Technical Field
[0001] The present invention is related to a safety pin lock system for quick coupler used
in construction equipment.
Background Art
[0002] In the conventional technology of excavators, quick coupler is mounted at the end
of arm and grapples an attachment. It has a hook on front side and hydraulic actuating
wedges on rear side. When the rear side wedge is not engaged properly, the quick coupler
can drop the attachment and it is very dangerous. By locking the front pin when the
rear wedge is extended, dropping an attachment accident can be prevented.
[0003] US Pat. Pub. No. 2014/0294497 A1 discloses a quick coupler for holding an implement which includes a frame having
first and second plates. The quick coupler includes a locking system adapted to lock
the implement in the first and second plates. The locking system includes securing
latch member and hydraulic actuator connected to the latch member which is configured
to move along a guide between the first and second plates. The locking system also
includes a set of grooves provided on the securing latch member and a guide. The set
of grooves are adapted to lock the securing latch member in a latched position. However,
in case of power-off, the quick coupler stops working. Also there is no emergency
release mechanism whenever something go wrong and quick release is needed.
AU 2013 205 373 Al discloses a similar quick coupler.
[0004] This invention is to improve the shortcomings listed above.
Disclosure of Invention
Technical Problem
[0005] The invention's objective is to provide a safety lock system for front pin in a quick
coupler, particularly used for excavators. Another objective is to provide a front
pin safety lock system that works even when power off situation.
[0006] The objects are achieved by the features of the independent claim. The other claims
and the description disclose advantageous embodiments of the invention.
Solution to Problem
[0007] According to first aspect of the invention, a quick coupler apparatus comprising
body (10), pivot pin (101) attached to the body (10), locking arm (100) pivotally
attached to the pivot rod (101), actuator (120) comprising a cylinder (121) and a
piston rod (122) which moves in the cylinder (121), rear wedge (130) attached to the
piston rod (122) and locking guide (110) attached to the rear wedge (130).
[0008] Moreover, the quick coupler apparatus's locking guide (110) further comprising release
wedge (111) for moving the locking arm (100) into a released status when inserted
underneath the locking arm, and locking stopper (112) for maintaining the locking
arm (100) to a locked status when positioned above the locking arm.
[0009] Also, the quick coupler apparatus's locking guide (110) is U-shaped.
[0010] Also, the quick coupler apparatus further comprising release wedge (311) and the
wedge is configured to be connected to the locking guide.
[0011] Another aspect of the invention, a quick coupler apparatus comprising body (20),
front pin lock (201) configured to rotate pivotally to lock in a pin, slide ratchet
(200) configured to move forward-backward to force the front pin lock to rotate, actuator
(220) comprising a cylinder (221) and a piston rod (222) which moves in the cylinder
(221), rear lock (230) connected to the piston rod, links configured to connect the
rear lock and the slide ratchet, and casing (240) configured to house a part of the
links and a part of the slide ratchet.
[0012] Also, the quick coupler further comprising pivotal rod (241) protruded from the casing.
[0013] Also, the quick coupler apparatus's links comprising a first link (211), a second
link (212) and a third link (213) and the first link and the second link are movably
joined by first link joint (215), and the second link and the third link are movably
joined by second link joint (216).
[0014] Also, the quick coupler further comprising protruded pin (243) configured on the
surface of the rear lock (230), and rear lock stroke hole (214) configured within
the first link.
[0015] Also, the quick coupler's second link (212) is connected with the pivotal rod (241)
by rod pin (242).
[0016] Also, the quick coupler's length ratio from the first link joint to pivotal rod and
from the pivotal rod to the second link joint is 1 : n. (wherein, n > 0 and n is real
number)
[0017] Also, the quick coupler further comprising first spring (250) configured to connect
the front pin lock and the body and second spring (251) placed inside of the casing.
[0018] Also, the quick coupler further comprising emergency release handler (280) for releasing
the front pin quickly.
Brief Description of Drawings
[0019] The present invention together with the above-mentioned and other objects and advantages
may best be understood from the following detailed description of the embodiments,
but not restricted to the embodiments, wherein is shown:
Fig. 1, 2 Quick coupler with front pin safety system according to the first preferred
embodiment of the invention from perspective view (Fig. 1) and front the front view
(Fig. 2) when the front pin lock is in released status.
