Note: Descriptions are shown in the official language in which they were submitted.
~ 1 .5 ~' ~ 2
Ladder, kit, and positioning support for ladder
Technical field:
The invention relates to ladders with two stringers or
stiles which are connected by rungs and which form a foot end
and an opposite upper application end, and are adapted to
be leaned against wall surfaces.
Ladders are probably amongst ~he oldest aids for work-
men, and more and more for domestic and leisure use as well,
for carrying out quickly small tasks at heights which the
average person cannot reach.
State of the art:
Very many different kinds of ladder are produced.
From for example very simple wooden ladders, aluminium
ladders, stepladders, to complicated ladders for example
combined extension and step ladders. Simple lean-on
ladders have the advantage that positioning them at an
inclination against the wall results in putting the user
at a certain distance from the wall, so that, depending
on the length of the ladder, articles of furniture, or
some body, or for e~ample a strip of garden in a loweI-
corner region between ground and wall are bridged and do
not cause trouble. For lean-on ladders there i9 an opti-
mum angle of lean of about 70, this corresponding to
safety-technology standards and regulations.
The accident risk rises with the height to ~hich the
person using the ladder has to climb, but there are more
particularly especial risks with smooth ground surfaces
and walls, since in such cases there is often only slight
2 ~ 3 2
- 2 -
adhesion, because the contact surfaces on the ladder are
very small and hard. The predominantly vertically acting
forces emanating from the ladder user divide of course into
a vertical force normal to the ground and a horizontal sli-
ding force which, in the event of insufficient adhesion
between ladder end and ground, on for example polished
floors, can result in the ladder slipping away which can be
prevented only by a second person exerting counter-pressure
on the foot end. When carrying out cleaning work on glass
surfaces the risk of ladders slipping off is often obviated
by using pairs of steps, or step ladders, which are inde-
pendent of walls. But on the other hand a step ladder also
has considerable other disadvantages, in fact, since it
has only limited stability, and the working distances when
carrying out work on walls are usually disadvantageous as
well.
Slipping-away~of a ladder at the foot end can be pre-
vented by additional safety measures; on the other hand, ;
sideways slipping-a~ay of the upper application end of a
ladder on the wall is a further danger. Ho~ever the general
experience is that going up ladders does not present great
risks provided that regulations for use are observed: for
example correct angle of lean, examination of ground friction
conditions, considering the nature of the ~.~all surface sa-
tisfactory application of the upper ladder application ends
against vertical surfaces and the lo~er foot ends against
the ground.
Thus, dangers when using ladders result not only from
weight loads but more particularly from the lateral actions
of forces emanating from the activity of the person on the
ladder. The stiles of a ladder are usually of slightly
elastic construction, so that small unevennesses, or where
floor and wall do not precisely form two surfaces at right
21 ~ ~i r~ 3 2
angles, are equalised-out elastically by ladder torsion.
But in many cases it is not possible to eliminate relatively
large deviations in that way. In actual practice, theref-
ore, desirable ideal conditions for the positioning of
ladders are unfortunately not provided, so that the user
often makes risky compromises. For example he or she goes
up the ladder even when only the more or less hard, point-
contact application ena of one stile is bearing against
the wall. The other application end is then constrained by
slight twisting of the ladder, though unsafely, to abut on
the wall. Then especially if the user does not have a good
natural technical sense, an unstable situation develops,
since the action of the user's force co-operates with the
internal~preload of the ladder, with an only limited pressure-
application adhesion. In addition, when such stresses
occur the two foot ends also receive destabilising unfavou-
~/ --o~ls
rable force effects, resulting in danger/ accident situ-
ations.
Further sources of danger lie in the fact that con-
ditions may be disadvantageous to virtually impossible
for positioning ladders in certain space circumstances such
as external and/or internal corners formed by ~alls, and
this is often neglected by ladder users.
A normal ladder also cannot, wi~llout additional secu-
ring arrangements, be leaned on posts or columns of less
than 40 cm diameter. Many acciden~-pre~ention authorities -
and ladder manufacturers issue instruction literature indi-
cating that such risky uses are forbidden, to avoid corr-
esponding considerable risks of accident.
