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Патент USA US2405848

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Aug» 13, E94;
G. QUAYLE
LIFT TRUCK
Filed Dec. 11, 1942
4 Sheets-Sheet 1’
.INN
$.91?
INVENTOR
‘BY/W
ATLTOIRNEY
E3, wéa,
G. QUAYLE .
LIFT TRUCK
Filed Dec.\ll ,
1942
r 4 Sheets-Sheet 2
‘Aug’ ' 33' 19464
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' ~
. G.
~LIFT
QUAYLE.
TRUCK
Filed Dec. 11-, 1942
I ' 7
2,45;
4 Sheets-Sheet s,
INVEN-TOR
62
If,
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ATTORNEY
Aug. 13, 1946.
G. QUAYLE
LIFT TRUCK
Fil‘ed Dec. 11, 1942
_4 Sheets-*SHeet 4
'
IN'YENTDR
Géafgé
ATTORNEY
.
,
Patented Aug. 13, 1946
2,405,848
UNITED STATES PATENT OFFICE
2,405,848
LIFT TRUCK
George Quayle, Philadelphia, Pa., assignor to The
Yale & Towne Manufacturing Company, Stam
ford, Conn., a corporation of Connecticut
Application December 11, 1942, Serial No. 468,715
25 Claims.
1
This invention relates to an industrial truck of
the type having an elevating platform adapted to
be raised relatively to a lifting head by the oper
ation of a lifting mechanism.
More particularly my invention relates to a
truck of the type disclosed in, the Schroeder ap
plication 457,729, ?led September 9, 1942, now
Patent No. 2,367,061, dated January 9, 1945.
The industrial truck to which my invention is
(Cl. 254-2)
2
vated positions. As a more speci?c feature of my
invention, the said holding means comprises a
holding shaft, part of which is formed for coop
eration with the holding bar or holding ratchet.
It is a still further feature of my invention that
the holding shaft may be rotated to n roll‘ the
ratchet bar out of holding relation therewith
whereby to release the elevating platform for
lowering movement.
shown applied, is of that type having a lifting
A further feature of my invention resides in a
head and a platform that is pivoted at its for
novel form of treadle whereby the holding shaft
ward end to the lifting head by upper and lower
is rotatable only after some predetermined move
links, so that the platform may be elevated rela
ment of the treadle independently of the holding
tively to the lifting head by pivotal movement on
shaft. As a still further feature of my invention
the said links. The rear end of the elevating 15 this predetermined movement of the treadle prior
platform is supported by wheels that are pivoted
to rotation of the holding shaft, is adapted ‘to
to the platform on links, these links moving to
effect the movement of the lifting means out of
raise the rear end of the platform as the forward
lifting engagement, it being a further feature of
end of the platform is elevated. The particular
this part of my invention to contribute a'free
type of truck outlined is known in the art as a 20 handle to facilitate manipulation of the truck
single frame truck, and it is to this type of truck
where the lifting means of the truck are actuated
that my invention is particularly applicable.
However, as those skilled in art will readily ap
preciate upon the reading of the speci?cation
by the steering handle.
whereby to hold the elevating platform in its elee
understood, Naturally, there are additional fea
Still a further feature of my invention resides
in means for normally maintaining the treadle
that follows, many features of my invention may 25 in a position wherein the holding. means will be
be utilized in other types of industrial trucks, so
effective to hold the truck platform in its ele
that my invention should not be considered as
vated position, with the treadle being adapted for
limited to a single frame truck.
movement automatically into position ,to, effect
As one feature of my invention I employ a
release of the holding means once the treadle is
novel type of lifting link pivoted between the
moved beyond a predetermined position in a
lifting head and the elevating platform, this link
direction to release the holding means. This
bein¢T formed with a series of pins whereby the
feature of my invention is preferably obtained by
rotation of the link may be eifected through a
me through the use of what I term a toggle spring
lifting member that contacts the pins sequen
arrangement, the toggle spring being adapted to
tially to rotate the link in step by step fashion.
urge and to maintain the treadle in one or the
A further feature of my invention resides in
other of two extreme positions as soon as the
holding means for holding the elevating platform
treadle moves to one side or the other of a central
in each of its step by step positions and in its ?nal
or neutral position. Those skilled in the art will
fully elevated position. More in detail this fea
of course appreciate that this portion of my in
ture of my invention resides in the mounting of
vention is of considerable utility in industrial
a holding member preferably on the lifting link,
trucks regardless of the types of lifting mecha
with the holding member being adapted for co
nism or holding means utilized.