Fig. 3, 4 Quick coupler with front pin safety system according to the first preferred
embodiment of the invention from perspective view (Fig. 3) and front the front view
(Fig. 4) when the front pin lock is in locked status.
Fig. 5 Detailed view of the locking guide for the first embodiment.
Fig. 6 Quick coupler with front pin safety system according to the second preferred
embodiment of the invention from perspective view.
Fig. 7 Quick coupler with front pin safety system according to the second preferred
embodiment of the invention from front view when the front pin lock is in locked status.
Fig. 8 Quick coupler with front pin safety system according to the second preferred
embodiment of the invention from front view when the front pin lock is in released
status.
Fig. 9 Quick coupler with front pin safety system according to the state of art.
Fig. 10 Quick coupler with front pin safety system according to the state of art from
front view when the front pin lock is in released status.
Fig. 11 Quick coupler with front pin safety system according to the state of art from
front view when the front pin lock is in locked status.
Mode for the Invention
[0020] The detailed structure and working mechanics for this invention will be explained
with figures.
[0021] Throughout this specification, a 'locked status' is a status when a bucket or any
attachment attached to the arm of a certain construction equipment (i.e. an excavator)
is locked to the arm so that it does not fall from the arm when the arm is raised
from the ground and a 'released status' is a status when a bucket or any attachment
attached to the arm of a certain construction equipment (i.e. an excavator) can be
removed from the arm or freely fall from the arm when the arm is raised from the ground.
[0022] Figures 1 to 5 are describing the first embodiment.
[0023] In Fig 1, the front pin safety lock system comprises locking arm (100) and locking
guide (110). The locking arm exercises pivotal movement by the pivot pin (101) and
the locking arm's position is determined by the locking guide.
[0024] The actuator (120) is placed in the center of the locking guide and it exerts the
power to lock or release the invention's lock system. The actuator comprises cylinder
(121) and the piston rod (122) to actuate the movement. By the piston rod's backward
movement (backward is a direction from the front pin area (191) from the rear pin
area (190)), the rear wedge (130) is moving backward along with the piston rod and
the locking guide attached to the rear wedge also moves backwards and this leads to
a locked status of the lock system.
[0025] Fig 2 shows the locked status of the lock system. The rear wedge moves backwards
until the piston rod's maximum extension range and can hold one of the pins of the
bucket or other attachment. By the rear wedge's movement the locking guide moves backwards
along with the rear wedge and its locking stopper (112) moves backwards also and it
positions the locking arm in locked status.
[0026] The shape of the locking arm is such that when it is in locked status, the pin of
a bucket or other attachment is prevented from sliding out by its protruding tip (100',
in dotted circle).
[0027] In Fig 5, the locking guide for 1st embodiment is shown in detail. The locking guide
may comprise release wedge (111) and locking stopper (112). The locking guide's structure
is U-shaped with the part of "underscore '_‴ comprises locking stopper (112) and the
two pillar-like parts ("I") in the 'U' both have release wedge (111). Each structure's
usage will be explained with Figures 3 & 4.
[0028] In Fig 3, the actuator (120)'s piston rod (121) moves into the cylinder (121) in
forward direction (forward is a direction from the rear pin area (190) to the front
pin area (191)) so the rear wedge, which is connected to the piston rod, also moves
in forward direction. In this case, the rear wedge is in released status because there
is nothing that keeps the pin from slipping from the locked status.
[0029] In Fig 4 the locking guide, which is connected to the rear wedge, also moves in forward
direction. The release wedge (111), when locking guide (110) moves along with the
piston rod and rear wedge, also moves and inserted into underneath of the locking
arm. Therefore, the locking arm's protruding tip (100') is lowered, making the front
pin area (191) open i.e. a released status. At the same time, locking stopper (112)
moves deep into the locking arm, leaving end tip (100") placed in the center of the
locking stopper (112) so that the locking arm is in released status.
