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Патент USA US2126805

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‘ Aug. 16, 1938.‘
Filed March 17, 1937
“ 74
2 Sheets-Sheet 1
F085’? 7?. RIIE’KI/l/JO/l/
Patented Aug. 16, 1938
Robert-R. Parkinson and Stuart E. Weaver, Palo
Alto, Calif.
Application March 17, 1937, Serial No. 131,436
1 Claim.
(Cl. 228-17)
This invention relates to step ladders.
The primary object of the invention is to pro
vide an improved step ladder with a folding top
adapted to be unfolded and extended so as to pro
' vide a rigid top of considerable area, means of
connection being provided between the folding.
extensible top and the step ladder to spread the
ladder into open position as the top is unfolded,
and also to automatically engage the top when
10 ‘ fully extended to hold the same rigid.
Other objects and advantages are to provide a
rails T, so that the upper ends of the rails [4
swing toward and away from the upper end of
the supporting member 3. The rails M are con
nected to each other by ?xed braces ll.
upper ends of the rails M are connected by a
tiveness of operation, and facility and con
venience in use and general efficiency.
In this speci?cation and the annexed draw
ings, the invention is illustrated in the form con
sidered to be the best, but it is to be understood
that the invention is not limited to such form,
laterally disposed bar If! which moves below the
under face of the platform or top extension‘8,
and particularly along the bottom of the bars 9.
Onto each bar 9 is attached a wire guide H! to
slidably con?ne the connecting bar l8 between
the bars 9 and the guides 19, thus limiting the
movement of the top extension 8 relatively to the
upper ends of the rails M. Both ends of each
to cover the invention in whatsoever form it may
be embodied.
The invention is clearly illustrated in the ac
companying drawings, whereinFig. 1 is a side view of a step ladder embodying
our invention.
Fig. 3 is an enlarged fragmental side view of
the operating connection between the extension
top and the ladder.
Fig. 4 is a fragmental rear view of the ladder.
Fig. 5 is a plan view of a modi?ed form of
ladder shown in the extended position, and partly
broken away to illustrate the interior construc
tion thereof.
Fig. 6 is a cross section taken thru Fig. 5 on the
line 6-43.
Fig. '7 is a side elevation of the ladder shown in
Fig. 2, the same being in the folded position.
The ladder comprises a step member I, with
steps 2, a supporting member 3 for supporting the
step member, a top 4, and interlocking braces 5
“ for bracing the step and supporting members,
which parts are common to and constitute an
ordinary step ladder.
On the sides at the top of the step member I
are mounted angle iron members 6 secured to the
member I and to the underside of the top 4 re
spectively, thereby ?xedly mounting the top 4
on the top of the member I.
In the rear corners
of the angle iron members 6, the upper ends of
legs ‘I of the supporting member 3 are pivoted
55 at l2.
guide I9 are fastened to the respective bars 9, so as
to prevent the connecting bar l8 and the rails
M from completely separating from the exten
SiOl’l 8.
When the extension 8 is unfolded the bar I8
slides outwardly on the guides l9 and is also pulled
upwardly so as to exert an upward and outward
Fig. 2 is a side view of the ladder folded up.
respective angle irons 6.
A platform support I3 is constructed of a pair of
rails M pivotally connected at the lower ends I6
thereof to the lower ends of the respective support
simplicity, inexpensiveness of construction, posi
it is also to be understood that in and by the
claim following the description, it is desired
tended as at H, and the extended ends H piv
oted on the pivots i2, or at any point on the
step ladder that will be superior in point of
‘ because it may be embodied in other forms; and
A top extension, or platform 8, has bars 9 ?xed
on its under face, one end of each bar being ex
pull on the lower ends of the legs ‘I causing the
latter to swing outwardly around the upper pivots 30
Adjacent the outer ends of the bars 9 are down
wardly extended stops 2| with inclined sides. The
sides of the stops 2| facing toward the top 4
are of a long cam-like incline and the sides 22
of the stops 2| facing rearwardly of the ladder
are abrupt to prevent the connecting bar l8 from
folding up when weight is placed on the top ex
tension B. Thus the platform support I3 is
rendered rigid automatically when the top exten
sion 8 is fully extended. The guides I9 are bent
downwardly below the stops 2| to accommodate
the bar l8 when the same is passed over the
stops 2!.