operation with cooperative means on the lifting
As still a further feature of my invention I em
head whereby to hold the lifting link in each of
ploy the lowering movement of the elevating plat
its step by step lifting positions.
form to move the treadle beyond its neutral posi
As a further feature of this part of my inven
tion as the elevating platform is lowered, whereby
tion, I utilize a holding member in the form of
to restore the holding means to their holding
a holding ‘bar, or ratchet. bar preferably, this
position, thus enabling the operator to once again
ratchet bar being pivoted to the lifting link for
lift the elevating platform without requiring him
free swinging and cooperative engagement with a
to use manual means for re-setting his holding
holding means on the lifting head.
mechanism.
A further feature of my invention resides in the
I have thus described the more important fea
holding means on the lifting head adapted for co
tures of my invention in order that the operation
operation with the holdingmember or ratchet bar
of the structure of my invention may be better
2,405,848
3
4
tures of my invention that have not been dis
cussed generally but which will be readily under
stood upon a reading of the speci?cations that
follow. Those skilled in the art will fully appre
ciate that the basic features of my invention, both
those described and about to be described, may
supra, and is not per se my invention herein to
be claimed.
Referring now more particularly to Figs. 3, 5, 6
readily be utilized in speci?c forms other than
7 those forms that I shall herein show and describe.
Moreover, many of the features are useful and
valuable per se as well as in combinations. It is
140
and 8, the upper end of the standard I i is pivoted
to the lifting head 15 by an upper link 35, this
upper link being pivoted to the lifting head l5
through the shaft 36, and pivoted to the standard
H. through the shaft 3'1. It is obvious that the
upper link 35 and the lower link 25 form between
.themselves parallel arms for the movement of
' the elevating platform relatively to the lifting
head. The upper link 35 is of novel form per
se, and is part of a novel combination of elements
as will be seen presently.
forms different from those whichI shall herein
There is secured to the link 35 a series of pins
set forth.
'
15
therefore important that the patent claims
granted me shall be suf?ciently broad to prevent
the appropriation of my invention by others in
For a description of my invention I shall refer ~
to the drawings wherein Fig. l. is an’ elevation of
an industrial truck to which my invention has
been applied. Fig. 2 is a plan view of the truck
of Fig. 1. Fig. 3 is a vertical section through the
front end of‘ the truck of Fig. 1. Fig. 4 is an
enlarged view of certain of the parts shown in
Fig. 3 to illustrate their action. Fig. 5 is a View
similar .to Fig. 3 but showing the parts in a dif
38 called lifting pins, and for cooperation with
. these lifting pins I utilize what I term a lifting
pawl 39 having a specially formed portion 40 for
coaction with the pins 38. The lifting pawl 39
is itself pivoted at 90 to a lifting lever M that is
pivoted at 42 on the lifting head iii. A spring
123 is secured at Ad to the lifting pawl 39 and at
9| to the lifting lever 41 and tends to urge the
pawl 39 so that its surface 40 engages the pins 38
as shown in Fig. 3.
ferent position corresponding to full elevation of
For rotating the lifting lever 41 on its pivot
the elevating platform. Fig. 6 is a view of the
42, I use a strut as that is bifurcated at 46 for
parts of Figs. 3 and 5 but showing the platform
cooperation with a pin 4'! of the lifting handle
being lowered. Fig. 7 is a view of certain of the
assembly 18. The upper end of the strut 45 has
parts of Fig. 6 illustrating the operation of those
parts._ Fig. 8 is a section taken along lines 8-8 30 a universal bearing at 48 relatively to the lifting
lever ill, so that in all steering positions of the
of Fig. 3. Fig. 9 is a section taken along lines
lifting handle 18, it is adapted through vertical
9'—.9 of Fig. 3.
reciprocation on its pivot H to rotate the lifting
Referring now more particularlyto the draw
lever M. It is obvious that the particular move
ings and especially Figs. 1 and 2, the elevating
ment will actuate the lifting pawl 39 to rotate the
platform of my truck is designated by reference
link 35 through pins 38.