Besides known accident risks, ladder users come up
against a further large problem area, that of damage to
wall and ground or floor surfaces by scratching, rubbing
and pressure marks, for example in the case of delicate
colour coatings, glass, stone, wood surfaces, etc.
Representation of the invention :
The invention had as its object more particularly
to improve safety for ladder users, so that accidents con-
nected therewith can be prevented as far as possible, also
to considerably widen the safe range of possible uses for
lean-on ladders and also to obviate damaging buildings,
without complicating the work carried out standing on lad-
ders or complicating the use of ladders. The in~ention had
a further part-object to make it possible for e~isting lad-
ders to be provided with subsequent equipment, or refitted,
in a simple and safe manner, and for use-specific various
ladder application systems to be interchanged in seconds
within the context of a modular system.
The solution according to the invention is characteri-
sed in that the two upper application ends have pairwise-
arranged bearing contact surfaces which can be effective in ~ -
or brought into two spatial directions.
The inventor perceived that hitherto the problem of
ladders was so to speak seen only in one plane, or in two,
as far as the manufacturer was concerned.
In normal use a lean-on ladder is placed on the ground
and positioned against the wall at an angle of 70. The
ladder is dimensioned in accordance with given loads. The
rest is up to the user.
For special uses it is known to provide at the appli-
cation ends for example screw connections for example accor-
ding to US PS No. 4 143 743. For normal lean-on ladders
the manufacturers did not take into their considerations
the third plane, a transverse plane perpendicular to the
walll although it is precisely in this plane that the most
problems can be eliminated, such as:
- risks of accidents to users,
- damage to objects and articles.
To ensure safe support of the upper application ends
against wall surfaces, simply bearing contact zones acting
- 211 a ~ j ~
-- 5 --
perpendicularly against the wall are not adequate. It is
more particularly preferred according to the inven~ion to
arrange the bearing contact surfaces such that they contact
the wall over a full surface and are constructed for example
as interchangeable intensive-adhesion studs with circular
bearing contact surfaces.
If additional bearing contact surfaces are arranged to
act in other spatial directions it is also possible to
counteract the various forces acting from the work being
performed. It is proposed to arrange the individual bea-
ring contact surfaces in paired/mirror-image situations re-
latively to a plane wall surface and/or to the two surfaces
of an internal and/or external corner, and especially pre-
ferably the bearing contact surfaces are constructed as
adhesion elements whose directionsof action are situated in a
common plane of action - for multifunctional usability for
plane wall surfaces and for internal and external corners.
It has been found, surprisingly, that according to the
invention not only is great additional safety achieved
in normal cases of use against plane wall surfaces but for
the first time, contrary to what is prescribed in the
state of the art hitherto, the use of ladders on internal ~`
and external corners is made possible, and even offers
greater safety than when using ladders on a straight wall.
Many tests have shown a positioning safety even in many
extreme situations such as could not be achieved hitherto
by means of lean-on ladders of known type.
Advanta~eously the common piane of action of the bea-
ring contact surfaces is situated transversely to the two
stiles, or it is adapted to be brought into a transverse
plane which forms an angle of preferably about 110 re-
latively to the stiles. The application ends can be con-
structed as angled-over fixed extensions of the two stiles
and ~he bearing contact surfaces arranged on the application
ends.
2~7~2
- 6 -
The invention also relates to a ladder with two stiles
which form a foot end and an upper lean-on or application
end, and is characterised in that the two stiles comprise
an articulation for a pivot pin in the region of the upper
application ends.
In a further especially advantageous feature of the
invention the application end is constructed as a positio-
ning prop or support which is connectable via the articu- ~
lations to the stiles, the articulations forming preferably -
an axis of rotation parallel to the rungs of the ladder.
