BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates to a hoist, and more particularly to a hoist for quickly
lifting and positioning an object to a suitable height and having a simple structure.
2. Description of Related Art
[0002] A conventional hoist in accordance with the prior art usually has a complicated structure
that needs a lot of time for manufacturing. However, the manpower cost becomes high
day by day. The manufacturer must simplify the structure of the conventional hoist
to decrease the manufacturing cost and effectively enhance the effect of the conventional
hoist.
[0003] The present invention has arisen to mitigate and/or obviate the disadvantages of
the conventional hoist.
SUMMARY OF THE INVENTION
[0004] The main objective of the present invention is to provide an improved hoist for quickly
lifting and positioning an object to a suitable height and having a simple structure.
[0005] To achieve the objective, the hoist in accordance with the present invention comprises
a mast and multiple legs connected to the mast for standing the mast. A fixed pulley
is mounted on a top end of the mast. At least two first cables is driven by a controlling
device, and has a first end connected to the controlling device and a second end secured
on a lower end of a telescopic post that is partially slidably received in the mast.
A pulley is mounted to an upper end of the telescopic post. At least two second cables
each has a first end secured on a top of the mast and a second end secured on a lower
end of a telescopic rod that is partially slidably received in the telescopic post.
Consequently, the hoist of the present invention has a simplified structure for reducing
the manufacturing cost. The telescopic post and the telescopic rod simultaneously
upwardly extend so that the hoist of the present invention can quickly lift the object
to a suitable height.
[0006] Further benefits and advantages of the present invention will become apparent after
a careful reading of the detailed description with appropriate reference to the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007]
Fig. 1 is a perspective view of a hoist for lifting and positioning an object to a
suitable height in accordance with the present invention;
Fig. 2 is a partially cross-section view of the hoist in Fig. 1;
Fig. 3 is an operational top plan view of a controlling device of the hoist in accordance
with the present invention; and
Fig. 4 is an operational view of a reel of the hoist in accordance with the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0008] Referring to the drawings and initially to Figs. 1-4, a hoist for quickly lifting
and positioning an object to a suitable height in accordance with the present invention
comprises a mast (10) that is hollow. A slider (11) is movably sleeved around the
mast (10). Multiple legs (12) each includes a first end pivotally connected to the
slider (11) by a first pivot (13) and a second end having a roller (17) mounted thereon
for easily moving the hoist of the present invention. The mast (10) includes a lower
end having a connecting seat (14) mounted thereon. A stretcher (15) includes a first
end pivotally connected to the connecting seat (14) and a second end pivotally connected
to a corresponding one of the multiple legs (12) by a second pivot (16) so that the
multiple legs (12) is foldable relative to the mast (10).
[0009] A fixing member (110) is mounted to the slider (11) to selectively hold the slider
(11) in place on the mast (10). In the preferred embodiment of the present invention,
the fixing member (110) is a screw and securely abutting an outer periphery of the
mast (10) after being screwed through the slider (11).
[0010] A stopper (18) includes a first end pivotally connected to the connecting seat (14)
and a second end adapted to push a supporting surface to prevent the hoist of the
present invention from an unexpected movement.
[0011] An operating arm (20) has a first end pivotally connected to a top of the mask (10)
by a third pivot (21) and multiple positioning holes (22) laterally defined in the
operating arm (20).
[0012] A linkage (23) has a first end pivotally connected to the mast (10), and a second
end extending into the operating arm (20) and aligning with a corresponding one of
the multiple positioning holes (22). A wedge (24) extends through the corresponding
positioning hole (22) and the second end of the linkage (23) to hole the second end
of the linkage (23) in place and adjust an elevation of the operating arm (20).
[0013] A telescopic post (30) partially received in the mast (10) and longitudinally moved
relative to the mast (10). The telescopic post (30) includes a lower end received
in the mast (10) and having an end piece (not numbered) attached thereon. The end
piece abuts an inner periphery of the mast (10) to prevent the telescopic post (30)
from being wavered. A fixed pulley (31) is mounted to a top end of the mast (10).
[0014] A controlling device (40) is mounted in a second end of the operating arm (20) opposite
to the mast (10). The controlling device (40) includes a shaft (41) laterally extending
through the controlling device (40) and having a threaded portion (42) formed on the
shaft (41) after extending through the controlling device (40). A drive gear (44)
is mounted around the threaded portion (42), a brake pad (46) is mounted around the
threaded portion (42) and a washer (45) is mounted between the drive gear (44) and
the brake pad (46). The drive gear (44), the washer (45) and the brake pad (46) can
be laterally moved on the shaft (41) due to the threaded portion (42). A ratchet wheel
(43) is mounted on the threaded portion (42) to prevent the washer (45) and the brake
pad (46) from detaching from the shaft (41). A crank (411) is mounted on the shaft
(41) for driving the ratchet wheel (43) and the drive gear (44).
[0015] A pawl (47) is pivotally mounted to the controlling device (40) by an axle (48) for
selectively being engaged to the ratchet wheel (43) to make the ratchet wheel only
rotate in a single direction and a torsion spring (49) is mounted around the axle
(48) for providing a restitution force to the pawl (47).
[0016] A reel (50) is pivotally mounted in the controlling device (40). A driven gear (51)
is laterally mounted to one end of the reel (50) and engaged to the drive gear (44)
so that the reel (50) is rotated when the crank (411) is circularly operated.
[0017] At least two first cables (52) each has a first end secured on the reel (50) and
a second end secured on a bottom end (32) of the telescopic post (30) after detouring
on the fixed pulley (31) so that the telescopic post (30) is moved relative to the
mast (10) when the reel (50) is rotated to reel the at least two first cables (52).
[0018] A telescopic rod (60) is partially and slidably received in the telescopic post (30).
