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Патент USA US3083796

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April 2, 1963A
H. G. ARNOLD
3,083,786
STEPLADDER
Filed Sept. 19. 1961
2 Sheets-Sheet 1
AT TYS.
April 2, 1963
H. G. ARNOLD
‘
Filed Sept. 19, 1961
3,083,785
STEPLADDER
2 Sheets-Skaai'l 2
INVENTOR.
HAROLD G. ARNOLD
ATT YS
United States î‘li’atent
1
2
3,033,786
Harold G. Arnold, Wooster, (lino, assigner to The Bauer
Manufacturing Company, Wooster, Ollio, a corporation
of Ohio
Filed Sept. 19, 1961, Ser. No. 139,294
5 Claims. (Cl. 1232-126)
The present invention relates t0 a lightweight metal
Heretofore it has been known to construct metal step
ladders by riveting the steps directly to the walls of the
side rails. This construction was carried forward to the
brace members between the prop members and to the
Patented Apr.. 2, 1963
tween the top step and the prop members taken on the
line 2-2 of FIG. l.
FIG. 3 shows a section of the gusset reinforcing mem
bers taken along the line 3-3 of FIG. l.
FlG. 4 shows a section of the prop member reinforcing
structure taken along the line 4-4 of FiG. 1.
FIG. 5 is an enlarged perspective view of the tool tray,
in a Slightly tilted position, other portions of the ladder
STEPLADDER
stepladder.
3,083,785
l0
being broken away.
FIG. 6 is an enlarged fragmentary view of the spreader
linkage between the side rails and the prop members.
t FfG. 7 is an enlarged fragmentary perspective view of
the shoe members secured to the side rails.
With specific reference to the form of the invention
pivotal connection between the prop members and the 15 illustrated in the drawings, the numeral 1d (see FlG. 1)
indicates generally a ladder having a pair of metal side
side rails. With this construction the load forces on the
ladder were concentrated on the rivets and the walls of
rails 11 and 12. These rails, and the other portions of
the side rails and prop members adjacent the rivets.
the ladder, as hereinafter described, are usually made
from high strength aluminum or `aluminum alloy. Many
This structure results in a maximum sheer forces on
the rivets and tends to enlarge the holes in the metal side 20 of the ladder parts, such as the rails are conveniently
made by extrusion. The side rails are channel-shaped in
rails and prop members so that they become out of round.
cross section having a web portion 13 and flange portions
ln this condition the ladder is difficult to operate and
impairs the safety of the person on the ladder.
14 and 1S. Extending over the outer portion of the web
are parallel longitudinally extending grooves 16, primarily
In the conventional stepladder the pail shelves are pro
vided with a plain fiat surface. Slight movement of the 25 for purposes of appearance.
ladder may dislodge the pails or tools contained thereon.
A plurality of consecutively shorter step members 17,
These ladders often have the further disadvantage that
1S, 19, 20, and 21, each of inverted channel-shaped sec
when the ladder is in the closed position the tray has
tion, are secured through their flanges by conventional
a tendency to fall open.
rivets 22 at equal vertical intervals to the ilanges of the
It is the general object of the invention to avoid and 30 side rails. The ñanges of the step members are at other
overcome the foregoing and other diiiìculties of and ob
than a right angle with the base web at each step member,
jections to the prior stepladders by the provision of an
so that with the ladder open, as in FIG. 1, the top of
each step member is horizon-tal and the flanges are at
improved durable, strong, and relatively inexpensive
ladder.
the angle of the side rails. Thus the flanges of the side
Another object of the invention is to improve the sta 35 rails 'and of the step members closely and iiatly engage
where riveted together. Additionally, the ends of each
bility and rigidity of a metal step ladder Without substan
tially increasing its weight.
step member are cut at a slight angle to assure a flush
abutment with the web of the side rails. rlfhe taper of
A further object of the invention is to construct a metal
stepladder which does not gall and bind when it is set up.
the side rails (slightly together in a vertical direction)
Still another object of the invention is to construct a 40 determines the angle at which the ends of the step mem
bers are cut. Each step member has a series of longi
metal stepladder with structural shapes which are eili
cient to produce.
tudinally extending grooves 23 and a longitudinally ex
tending rib 24 on »the top side of the web to increase
The aforesaid objects of the invention, and other ob
jects which will become apparent as the description pro 45 the frictional characteristics of the step surface, as best
shown in FIG. 3.
