length of the linkage
is adjusted by varying the lengths of the first two links, and
namely by changing the registration of the sets of holes 50 and 51
and shifting the screws 52 through 54 accordingly. The width across
the widest part of the other two links 42-43 of the four-bar
linkage is varied by laterally expanding or retracting the linkage
by articulating it with the cross-link assembly 46-47 disconnected.
The cross-link assembly not only serves to lock the linkage after
adjustment but also permits ready adjustment of the center strap
posts lengthwise of the crampon.
It is important to note that the design of the parts is such as to
provide production economies. A right foot crampon has been
illustrated in the drawing. For a left foot crampon the rear
elements 38-39 can remain unchanged, and the center cross-links
46-47, center members 40-41 and front members 42-43 need only be
turned over during fabrication and the respective point elements
and posts bent in the opposite directions from the right foot
version. Thus, the present invention not only provides a rigid
crampon with great versatility of adjustment, but also provides a
unit that only requires a minimum of parts and fabrication dies to
manufacture a right and left pair.
From the above description, it is seen that a crampon according to
the present invention can be applied to a large variety of boot
types, sizes and dimensions in a simple, safe and reliable manner
insuring that the point elements 26-27 can always be at least as
far out laterally as the overlying outer edge portions of the
boot.
The invention is susceptible to modifications and changes all of
which fall within the scope of the inventive concepts and ideas.
The materials and dimensions can be varied in accordance with the
requirements.
* * * * *