In the fitted state the positioning support is angled at
about 110 relatively to the stiles, and is so limited in
both directions of rotation by abutments that it can be `
lifted and lowered readily about the axis of rotation. Tests
have shown that by means of an articulated connection the
user-caused vertical spring moment of a lean on ladder is
oscillated-out, and instead of an adhesion-reducing slip-
ping of the bearing contact surfaces an adhesion-intensive
permanent pressing-on of the bearing contact surfaces is
ensured. As a result, risks of accident or damage to wall
surfaces are reduced or excluded. The bearing contact
surfaces are constructed from individual, preferably inter-
changeable, rubber or plastics-type adhesion elements, for
example as rubber studs. The bearing contact surfaces can
be constructed as round or multi-face shaped elements, the
bearing contact surfaces consisting of individual surface ~
elements directed in various spatial directions. ~ -
According to a further feature it is proposed to con-
struct the application ends as continuations of the two
stiles, which are adjus~able by means of hinge-type arti-
culations into a position angled relatively to the stiles, -
and preferably the two application ends are positioning
supports forming a rotatable unit.
~:':. ','
~ r~ ~ 2
-- 7 --
The invention further relates to a kit for a ladder
having two stiles constituting a foot end and an upper app-
lication end, and is characterised in that the kit compr-
ises at least two transition pieces which in the region
of the application end are connectable to the two stiles,
and preferably have articulations.
Often, new inventions bring actual progress in the
sense that, with an insignificant outlay, considerable
damage, accident risks, trouble etc. could be avoided
and/or rational and economic aspects are massively im-
proved. But since an invention is connected fundamen-
tally with products, all previous old products not having
the new inventiYe quality should be replaced or discar-
ded. Bùt, on rational grounds, in actual practice this is
only done to a small extent, which hinders real technical
progress. In the case of ladders this problem could be
solved in a surprisingly simple way with the idea accor-
ding to the invention of the kit with the central element
comprising two transition pieces which are fixable to the
stiles, assemblable with force-locking connections with
lean-on ladders by means of a pin and hole pattern sys-
tem even over ranges of many different rung spacingsand
rung dimensions. Each transition piece can be of two-
part construction; an articulation head part securely
attachable on or to the stile end, and a second clamping
part adapted to be connected to said articulation head
part and adapted to be clamped fast along the stiles
preferably with respect to a rung. 80 to 90 % of all
existing ladders, or lean-on ladders, can be refitted in
this way. Thus existing ladders retain their material
~alue entirely, and canberefitted with the new ladder
addition system according to the invention by means of
small holes at the two stile ends.
7 ~ 2
-- 8 --
For the basic application function the kit has paired
protective caps made preferably of rubber-type or syn- ,
thetic plastic material type material, these being connec-
table at the articulations by means of rapid-action fas
tenings to the transition pieces and thus the lean-on
ladder.
As a further main element it comprises a positioning
support for a multifunctionally extended ladder use range,
this being connectable via the articulations to the tran-
sition pieces and being constru,cted as a positioning ele-
ment against internal wall corners and ex~ernal wall cor-
-ners and also as an application element for normal walls.
A se,curing element, preferably a rapid clamping ele-
ment, for rapid assembly or disassembly and/or inter-
changing of various positioning supports or protective caps. ~'
The interchangeable modular-type multifunctional
positioning supports usually have preferably for both
stiles pivot pins with surplus length for assembly with
ladders of differing widths.
In an especially advantageous feature of the invention
in the form of a positioning support this is characterised
in that it has a plurality of elastic bearing contact sur-
faces which are arranged on two supporting'arms pairwise
in each case. Preferably there are arranged on each sup-
porting arm at least three elastic b,earing contact surfaces
whose directions of action fo'rm an angle, preferably of '''
twice 45 in each case, constructed as a 3-function head.
It has been found that a lean-on ladder with a posi-
tioning suppo~rt not only provides greater safety for the
user but affords also the quite special advantage of grea-
ter/optimum spacing between ladder and wall in the uppermost
region even with the greater safety achieved.
It is also proposed that the positioning support has a
pivot pin or two pivot pins arranged on the opposite side
7 ~ 2
g
from the bearing contact surfaces, and preferably situ-
ated in a common plane with the bearing contact surfaces.
Advantageously the bearing contact surfaces are con-
structed with variously orientated bearing contact sur-
faces, or as individual studs with an annular bearing con-
tact surface.