ceeds, are achieved by providing in a metal stepladder
a pair of channel-shaped side rails, a plurality of channel
shaped step members secured in spaced relation within
and to the channel of the side rails, reinforcing gusset
Right and left-‘hand triangular-shaped gusset plates 25
and 251 'are riveted to the outside of the fiange of the first
step member 17 and to the outside flange of the penulti
plates having interlocking dimple and groove formations 50 mate step member 21. Each gusset plate has three bores,
one in each corner. Surrounding the bores in the acute
cooperating with complementary `dimple and rib forma
angles of the plate is a spherical dimple formation 26,
tions in the first step and penultimate step and a flange
as best shown in FIG. 3. The outer flange of the step
member 17 and 21 have complementary dimple forma
cured to the top step with a ball and socket bearing,
spreader means pivotally secured to the prop members 55 tions, and rivets 22 complete the subassembly. The dim
ple formations provide bearing surfaces for the ‘load on
and side rails for holding the prop members in spaced
the step members, but primarily take the loads to hold
relation from the side rails and a box type tray pivot
the ladder rigid laterally. To further increase the struc
ally secured to the upper portion of the prop members
tural rigidity of the assembly the gusset plate is provided
and adapted to engage the lower portion of the penulti
with 1a horizontally extending groove 27 which embraces
mate step when in the open position, and shoe members 60 a rib 28 on the lower portion of the ñange of the step
secured to the bottom portion of each side rail and each
members 17 and 21. An additional purpose of the dimple
prop member.
formations is to make up for a diiference in metal in
A better understanding of the invention will be readily
the riveting operation. At some points there are three
appreciated as the same becomes better understood by
pieces of metal, that is, the channel ñange of the side rail,
reference to the following detailed description when con 65 the thickness of the gusset plate and the flange of the
sidered in Iconnection with the accompanying drawings in
step members through which the rivet must pass to hold
of the side rails, a pair of reinforced prop members se
which like reference numerals designate like parts
throughout the ñgures thereof and wherein:
all three pieces together. At other points there will be
only two thicknesses of metal. The dimple makes up
FIG. 1 is a perspective View of a preferred embodiment 70 for the lacking third thickness to permit the use of the
of the invention.
same length rivet. Dimpling also allows the outermost
FIG. 2 shows a section of the ball and socket joint be
portion of the rivet to be ñush with the outer surface of
3,083,786
3
the ladder thereby improving appearance and eliminating
a protruding rivet head on the front of the step member.
The top step member 29 has a rectangular base 30,
end Walls 31 bend substantially normal to the base and
parallel side walls 32 disposed with respect to the plane
of the base at an oblique angle equal to the slope of
the side rails with the ladder open. r["he top step mem
ber ñts over the upper end portions of the side rail-s and
is riveted or otherwise secured thereto.
Supporting the ladder `in an upright position are a pair 10
of channel-shaped prop members 33 and 34. The prop
members are pivotally 'secured to .the end walls of the top
step `by a ball and socket connection 35, yas best shown
in FIG. 2. Each prop member has an outwardly extend
4
from one end thereof. In this construction, when the link
members are moved from the inverted V with the ladder
closed -to the straight line horizontal position with the
ladder lopen, the hanged end of the flange link lying
beyond the pivot point engages with the link member'
to prevent the link members from moving beyond dead
center. The .opposite ends of the respective angle mem
bers are pivotally secured on pivot pins to stamped
spreader supports 64 and 65. The support 64 is rigidly
secured to the outside llange of the prop member and
the support 65 is rigidly secured to the inside flange of
the side rail. This construction places the spreader
member on the inside of the ladder.
As best shown in FlG. 7, on the lower ends of each
ing spherical dimple formation 36 surrounding a bore. 15 of the pro-p members and the side rails are secured shoe
On each end wall of the top step there is a complementary
elements 66, 67, 68 and 69. Each shoe element has a
outwardly extending dimple lformation 37 surrounding =a
bore.