The telescopic rod (60) includes a lower end slidably received in the telescopic post
(30) and an upper end having adapted to support and lift an object. An end piece (not
numbered) is attached to the lower end of the telescopic rod (60) and abuts an inner
periphery of the telescopic post (30) to prevent the telescopic rod from being wavered.
[0019] A pulley (61) is mounted on an upper end of the telescopic post (30). At least two
second cables (62) each has a first end secured on a top end (64) of the mast (10)
and a second end secured on the bottom end (63) of the telescopic rod (60) after detouring
the pulley (61) so that the telescopic rod (60) upwardly extends when the two second
cables (62) are pulled and the telescopic post (30) upwardly extends.
[0020] When operating the hoist in accordance with the present invention, the user only
needs to rotate the crank (411) for driving the drive gear (44), the driven gear (51)
and the reel (50), thereby reeling the at least two first cables (52) on the reel
(50) to upwardly moved the telescopic post (30). At the same time, the at least two
second cables (62) upwardly move the telescopic rod (60) because each second cable
has a second end secured on the lower end of the telescopic rod (60) and a first end
secured on the upper end of the mast (10), and is detoured on the second pulley (61)
that is mounted to the upper end of the telescopic post (30). As described above,
the telescopic post (30) and the telescopic rod (60) upwardly extend at the same time
so that the hoist of the present invention can quickly lift the object to a suitable
height.
[0021] When stopping operating or the object being lifted to a suitable height, the user
only needs to let go the crank (411), and the first cables (52) and the second cables
(62) reversely pull the reel (50) due to the gravity. Consequently, the driven gear
(51) reversely drives the drive gear (44) to laterally push the washer (45) and the
brake pad (46) toward the ratchet wheel (43) due to the threaded portion (42) of the
shaft (41). The telescopic post (30) and the telescopic rod (60) are fixed when the
brake pad (46) laterally abuts the ratchet wheel (43) and the pawl (47) can prevent
the ratchet wheel from being reversely rotated. Consequently, the hoist of the present
invention can effectively position the object on a suitable height.
[0022] As shown in the figures of the preferred embodiment of the present invention, the
hoist of the present invention has two first cables (52) and two second cables (62)
so that the present invention has no immediate danger when one of the two first/second
cables (52/62) is broken. Consequently, the security of the hoist is enhanced. In
addition, the two first cables (52) and the two second cables (62) are respectively
connected to the telescopic post (30) and the telescopic rod (60) and do not extending
through the telescopic post (30) and the telescopic rod (60) so that the telescopic
post (30) and the telescopic rod (60) can maintain the completeness of the structures
of the telescopic post (30) and the telescopic rod (60).
[0023] As described above, the hoist of the present invention comprises a simplified structure
for reducing the manufacturing cost. The telescopic post (30) and the telescopic rod
(60) simultaneously upwardly extend so that the hoist of the present invention can
quickly lift the object to a suitable height, and the pawl (47) only allows the ratchet
wheel being rotated in a single direction so that the present invention can effectively
positioning the object at the suitable height.
[0024] Although the invention has been explained in relation to its preferred embodiment,
it is to be understood that many other possible modifications and variations can be
made without departing from the spirit and scope of the invention as hereinafter claimed.
1. A hoist for quickly lifting and positioning an object to a suitable height comprising:
a hollow mast having multiple legs pivotally connected to the mast for standing the
mast, a fixed pulley mounted to a top end of the mast;
an operating arm having a first end pivotally connected to a top of the mask;
a linkage having a first end pivotally connected to the mast and a second end connected
to the operating arm for supporting the operating arm;
a telescopic post partially received in the mast and longitudinally moved relative
to the mast, the telescopic post having a lower end received in the mast;
a controlling device mounted in a second end of the operating arm opposite to the
mast, the controlling device including a shaft laterally extending through the controlling
device and having a threaded portion formed on the shaft, a drive gear and a brake
pad mounted around the threaded portion, the drive gear and the brake pad can be laterally
moved on the shaft due to the threaded portion, a ratchet wheel mounted on the threaded
portion to prevent the brake pad from detaching from the shaft and the brake pad being
situated between the ratchet wheel and the drive gear, a crank mounted on the shaft
for driving the ratchet wheel and the drive gear;
a pawl pivotally mounted to the controlling device for selectively being engaged
to the ratchet wheel to make the ratchet wheel only rotate in a single direction;
a reel pivotally mounted in the controlling device, a driven gear laterally mounted
to one end of the reel and engaged to the driven gear so that the reel is rotated
when the crank is circularly operated;
at least two first cables each having a first end secured on the reel and a second
end secured on a bottom end of the telescopic post after detouring on the fixed pulley
so that the telescopic post is moved relative to the mast when the reel is rotated
to reel the at least two first cables;
a telescopic rod partially and slidably received in the telescopic post, the telescopic
rod including a lower end slidably received in the telescopic post and an upper end
adapted to support and lift an object; and
a pulley mounted on an upper end of the telescopic post and at least two second
cables each having a first end secured on a top end of the mast and a second end secured
on the lower end of the telescopic rod after detouring the pulley so that the telescopic
rod upwardly extends when the two second cables are pulled and the telescopic post
upwardly extends.
2. The hoist as claimed in claim 1, wherein the operating arm comprises multiple positioning
holes laterally defined therein and the second end of the linkage extending to aligning
with a corresponding one of the multiple positioning holes, a wedge extending the
corresponding one of the multiple positioning holes and the second end of the linkage
for adjusting an elevation of the operating arm.
3. The hoist as claimed in claim 1 further comprising a stopper including a first end
pivotally connected to a lower end of the mast and a second end adapted to push a
supporting surface to prevent the hoist of the present invention from an unexpected
movement.