numeral H} and is formed with a standard ll
For holding the elevating platform in each of
having a forward decorative portion l2 and a
its intermediate elevated positions and in its final
platform that is herein shown as formed of two
elevated position I utilize a holding bar or holding
legs l3 united at the rear by a cross bar M; . The
lifting head of my truck is shown in outline in 46 ratchet, as it may be called, designated by ref
erence numeral 50. The holding ratchet 50 is
Figs. 1 and 2~'and the said outline is de?ned-by
pivoted at 5| to the lifting link 35 so that it has
a series of reference numerals I5 so that the shape
considerable mechanical advantage, being dis
of the lifting head maybe perceived quite readily.
placed a relatively greater distance than pivot
' Rotatable on a vertical bearing in the lifting
shaft 37 from the pivot shaft 36 about which the
head 15 is what is termed a steering head it, to
link 35'is pivoted on lifting head I5. The several
which is pivoted at- H' a steering handle assembly
ratchet teeth 52 of the ratchet bar 56 are adapted
18. The steering head it is adapted toarotate .
for cooperation with the ?attened portion 54 of
relatively to the lifting head l5 and has a pair
the holding shaft 55, and in Fig. 5 the lowermost
of steering wheels l9, it being a function of the
steering handle l8 to rotate the steering head i6 so tooth 52 of the ratchet bar 59 is shown in co
operative engagement With the holding shaft 55
and; its wheels H. The rear supporting wheels
for holding the lifting link 35 in'its fully elevated
of’ the elevating platform are designated by ref
position. Through the ratchet bar 55 the plat
erence numeral 26; These wheels are carried on
form is thus held in its fully elevated position.
an-axle which is secured to lifting links 2| that
The. holding shaft 55 (Fig. 9) is supported in
are pivoted‘ at 22 to the elevating platform l8 1
bearings 55 and 51 relatively to the lifting head
and are movable downwardly by rods 23 as the
l5 and is adapted for rotation by a treadle 58
rods 23 move. to the right. The forward end' of
through a novel type of lazy connection, it being
the elevating platform is pivoted at 24 to lower
the. purpose of the saidlazy connection to allow
links 25 that are in turn pivoted at 26 to the
the treadle 58 to move a predetermined distance
(ii)
lifting head l5. The rods 23 are pivoted at 21
before it imparts movement to the holding shaft
to the links 25 so that as the elevating platform
55. It is. obvious that rotary movement of the
is raised on the links 25 the rods 23 will rotate
holding shaft 55 will be adapted to roll the ratchet
thezlinks 2| to raise the rear end of the platform.
bar 50 away from its position of Fig. 5 and into
A dashpot 3,0 is pivoted. at 3! to the lifting (55 the position of Fig. 6.v In Fig- 6 there is best
head it, and at 32. to the standard‘ H of the ele
shown the positioning of the parts as the plat
vatingplatform Ill whereby to. control the 1ower~
form moves downwardly into its fully lowered
position of Fig. 3 after being released for lower
ing movement of the elevating platform relatively
ing movement.
.
g
to the lifting. head, all as will be understood to
I shall now describe. the lazy connection be
those skilled in the art. It will be well to indi
tween the treadle 58 and the holding shaft 55.
cate at this point that the truck construction
The treadle 58 is formed with a corrugated por
so far outlined in this application is that type of
tion 60 on which may be'placed the foot of the
construction that is now manufactured by The
operator to depress the treadle as will be readily
Yale & Towne Mfg. Co. owner of this applica
seen. The» treadle has a bore Gl- therethrough
tion endowner- of the Schroeder application
2,405,848
5
whereby it may be-mounted for free rotation on
that ?ts about a toggle rod 76, the said toggle
rodbeing slidable through an opening 11 in the
seen from Fig. 9, is integral with the treadle 58
lifting head l5 as is readily seen in Figs. 4, 6
and is-laterally off-set from the main portion of
and 7. The upper end of the toggle rod 18 is
the treadle, forming with said treadle and con
pivoted at 18 to the treadle 58 and a disc 19 ?ts
necting bar 63 a U shaped member.