Each dimple formation has a convex and a con
base plate 7i) that is rectangular in shape and extends
slightly beyond the outer edges of the flange member and
cave surface. Between the convex surface of the dimple
web member of the channel-shaped rail. This structure
formation 36 and the concave surface of the dimple 20 prevents the ends of the flanges from being damaged in
formation 37 is disposed an anti-friction washer 38 which
use. A securing tab 71 projects normally from the upper
may be of nylon or similar material. The action of
surface of the plate member and. lies against the inner
aluminum on `aluminum causes a galling condition in
surface of the web. A conventional rivet or the like 72
which a metal ball will be rolled up by the scratching or
secures the foot member to the end of the rail. A rub
galling of metal on metal. The dimples forming a 25 ber sole 73 is vulcanized, riveted 'or otherwise secured to
pocket for the nylon washer, permit the washer to act as
the underside of. the base plate to provide an increased
a separator at this important pivotal point and eliminate
frictional contact with the ladder supporting surface.
galling. A rivet 39 extends through the bore in the
Since the shoes 68 and 69 on the ends of the prop mem
dimple formations and the washer to pivotally secure the
bers are substantially the same as the shoes 66 and 67,
prop members to the end walls 4of the top step.
30 they are not described in detail.
A plurality of successively shorter channel-shaped brace
Even though it is believed the operation «of the appa
members 40, 41, 42, and 43 ‘are secured through their
bases at spaced intervals by means of rivets 44 to the back
ratus will be apparent from the foregoing description, a
brief review thereof will now be made for purposes of
flange orf the channel-shaped prop members. The entire
summary and simpliñcation. When the stepladder is in
prop member portion of the ladder is additionally rein 35 the folded position the stops S4 on the tray brackets 52
forced against lateral movement with left and right-hand
and 53 prevent the tray 56 from falling open. The step
triangularly 'shaped `gusset plates 45 and 46 secured be
ladder is set up by rotating the prop members 33 and 34
tween members 40 and 43 and the prop members. The
gusset plates 4S and 46 have a ilange 47 `bent at right
about the ball and socket joint 35 in a clockwise direc
tion. When the angular spreader members 6_1 and 62
angles. The flange 47 has -two downwardly extending 40 are in the same horizontal plane the prop members are
dimple formations 48, each surrounding a ybore as best
seen in FIG. 4. The lower flange Iof the channel mem
bers includes a dimple formation 49 surrounding a bore
which is complementary to the -dimple formation 48.
.in a fixed relation to the side rails. The tool tray is then
placed in the open position by rotating it in a counter
clockwise direction.
It should be understood, of course, that the Iforegoing
Extending through the 4bore in the dimple formations are 45 disclosure relates to only a preferred embodiment of the
rivets Sil to rigidly secure the gusset plate to the channel
member. Each gusset plate is provided with a third
dimple formation surrounding `a -bore in the acute angle
thereof. A rivet `51 extends through the bore in the
third dimple formation and a bore in the flange of the 50
prop members to rigidly secure the gusset plate to the
invention, and that it is intended to cover all changes and
modifications of the example of the invention herein
chosen for the purposes of the disclosure, which do not
constitute departures from the spirit and scope of the
invention.
prop member.
To mount a vtray 56 on the ladder, a pair `of supporting
What is claimed is:
1. A stepladder comprising a pair of side rails each
having a web and flanges forming a channel shaped cross
brackets 52 and 53 (FIG. 5) are »rigidly secured l‘by means
section, a plurality of dimple formations surrounding
of rivets or the like to a black flange of each of the prop 55 bores in one of each of the flanges of the side rails, a
members midway Ibetween the top step and the .top chan
plurality of step members having a web and ñanges form
nel member 43. The brackets have a laterally extending
ing a channel shaped cross section, one of the fianges of
ear portion or stop 54 and a normally extending flange
the bottom and penultimate step members having a plu
55 forming an L shape in horizontal section. Pivotally
rality of dimple formations surrounding bores and a rib
secured on pivot pin 551 to the flange 55 is the box type 60 projection, the opposite ends of the step members being
pail and vtool tray 56. The pivotal axis of the tray 56
positioned at spaced intervals in the channels of the side
is slightly above the stop 54. The tool tray has a
rails so that the channels of the step members open in a
rectangular flat »base portion 57 which at its end extends
downward direction, a pair of gusset plates each having
under and engages the penultimate step 21 and which
a plurality of dimple formations surrounding bores com
65
extends an equal distance in the opposite ldirection and
plementary to the dimple formations in the ñanges of the
engages the stops 54. Secured to the edges of the 4base
bottom and penultimate step members and the ilanges of
portion 57 are side flanges 58 and a cross llange 59‘ there
the side rails and having a groove compiementary to the
by `forming a box-like structure.