In a further advantageous feature the positioning
support, secured movably on a central pivot pin, has four
pivotably secured supporting arms. The four supporting
arms can be brought each by means of 90 locating arrange-
ments integral with the pivot pin into three different po-
sitions and used fivefold-functionally through 45-angled
bearing studs. The preferably soft individual bearing
contact studs are made of rubber and/or soft synthetic
plastic material, so that together with up to 8-fold po-
sitioning surfaces only optimum-reduced and careful press-
ure application forces result against highly vulnerable
backgrounds such as for example glass. Especially prefe-
rably the supporting arms are arranged to be individually
pivotable for a multifunctional use capability on plane
surfaces and/or internal and external wall corners.
In the following the invention will now be described
with the use of a plurality of examples of embodiment with
further details.
Short descrip~,ion of the invention
In the drawings:
; IFig. 1 shjows a classic simple lean-on ladder;
Fig. 2 is a side view of a refitted ladder according
to the invention;
plan
Fig. 2a is a/view thereo~,positioned against a straight
wall;
Fig. 2b is a plan view when the ladder is positioned
against an internal corner;
Fig. 2c is a plan view when the ladder is positioned
against an external corner;
-
-- 10 --
Fig. 3 shows a flat positioning support;
Fig. 3a shows a rubber stud with an annular bearing
contact surface;
Figs. 4, 4a, 4b, 4c show similarly to Figs. 2 a simple
positioning support with fixed angled upper stile ends in
the three basic forms of use;
Figs. 5 and 5a show angled supporting arms which are
connectable securely to the stiles;
Figs. 6 and 6a correspond to Figs. 4, 4a, 4b;
Figs. 7 and 7a show angled supporting arms which are
connected to the stiles by means of a hinge;
Figs. 8 and 8a show angled supporting arms which are
connected to the transi~ion pieces/s~iles by means of a pivot
pin;
Figs. 9, 9a, 9b and 9c show the use of pairwise-
arranged one~piece supporting paws with variously orien-
tated bearing contact surfaces in the three basic kinds of
use;
Figs. 10, lOa, lOb and lOc show similarly to Fig. 9 -~
pairwise-arranged one-piece supporting paws but in cir-
cular-disc form;
Figs. 11, lla, llb and llc show various elements of a
modular system9 especially with a transition piece;
Figs. 12, 12a, 12b and 12c show various positions of
protective caps;
Figs. 13, 13a, 13b9 13CI 13d and 13e show a positioning
support with four supporting arms for surface support.
.': .
Ways!of carrying out the invention
Fig.l shows a conventional simple lean-on ladder 1
which is supported~a a foot- end ,~on a floor 4 by means
of a foot end 2 and is leaned against a flat wall 5 by
means of an upperapplication end 3. The lean-on ladder l
has ~wo stiles 6 and 6' respectively and a plurality of
rungs 7. The stiles 6 and 6' of the lean-on ladder 1 are
7 i 2
leaned at an inclination against the wall 5 at an angle ~
of about 70 to the floor 4. Considered ideally a weight G
corresponding to the weight of a user divides into a
vertical force V and a horizontal force H on the floor, and
an application force AW against the wall 5. The lean-on
ladder 1 is first placed vertically on the floor 4 and then
leaned against the wall 5 parallel to the wall 8 through
a vertical plane 8' through an imaginary central line 9.
The two application ends 3 of the stiles 6 and 6' bring
about the application force AW, these forces acting in sub-
stantially the same directions in a horizontal imaginary
transverse plane 10. The corresponding angle ~ supple-
ments the angle ~ being about 110 relatively to the two
stiles 6 and 6'. When being positioned against and taken
away from the wall 5 the lean-on ladder 1 basically carries
out a movement according to arrow AB. It is assumed that
at least during use the lean-on ladder 1 t or the upper
applicatiOn end 3, carries out no lateral movement S within
the transverse plane 10.
Fig. 2 should now be referred to t this showing an
example of embodiment of the new invention, with the three
most important varieties of use. Fig. 2 is a side view
of a ladder 1 against a wall 5. The ladder 1 is leaned
against the wall 5 via a positioning prop or support 20.