.
about the toggle rod 15 and accepts the pressure
- What I term a ratchetlcam 64 extends from‘
of the toggle spring 15. So long as the parts are
the bar' 63 of the treadle 58 and also forms an
in the position of Figs. 3 and 4 the spring 15 will
integral part of the said treadle. A pin 85
continue to maintain the parts in that position
traverses a bore 61 of treadle 58, this bore being 10 and the treadle shaft pin 854will contact a limit
somewhat larger in diameter than the bore 56 in
pin 80 for limiting the rotation of the treadle
the treadle shaft 55, and also larger in diameter
58 and shaft 55 by the spring 15. Should the
than the pin 65. Because of this relationship of
treadle be depressed so as to move the toggle rod
pin 65 to the bore 67 of the treadle 58, the treadle
it somewhat to the left of Fig. 4 and beyond a
58 may rotate from its full line position in Fig. 4
dead center position, the spring 15 will then act
to itsdash and dot line position in Fig. 4 before
to rotate the treadle 58 in a clockwise direction
the surfaces of the bore 61 contact the pin 85
to bring it against the limit pin 88 as seen in
to rotate that pin. Therotation of thetreadle
Fig. 7. In other words, the toggle spring 15 is
from its full line position of Fig. 4 to its dash and
effective through the toggle rod ‘l5 and the re
dot line position of Fig. 4 is thus free of the shaft
maining parts set forth to press the treadle into
55, and only thereafter will the continued rota
one or the other of the two extreme positions of
tion of the treadle 58 effect the rotation of the
Figs. 4 and 7, depending on the positioning of the
the holding shaft 55. An arm 82, as may best be
shaft55.
~
This lazy action of the treadle 58 relatively to
theiholding shaft 55 is utilized by me to move
the lifting pawl 39 away from lifting. engage
ment-with one of the pins 38 whereby to con
tribute what is termed in the art a free handle.
treadle on one side or the other of a dead center
~ position.
Because of the particular arrangement set
forth, once the operator presses the treadle 58
from the position of Figs. 3 and 4 and somewhat
beyond the dead center position of the toggle
spring 15 and the toggle rod 15, the toggle spring
‘l5 will thereafter press the treadle into its re
lease position of Fig. 7 and will maintain it in that
release position thereafter. Because of this con
struction of the parts, the operator need not hold
Thus,.those skilled in the art will fully appre
ciate-that in the position of the parts in Fig. 5
the lifting pawl 39 is held away from the lower
most pin 38 so that the lifting handle [8 may
move freely without in any way being in?uenced
bycontact of the lifting pawl 39 with the lower
his foot . on the treadle until the platform is
most'pin 38. This movement of the pawl 39 to 35 lowered in order to insure the continued lowering
the position of Fig. 5 is contributed by treadle 58
of the platform. The operator needs only to de
through its arm 62 and a lever 18 pivoted at Tl
press the treadle beyond a particular point and
to the lifting head l5.> Thus, when the treadle
it thereafter remains fully depressed until the
58 is moved from its full line position of Fig. 4
elevating platform is fully lowered.
to its dotted line position of Fig. 4, which isthe 40
As may be seen in Figs. 3 to '7 inclusive, a lug
same as its full line position of Fig. 5, the arm
82 is secured to the elevating platform standard
62 contacts the lever 10 and rotates that lever
3 i and is adapted to contact the surface 83 of the
18 so that the part 18a of the saidlever contacts
treadle 58 when the platform is lowered. The lug
portion 39a of lifting pawl 39 and effects the
82 is effective to rotate the treadle 58 from its
rotation of- the pawl 39 against the pressure of
position of Fig. '7 to a position beyond the dead
spring 43‘ into the position of Fig. 5. This move
center position of the treadle 58 and the toggle
ment of the lifting pawl 39 may be effected by
rod ‘it, so that the toggle spring '55 may there
the treadle 58 when the platform and the lifting
after rotate the treadle 58 to its initial position
link 35 are in the fully lowered position of Fig. 3
of Fig. 3. The effect of this action is of course to
or in the fully-elevated position of Fig. 5.