The weight of the top extension 8 holds the 45
stops in obstruction of the connecting bar 18 and
the more weight that is put on the extension 8,
the more rigid the support [3 becomes. This ar
rangement also prevents the accidental folding of
the step ladder proper, because the supporting
member l3 cannot be swung without the move
ment of the top of the support 13 relatively to the
top extension 3.
In order to fold the ladder, the top extension
8 is slightly raised to allow the connecting bar 55
| 8 to pass beneath the stops 2| and then the
extension 8 is folded over the supporting mem
35, we have provided a gravity actuated member
43 which is pivoted at 44 to the underside of
ber 3. During the folding of the extension 8 the
the platform extension 35, whereby, when the
latter is in the extended position shown in Fig.
3, the free end 45 of the member 43 will drop
down behind the cross bar 42 to prevent it from
bar |8 slides on the bars 9 toward the inner ends
of the guides l9, allowing the folding of the sup
porting member 3 and the step member | to
sliding along the guide 39.
The braces 5 of the step ladder 8, are ar
ranged in pairs and are pivoted at the outer ends
thereof to the respective rails or legs of the step
member I and of the supporting member 3. The
In order to fold or collapse the ladder, the
gravity locking member 43 is elevated manually
from a position behind the cross bar 42, enabling 10
the cross bar and supporting legs 40 to be moved
inner adjacent ends of the respective braces 5
along the guideway toward the step section 30,
are pivoted to each other. The central or meet
ing pivots of the opposed sets of braces 5 are.
which action permits the extension platform 35
to drop into the folded position shown in Fig. 3.
When the ladder is in the folded position, the 15
15 connected to each other by a connecting element
23 formed into a hand grip to facilitate the car
rying and manipulating of the step ladder.
In the modi?ed form of ladder shown in Figs.
5, 6, and 7, we provide a step member 30, sup
20 porting member 3|, the top 32, the angle mem
bers 33, each joining the top to the step mem
ber, and the pivot 34 for pivotally connecting
the supporting member 3| to the angle member
33. An extension platform 35 is provided with
25 bars 36 on its under side.
A plate 31 is secured
to each bar 36, each plate having an extended
end 38 hingedly journaled at its extreme end on
the pivot 34.
A wire guide 39 is arranged below each bar 36,
and in spaced relation thereto, each guide be
ing secured at one end to the under side of the
platform 35, and at the other end to the pivot
Legs 40 are provided for supporting the
platform 35 in the extended position, said legs
35 being hingedly connected at their bottom ends
to the bottom ends of the respective supporting
members 3|, in substantially the same manner
as that set forth with respect to the correspond
ing parts in the preferred form of the invention.
The upper ends of the platform supporting legs
40 are connected by a laterally disposed bar 42,
said bar being slidably con?ned in the‘ space be
tween the bars 35 and the guide wire 39.
When the platform 35 is in the extended posi
tion shown in Fig. 2, the cross bar 42 on the
supporting legs 40 rests against the outer end of
the guide wire 39, and supports the platform 35
in a position parallel to the top 32. To prevent
buckling or folding of the platform extension
supporting legs 40 for the platform extension
are adapted to assume a position alongside of
the supporting member 3 to form a compactly
folded structure.
Having thus described this invention, what we
claim and desire to secure by Letters Patent is:
In a step ladder the combination with a step
member having steps and a top ?xed thereon, a
supporting member pivoted to the step member
below the top, and interlocking foldable braces
to brace the step and the supporting members
in the unfolded position; of an extension plat
form pivotally secured to the step member at
the said top; platform supporting rails pivoted
to the said supporting member and extended up 3O
wardly to the underside of the platform; a con
necting element on the upper ends of the rails;
of wire guides on the underside of the platform
extending toward the outer free edge of said
platform being spaced from the underside of the
platform to slidably con?ne the connecting ele
ment on the underside of the platform; the ends
of the guides being closed to prevent the removal
of the connecting member therefrom; stops ex
tended from the underside of the platform adapt 40
ed to allow the said connecting member to pass
over the stops outwardly but to be held in ob
structing position by the weight of the platform,
after the latter is brought into extended posi
tion, thereby to prevent the collapsing of the said 45
rails unless the platform is lifted and folded.
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