Fig. 2a is a plan view of Fig. 2 and shows the ladder 1
used at a flat vertical wall surface 5. Fig. 2b is also a
plan view on to Fig. 2 but shows the use of the ladder 1
on an internal corner 21 formed by two corresponding wall
surfaces 21' and 21" respectively situated at an angle of
90 to one another. Fig. 2c is a further plan view on to
Fig- 2, showing the ladder 1 used at an external corner
22 which is again formed by two corresponding wall sur-
faces 22' and 22" situated at an angle of 90 relatively
2 ~
- 12 -
to one another.
The positioning support 20 is shown on a larger scaie
in Fig. 3 and comprises two supporting arms 23, 23' res-
pectively which are formed in mirror-image relationship
with respect to a plane of symmetry 24 and are connected
securely by means of screws 25 to form one unit. Arranged
at the two supporting arms 23, 23' respectively are a plu-
rality of bearing contact surfaces 26, which are formed by
individual rubber studs 27. The rubber stud 27 has a di-
rection of action Rl parallel to the vertical plane 8', and
brings about substantially a perpendicular positioning
force AW and is intended for positioning against a flat
wall 5. An example of a rubber stud 27 is shown in per-
spective in Fig. 3a and on a larger scale again. The po-
sitioning force AW is transmitted to the wall 5 via an
annular bearing contact surface 26. Here, normal forces -
AN and friction forces AR resulting from the la~eral force
actions AB, AB' respectively from the user are brought about,
in accordance with the static friction between the material
of the rubber stud 27 and the nature of the wall 5. Thus
the stud 27 takes over very considerable lateral forces
which emanate from the actions of force AB, AB' respect-
iYely. The rubber stud 27 is pressed preferably inter-
changeably into suitable holes 28 in the positioning sup~
port 20. The rubber stud 27' is directed to deviate at an
angle of 45 from the direction of action of the positio-
ning force AW, and is intended as a bearing contact sur-
face 26 ~or an internal corner 21. Here the positionin~
force AW divides into a direction of action R2 and a di-
rection of action R2' offset by 90, over the two sup-
porting arms 23, 23' respectively. It will also be discer-
ned from Fig. 3 that depending on the action of force AB,
or AB' respectiYely by the rules of statics a greate
normal force is exerted either on the left-hand rubber stud
27' or on the right-hand rubber stud 27'. As a result,in
accordance with the increase in the normal force on the
21 ~ ~7~2
- 13 -
rubber stud 27' the friction force increases, and thus
the static friction is increased through the corres-
ponding surface 26. Thus within a normal working action
an increase in the lateral sliding force when using the
ladder in a corner results in increasing the safety level
of the ladder supporting forces. Analogously the force ac-
tions AB in the case of the rubber studs 27" result in an
increase in the ladder supporting forces likewise when
using the ladder at an external corner. To increase
safety the studs 27" can be arranged double in each case.
The rubber studs 27"' come to be used when the ladder l is
positioned against an upright o~ post. The effect in this
case is identical to the action of the rubber studs 27".
In Fig. 3 an irregular line indicates a supporting paw 29
of the supporting arm 23'. At that side of the positioning
supports 20 which is opposite from the rubber studs 27
there are rranged two pivot shafts 30, 30' respectively
with a common axis of rotation 31, these being mounted ro-
tatably by means of supporting bolts 32.
Figs. 4, 4a, 4b and 4c will now be referred to, these
showing analogously to Figs. 2 to 2c the use of a ladder 1
on a flat wall 5 and on an internal corner 21 and external
corner 22 respectively. Here the supporting paws 29 are
identical to the construction shown in Fig. 3. But in
Figs. 4, 4a, 4b, 4c the two supporting paws 29 constitute
a prolongation of the stiles 6, 6' respectively, the app-
-lication end 3 being angled-over at an angle ~ of about
110. The transition arc 40 can be part of the stile pro-
file itself. This solution is especially suitable for
rather short, one-piece, very economically priced ladders~
Figs. 5 and 5a show a variant of Figs. 4, with a posi-
tioning element 20'connected securely to the stiles for
example by screwed connections.
7 5 ~
- 14 -
Figs. 6 and 6a correspond to Fig. 4.