'50 restore the treadle 58 and the holding shaft 55 to
It is obvious, of course, that this movement of
the initial holding position of the parts so that
the treadle 58, due to the lazy connection with
the operator may then proceed to elevate the plat
holding shaft 55, has not rotated the holding
form without requiring his operation of any of
shaft 55. This is very important because it is
the parts. This arrangement for automatically
frequently desirable that when the platform is 55 restoring the parts is of great utility in the hand
inits fully raised position, as in Fig. 5, the lifting
lift truck'industry. Under some conditions the
pawl be released from the pin 38 of lifting link
toggle spring '15 may be of only su?icient strength
35 while the holding ratchet 58 remains in hold
to hold the treadle 58 yieldingly in its extreme
ing engagement with the holding shaft 55. Fur
positions after it is moved to said positions, all as
ther rotation of the treadle 58 from its dash and 60 is quite apparent. '
dot line position of Fig. 4 or its full line position
It is Well to emphasize at this point that the
of Fig. 5, will rotate the'holding shaft 55 from
treadle 58, in its normal operation, is adapted
its position of Fig. 5 to its position of Fig. 6
?rst to release the lifting pawl 33 from the pins
whereby to effect a rolling or camming of the
38 of the lifting link 85, and thereafter to release
holding ratchet bar 50 away from the holding 65 the holding means including the holding ratchet
shaft 55 as will be quite readily apparent. The
bar 58 and the holding shaft 55. Because of this
cam 64 that is integral with the treadle 58 is
arrangment of the parts, it is absolutely im
effective to contact the holding ratchet bar 50 to
possible to obtain what is knoWn in the industry
insure its movement from its position of Fig. 5
as a flying handle; that is, a handle that is
to its position of Fig. 6 in the event that the 70 adapted to fly upwardly upon the application
holding shaft is incapable of rolling or camming
thereto of the weight of the elevating platform.
the ratchet bar out of its holding position of
It will also be well for a better understanding of
Fig. 5.
the invention to indictae that the lifting link 35
. The treadle 58 is normally maintained in its
is formed with a shoulder 85, best seen in Figs. 3
position of Figs. 3 and 4 by a toggle spring 15 75 and 5, for engagement with a shoulder tion the
2,405,848
7
lifting head and to an integral part of said ele
vating platform, means whereby step by step lift
movement is imparted to said lifting device to
head. Similarly, a shoulder 31 on the lifting link
35 contacts a connecting bolt 88 on the lifting
head to denote the lower limit of. the elevating
platform and the lifting link 35. It will be well
also to indicate that a spring 89 is utilizedto pre
vent the ?ying movement of the holding ratchet
bar 50 during the lowering'movement of the truck
should that ratchet bar tend to flyupwardly from
8
headian elevating platform, a lifting device
pivoted directly to an integral portion of said
lifting head' t5 tov form. anupper limit to the
elevation of the platform relatively to, the lifting
lift said platform, a holdingmember pivoted to
said lifting device, and a holding surface on said
lifting head over which said holding member
rides as said lifting device is moved step by step,
10
contact with the holding shaft 55 or the, ratchet
cam M.
It will now, be obvious thatv vertical swinging
movement of the lifting handle [8 is adapted,
through the lifting lever 41, to e?ect reciproca
tion ofthe lifting pawl 39 and through that pawl
to rotate the lifting. link 35, from its position of
Fig. 3 to its position of Fig, 5, thereby raising the
elevating'platform Hi. Itlwill also be obvious that
theholding ratchetbar. 5i) will cooperate with the 20
holding shaft 55 to maintain the elevating plat
form raised. Rotation of, the treadle 58 is then
effective to move the lifting'pawl 39 out oflifting
engagement with any one of the pins 38 of the -
lifting link to contribute a free handle I8.
Further rotation of the treadle is effective through
pin 65 to rotate shaft 55 and effect a release of
the holding ratchet bar 50 from, the holding shaft
55- to allow lowering movement of the elevating
said holding member having surfaces cooperable
with said holding surface to hold said lifting
device in each of its step by step positions. 7
5. In a truck of the class described, a lifting
head, an elevating platform, a lifting device,
means whereby said lifting device lifts said plat
form relatively to said lifting head, means where
by step by step lift movement is imparted to said
lifting device to lift said platform, a holding mem
ber pivoted to said lifting device and hanging
loosely downwardly therefrom, and a holding
surface on said lifting head over which said hold
ing member rides as said lifting device is moved
step by step, said holding member having ,sur
faces cooperable with said holding surface to hold
said lifting device in each of its ‘step by step
positions.
6. In a truck of the class described, a lifting
head, an elevating platform, a lifting device,
means whereby said lifting device lifts said plat
platform. The lowering of the elevating platform 30 form relatively to said lifting head, means where
by step by step lift movement is imparted to said
restores treadle 53 to its initial, position as lug 82
lifting device to lift said platform, a holding
contacts surface 83. The automatic operation of
ratchet pivoted at one end to said lifting device,
the toggle rod 15 and its toggle spring T5 for con
and depending freely from said. pivoted end, a
trolling the treadle 58 will. be clearly understood
from the explanation already given.