rib of the flanges »of the step members, means securing the
A pair of folding spreader members 60 are positioned
flanges of the step members to the ñanges of the side
between each side rail and the corresponding prop mem 70 rails, and including means positioned in the bores for se
ber to hol-d the prop members in spaced relation from
curing the gusset plates to the ñanges of the side rail and
the side rails. Each spreader member has a hat link
the flanges of the bottom and penultimate step members,
member 61, a second flanged link member 62 and a pivot
a rectangular shaped top step having a flat base, end walls
pin 63 connecting one end of the first link member to the
substantially normal to the base and side Walls angularly
76
second flanged link member at a point slightly inw-ardly
disposed with respect to the base disposed over the top
3,083,786
5
ends of the side rails, means securing the top portion of
side rails to the end walls of the top step, a pair of prop
members, brace means holding the prop members in sub
stantially parallel relationship, and anti~friction ball and
6
member having a web and ilanges forming a channel
shaped cross section, the flanges of the iirst and second
members having dimple formations surrounding bores, a
rib on one of the flanges of the second member, an end
portion of the second member disposed in the channel of
the first member substantially normal to the web of the
first member, a gusset plate having a plurality of dimple
for-mations surrounding bores complementary to the
the side rails, means pivotally securing the spreader
dimple formations on the flanges and having a groove
means to the prop members and the rail members, bracket
means secured to the upper inside portion of the prop 10 complementary to the rib »on the ílange of the second
socket means pivotally securing the prop members to the
end walls of the top step, folding spreader means for
holding the prop members in a fixed space relation from
members, a tray pivotally secured to the bracket means
and adapted to engage the lower surface of the flanges of
member, and means extending through the bores for se
the penultimate step, shoe means slightly Wider and longer
gether.
than the cross section of the side rails and prop mem
bers, and means securing the shoe means to the base end 15
curing the flanges of the members and gusset plates to~
‘
5. In a stepladder, a pair of side rails, a plurality of
horizontally directed, vertically spaced steps joining the
side rails, a pair of prop members pivotall'y vsecured at
of each of the side rails and prop members.
their upper ends to the side rails near the upper ends
2. A stepladder comprising a pair of extruded metal
thereof, means securing the prop members in parallel re
side rails each having a web and flanges forming a chan
lation to each other, a pair of stamped metal brackets of
nel shaped cross section, a plurality of dimple formations
surrounding bores in one of each of the flanges of the 20 L-shape in horizontal section, each bracket having the
long leg of the L secured to a prop member to position
side rails, a plurality of extruded metal step members
the short leg of the L in a vertical plane directed toward
having a web and ñanges forming a channel shaped cross
the side rail, a metal tray having a ilat base and upstand
section, one of the flanges of the bottom and penultimate
ing side flanges, means pivotally securing opposite side
step members having a plurality of dimple formations
surrounding bores and a rib projection, the opposite ends 25 flanges of the tray to the short leg of the L of each
bracket, said tray having its inner end engaging under a
of the step members being positioned at spaced intervals
step when in horizontal operating position, and an exten
in the channels of the side rails so that the channels of
sion on the long leg of the L of each bracket extending
the step members open in a downward direction, a double
underneath the tray to limit the movement thereof into
pair of gusset plates each having a plurality of dimple
formations surrounding bores complementary to the dim 30 horizontal position, and to take the weight off of the
means pivotally securing the tray to the brackets when
ple formations in the ñanges of the bottom and penulti
the tray is in horizontal operating position.
mate step members and the ñanges of the side rails and
having a groove complementary to the rib of ilanges of
the step members, and means securing the flanges of the
step members to the ilanges of the side rails, and includ 35
ing means positioned in the bores for securing the gusset
plates to the -ñanges of the side rail and the flanges of the
bottom and penultimate step members.
3. The construction described in claim 2 wherein each
step member upwardly from the bottom step is shorter in 40
length than the preceding step member and has its ends
cut at a slight angle complementary to the ladder taper
resulting from the consecutively shorter step members.
4. In a stepladder, a ñrst member having a web and
flanges forming a channel shaped cross section, a second 45
References Cited in the tile of this patent
UNITED STATES PATENTS
1,107,440
1,592,109
2,126,171
Olson ______________ __ Aug. 18, 1914
Jacobs ______________ __ July 13, 1926
'Carbis ______________ __ Aug. 9, 1938
2,235,976
Best ________________ __ Mar. 25, 1941
2,294,333
Fay ________________ __ Aug. 25, 1942
2,533,391
2,899,008
3,005,513
3,016,103
Miller ______________ __ Dec~ 12,
Larson ______________ __ Aug. 11,
Larson ______________ __ Oct. 24,
Studer ________________ _ Jan. 9,
1950
1959
1961
1962
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