Figs. 7 and 7a have a hinge 41 whicll establishes the
connection of the positioning element 20" to the stiles 6,
6'. The hinge 41 can be put into an extended position
(dashed line) when the ladder is not in use, so that only
a small amount of space is required for storage. In the
angled-over position (full-line position) a stop or abut-
ment 42 secures in the working position.
Figs. 8 and 8a show the use of the positioning sup-
ports 20 in the case of a ladder l with anarrangement faste-
ning by means of the pivot pins 30, 30' respectively. Fig.
8 shows that various ladder widths LB can be connected with
the pivot pins 30, 30', since the corresponding dimensions
Spi and Spa respectively of the pivot pins 30, 30' are de-
signed in accordance with the largest and smallest ladder
widths.
Figs. 9, 9a, 9b and 9c show a simplified form of the
supporting paws 29a, the supporting paw 29a being formed
here of a single body made of rubber or synthetic plastic -~
material. The supporting paw 29a has an inside, front, and
outside bearing contact surface 50, 51, 52 respectively, the
inside bearing contact surface 50 forming an angle ~ of
about 90 relatively to the outside bearing contact surface
52.
In Figs. 10, lOa, lOb and lOc a disc-shaped supporting
paw 29b has been used.
Figs, 11 and lla show the upper application end 3 of a
ladder 1. On each of the two stiles 6, 6' a transition piece
60 is mounted, at the head top and along the inside of the
stiles 6, 6'. Each transition piece 60 consists of a joint
head upper part 61 and a clamping part 62. The joint head
upper part 61 is given a shape adapted to the head top, and
can be secured by means of a cotter pin 63 in the stiles 6,
6' respectively. The clamping part is connected by means of
dogs 64 to the joint head upper part 61, and is clamped by
means of a clamping nut 65 to the joint head upper part 61
against a rung 7. The joint head upper part 61 has at the
- 2~:~5752
- 15 -
end an articulation 66 which is constructed for securing
for example the pivot pins 30, 30', in accordance with Figs.
2 and 3. Each pivot pin 3b, 30' (axis of rotation 31) is
secured against the transition piece 60 by means of a rapid-
action clamping element 67. Fig3. llb, llc and lld have
~three different forms of transition/9pieCciesn68, 68', 68" res-
pectively so t~at the transition piece can also be adapted
to various stile forms and/or types. A rubber abutment 69
is also securely mounted on the transition piece 6(). The
rubber abutment 69 has a double function : firstly it consti-
tutes a non~damaging bearing contact support on a flat wall S,
and secondly the rubber abutment 69 serves as an abut~ent for
the positioning support 20 also (Fig. 2, 2a, 2b, 2c).
Figs. 12, 12a, 12b and 12c show the use of protective
caps 70 which can be mounted on each stile 6, 6' for example
in place of the positioning supports 20, with the same kind
of securing arrangement, by means of rapid-action clamping
elements 67. The protective caps allow the application of
the ladder against highly vulnerable surfaces such as to
avoid damage and protect the transition pieces 60 from fou-
ling.
Figs. 13, 13a to 13e show a face support 80 which in
sn analogous manner to Figs. 2, 2a to 2c, is securable by
means of an axis of rotation 31 or pivot pin 30,30' to the
transition piece of a ladder 1. The face support 80 shows
the double use of the supporting arms which here are arranged
as a pair in each case offset vertically. The upper support
part 81 and lower support part 82 are adjustable by means of
in each case a spacing-pattern pivot 84/85 and secured on
the connecting rod 83. Fig. 13a shows the use of the face
support on a flat wall 5, Fig . 13b on an internal corner,
and Fig. 13c on an external corner. The two support parts
81 and 82 according to a further feature are adapted to
move pivotally about a vertical pivot point 84, 85 respec-
tively outwardly and inwardly. Fig. 13d shows the support
~ ` 21~75~
- 16 -
parts 81 and 82 in the pivoted-in position on a strai&ht
wall 5. Fig. 13e shows the swung-out position wherein the
supporting surface is almost doubled as compared to Fig.
13d. The solutinns of Figs. 13d and 13e are suitable es-
pecially for leaning the ladder directly against glass or
other highly vulnerable surfaces.
. ~
:;
. ~' :
:
~ :~
~ = ~`;