35 holding surface on said lifting head over which
said holding ratchet rides as said lifting device
I now claim:
is moved step by step, said holding ratchet hav
,1. In a truck of the class described, a wheel
ing ratchet surfaces cooperable with said holding
supported lifting head, an elevating platform
surface to hold said lifting device in each of its
wheel supported at its rear end, a link pivoted by
spaced pivots to said elevating platform and to 40 step by- step positions.
7. In a truck of the class described, a lifting
said lifting head, a lifting device pivoted directly
head, an elevating platform, a lifting device,
to both the platform and the lifting head on
means whereby said lifting device lifts said plat
pivots spaced on a line parallel to the pivots of
form relatively to said lifting head, means where
said link, a series of pins on said lifting device
extending laterally therefrom, and means mov 45 by step by step lift movement is imparted to said
lifting device to lift said platform, a holding
ably mounted on said lifting head and adapted
ratchet pivotally mounted at one end on said
to engage said pins sequentially to actuate said
lifting device, and hanging freely from said piv
lifting device to lift said platform.
otal mounting, a holding surface on said lifting
2. In a truck of the class described, a wheel
head over which said holding ratchet rides as
supported lifting head, an elevating platform
said lifting device is moved step by step, said
wheel supported at its rear end, a link pivoted by
holding ratchet having ratchet surfaces cooper
spaced pivots to said elevating platform and to
able with said holding surface to hold said lifting
said lifting head, a lifting device pivoted directly
device in each of its step by step positions, and
to both the platform and the lifting head on
means for rotating said holding surface whereby
pivots spaced on a line parallel to the pivots of
' to roll said holding ratchet out of holding rela
said link, a series of pins on said lifting device
tion to said holding surface.
extending laterally therefrom, a lifting pawl
8. In a truck of the class described, a lifting
adapted to engage said pins sequentially to
head, an elevating platform, a lifting device,
actuate said lifting device to lift said platform
relatively to said lifting head, and means mov 60 means wherebysaid lifting device lifts said plat
form relatively to said lifting head, means adapt
ably mounting said lifting pawl on said lifting
ed to actuate said lifting device step by step to
lift said elevating platform, a ratchet bar piv
3. m a truck of the class described, a wheel
oted to said lifting device and hanging freely
supported lifting head, an elevating platform
downwardly therefrom, a pawl surface over which
wheel supported at its rear end, upper and lower
said ratchet bar rides as saidlifting device is
links pivoted at one end to said platform and at
actuated, the ratchet teeth of said bar coasting
the other end to said lifting head whereby to as
with said pawl surface‘ to hold. said lifting device
semble said head and platform while mounting
in each of its step by step positions, a shaft of
said platform for upward pivotal movement on
head.
-
'
said lifting head, a series of pins extending later- ‘
which said pawl surface, is a part, and means for
ally from one of said links, and a lifting member
movably mounted on said lifting head and
adapted to engage said pins sequentially to
actuate said link to lift said elevating platform.
rotating said shaft to roll said pawl surface out
of holding relation to the teeth of‘ said ratchet
bar.
9, In a truck of the class described, a lifting
4.,In a truck of the class described, a lifting 75 head, an elevating platform, a lifting device,
r. 2,405,848
9
'10
means whereby said lifting device is connected to
said platform to lift said platform relatively to
said lifting head, means adapted’to actuate said
movably mounted on said lifting head and
adapted to engage and then move said lifting
device step by step to lift said elevating platform,
a ratchet bar pivoted to‘said lifting device, a
pawl surface over which said ratchet bar rides
lifting device step by step to lift said elevating
platform, a ratchet bar pivotally mounted on said
lifting device'at a point where‘ it has considerable
‘mechanical advantage relatively to the means of
connection of said lifting device with said plat
as said lifting device is actuated, the ratchet
teeth of said bar coacting with said pawl surface
to hold said lifting device in each of its step by
form, said ratchet bar depending freely from said
step positions, a shaft of which said pawl ‘surface
pivotal mounting and rotatable on said mounting, 10 is a‘ part, a treadle for rotating said shaft'to
a pawl surface over which said ratchet bar rides
move said pawl surface away from holding rela
as said liftingdevice is actuated, the ratchet
tion to said ratchet bar, and means whereby said
teeth of said bar coacting with said pawl surface
treadle moves said lifting means away from en
to hold said lifting device in each of its step by
gagement with said lifting device before it ro
step positions, and means for rolling said. pawl
' tates said shaft.
surface out of holding relation to the teeth of
15. In a'truck of the class described, an ele
head, an elevating platform, lifting means for
lifting said elevating platform relatively to said
vating platform,v a lifting head, a step by step
lifting ‘mechanism for lifting said elevating plat
form, a holding mechanism for holding said ele
vating platform in its step by step lifted positions
lifting head, holding means for holding said. ele
vating platform lifted relatively to said lifting
comprising a ratchet bar and a holding shaft,
means pivoting said ratchet bar to 'a part of
head, a control shaft for controlling said hold
ing means, a treadle rotatably mounted on said
said step by step lifting mechanism for move
ment therewith as said platform is lifted, said
ratchet bar hanging freely from said part‘ and
riding over said shaft as it 'moves with said part,
and said holding shaft having a portion of its
surface cut away to present a shoulder to ratchet
teeth formed on the surface of said ratchet bar.
said ratchet bar.
-
'
'
10. In a truck of the class described, a lifting
shaft, means operated by said rotatable treadle,
and means whereby said treadle rotates said
shaft after it rotates a predetermined degree
relatively to said shaft.
‘11. In a truck of the class described, a lifting
head, an elevating platform adapted to be lifted 30
16. In a truck of the class described, an ele
relatively to said lifting head,~a control shaft, a
vating platform, a lifting head, holding means
rotatable treadle, means whereby said treadle
rotates said shaft after it rotates a predeter
for holding ‘said elevating platform in a lifted
position relatively to said lifting head, a treadle
for controlling said holding means, a toggle
spring for maintaining said treadle in one posi
mined degree relatively to said shaft, a lifting
device participating functionally in the lifting a
of the ‘elevating platform relatively to said lift
tion, and means whereby the movement of said
ing‘head, a holding device for holding said ele
vating platform lifted relatively to said lifting
treadle a predetermined distance from said posi
tion positions the spring so that it presses said
head, means whereby said treadle moves said
treadle into a second position.
lifting device, and means whereby said shaft ,
moves said holding device.
12. In a truck of the class described, an ele
vating platform, a lifting head, a step by step
lifting mechanism for lifting said elevating plat
form, a holding mechanism for holding said ele
vating platform in its step by step lifted posi
tions comprising a ratchet bar and a holding
shaft, said holding shaft having a portion of its
surface cut away to present a shoulder to the
ratchet teeth formed on said ratchet bar, a
treadle adapted to rotate said holding shaft to
move ‘said shoulder away from holding relation
to said ratchet bar, and a lazy connection be
tween said treadle and said shaft whereby said
treadle moves a predetermined degree prior to ‘
rotating said shaft.
.
13. In a truck of the class described, an ele
‘
'
17. In a truck of the class described, a lifting
head, an elevating platform, lifting means'for
lifting said elevating platform relatively to said
lifting head, holding means for holding saidlele
vating platform lifted relatively to saidlifting
head, a movable control‘ treadle for controlling
said holding means, a toggle spring for maintain
ing said treadle in one position, and means
whereby the movement of said treadle a prede
termined distance from said position positions
the spring so that it presses said treadle into a
second position.
18. In a truck of the class described, an ele
vating platform, a lifting head, holding means
for holding said elevating platform in a lifted
position relatively to said lifting head, a treadle
for controlling said holding means, a toggle
spring for maintaining said treadle in one posi
vating platform, a lifting head, a step by ‘step
lifting mechanism for lifting said elevating plat
tion in which said means are positioned to hold
form, a holding mechanism for holding said ele
it is lifted, and means whereby the movement
of said treadle a predetermined distance from
said position positions the spring so that it
presses said treadle into a second position in
which said holding means are positioned to allow
vating platform in its step by step lifted positions
comprising a ratchet bar and a holding shaft.
said holding shaft having a portion of its sur
face cutaway to present a shoulder to the ratchet
teeth formed on said ratchet bar, a treadle
adapted to rotate said holding shaft to move
said shoulder away from holding relation to said
ratchet bar, and a lazy connection between said
treadle and said shaft whereby said treadle moves
a predetermined degree prior to rotating said
shaft.
said elevating platform in any position to which
lowering of said platform.
19. In a truck of the class described, an ele
vating platform, a lifting head, holding means
for holding said elevating platform in a lifted
position relatively to said lifting head, a treadle
for controlling said’ holding means, a toggle
spring for maintaining said treadle in one posi
14. In a truck of the class described, a lifting
. tion in which said holding means are positioned
head, an elevating platform, a lifting device,
means whereby said lifting device lifts said plat
form relatively to said lifting head, lifting means
to hold said elevating platform in any position
to which vit is lifted, and means whereby the
movement of said treadle a predetermined dis
2,405,848
11
12
tance from said position positions the spring so
- treadle rotates a predetermined degree relatively
- that it presses ‘said treadle into a second position,
to said control shaft, means whereby said treadle
in which said- holding means are positioned to
allow lowering of said platform, and means
‘ moves parts of said lifting mechanism out of en
position.
‘ ing platform, a lifting head, a step by step lifting
gagement, and means whereby said control shaft
whereby the lowering of said platform effects the 5 releases said holding mechanism.
'23. In a truck of the class‘ described, an elevat
movement of said treadle back towards said ?rst
-
mechanism for lifting said elevating platform, a
holding mechanism for holding said elevating
pivotally connecting the front end of said lifting 10 platform in its step by step lifted positions com
prising a ratchet bar and a holding shaft, and a
platform to said lifting head to form a complete
portion of said holding shaft, being cut away to
truck and to mount said lifting platform for
present a shouldered portion to the ratchet teeth
lifting movement relatively to said lifting head,
wheel supporting links pivoted to the rear end
formed on said ratchet bar.
of said platform, means whereby'sthe lifting 15
24. In a truck of ‘the class described, an elevat
ing platform, ‘a liftinghead, a step by step lifting
movement of the front end of said platform rela
mechanism for lifting said elevating platform, a
tively to said lifting head .moves said wheel sup
holding mechanism for holding said elevating
porting links to lift the rear .end of said ‘plat
platform in' its step by step lifted positions :com
form, a movable lifting member mounted on said
prising a ratchet bar and a holding shaft, a
lifting head, means formed on one of said links
portion of said holding shaft ‘being cut away to
engaged by said lifting member for moving said
present a shouldered portion to the ratchet teeth
link whereby to lift the ‘front end of said plat
formed on said ratchet bar, and means for rotat
form relatively to said lifting head, and .a hold
ing said holding shaft’ whereby to roll said
ing member pivoted to said link and adapted to
20. In a truck of the class described, a lifting
head, a lifting platform, upper and lower links
engage holding means on said lifting head for
holding said lifting platform in its lifted position.
'21. In a truck of the class described, a lifting
head, an elevating platform, lifting means for
ratchet bar away from ‘said shouldered portion
of said shaft.
25. In a truck of the class described, a lifting
head, an elevating platform, lifting means for
lifting said elevating platform relatively to said
lifting head, holding means for holding said ele 30 lifting head, holding means for holding said ele
vating platform lifted relatively to said lifting
vating platform lifted relatively to said lifting
head, a control treadle rotatably mountedon a
head, a control shaft for controlling said hold
part of said truck for controlling said lifting and
ing means, a rotatable treadle for rotating said
holding means, a toggle spring for pressing said
control ‘shaft, means operated by said rotatable
treadle, and means of connection between said ; treadle into one or the other of two extreme con
trol positions, and means whereby said spring is
control shaft and treadle whereby said treadle
positioned by rotation of said treadle whereby
rotates said shaft after rotating a predetermined
lifting said elevating platform relatively to Said
degree relatively to said shaft.
' '
22. In a truck of the‘ class described,an elevat
when said toggle spring and treadle are at one
side of a predetermined position said toggle
ing platform, a lifting head, a step by step lifting 40 spring will press said treadle into one of said ex
treme positions, whereas when said treadle and
mechanism for lifting said elevating platform, a
spring are at the other side of said predeter
holding mechanism for holding said elevating
mined position said toggle sprlng will press said
platform in its step by step lifted positions, a
treadle into the other of said extreme positions.
control shaft, a rotatable treadle, means whereby
GEORGE QUAYLE.
said treadle rotates said control shaft after said 45
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