[0030] In Fig 2 the actuator's cylinder pushes the piston rod out in the backward direction
the rear wedge moves backward along with the piston rod. In this case the rear pin
area becomes locked status. The locking guide connected to the rear wedge also moves
backward. The release wedge also moves backwards and is pulled out from the underneath
of the locking arm. At the same time the also backwardly moved locking stopper is
positioned in a region where the end tip (100") is placed at the beam of the locking
stopper, pushing it down. When the end tip (100") is pushed down, the protruding tip
(100') is pivotally rotating upward to make the front pin area closed so that the
lock status is realized.
[0031] This way, the apparatus is exercising the pin locking and releasing mechanism.
[0032] Figures 6 to 8 are descriptions of the second embodiment.
[0033] Fig 6 shows the overview of the second embodiment of the apparatus.
[0034] In this second embodiment, the body (30) of this apparatus comprises an actuator
(320), rear wedge (330), the locking guide (310) and the locking arm (300). The actuator
may comprise a cylinder (321) and a piston rod (322). The piston rod (322) may be
connected to rear wedge (330) and each of the locking guide (310) is connected to
the rear wedge. Release wedge (311) is connected to the locking guide (310) by link
joint (312). The locking arm (300) is attached pivotally movable to the body with
a pivot pin (301). The release wedge (311) is shaped in a way that the thickness is
thin toward the rear wedge but it gradually increases toward the locking arm (300).
[0035] The locking arm (300) equipped with a spring (301') at the pivot pin (301) so that
the contact tip (300') is always pushed downward by the spring (301')'s elasticity.
[0036] Fig 7 shows when this apparatus is in a locked status in second embodiment. When
the front and rear pins are within the range of front pin area (391) and rear pin
area (390) respectively, is attached to the body (30) with a pivot pin (301) and it
can pivotally rotate with the pivot pin (301) in the center. When cylinder (321) of
the actuator (320) pushes out the piston rod (322) backwards, the rear wedge (330)
connected to the piston rod (322) also moves backwards therefore placing the rear
wedge in locked status. At the same time, the locking guide, connected to the rear
wedge also moves backwards. The locking arm connected to the locking guide also moves
backwards. The shape of the release wedge (311) and the spring (301') of the locking
arm make the locking arm's contact tip to gradually move upward following the surface
of the release wedge. While the contact tip is moving upward, the opposite tip (300")
is moving downward and by this movement the locking arm is in locked status, locking
the front pin area.
[0037] In Fig 8, when trying to change the attachment or the bucket, the actuator's piston
rod moves into the cylinder (i.e. forward direction). By this movement, the rear wedge
moves forward along with the piston rod, rendering the rear wedge in a released status.
[0038] Also, the locking guide (310), connected to the rear wedge, moves along with it in
forward direction and the release wedge (311) does too. By the shape of the release
wedge and the spring (301')'s elasticity, the locking arm's contact tip moves down
following the surface of the release wedge. At the same time, the opposite tip moves
up, rendering the locking arm in a released status.
[0039] Figures 9 to 11 are descriptions for an example according to the state of art.
[0040] Forward direction means a direction from the rear pin area (290) to the front pin
area (291) and backward direction means a direction from the front pin area (291)
to the rear pin area (290).
[0041] In this embodiment, the apparatus comprises a body (20), an actuator (220) comprising
cylinder (221) and piston rod (222), rear lock (230) connected to the piston rod (222),
slide ratchet (200) configured to move front pin lock (201) that is configured to
lock the front pin in the front pin area (291), links (211, 212, 213) that connect
the rear lock (230) and the slide ratchet (200).
[0042] The slide ratchet (200) is shaped so that it may push the front pin lock (201) in
forward direction when the actuator is activated and the piston rod is pushed in backward
direction. In this case the front pin lock is positioned to a released status. (because
the front pin lock is open to the forward direction) A spring (250) may be installed
at the front pin lock (201) so that when no outer force is engaged, the front pin
lock (201) is in locked status (i.e. the front pin lock is closed). A front pivot
pin (202) is installed so that the front pin lock (201) is rotationally configured
in the body (200).
[0043] The links (211, 212, 213) are joined by link joints (215, 216) respectively. At the
slide ratchet (200)'s rear pin area (290) direction end, the link (213) is connected
to the link (212) with the link joint (216). A casing (240) covers part of the link
(213) and the slide ratchet (200) with a hold which lets the link (213) move forward
and backward directions. A pivotal rod (241) is configured at the end the casing (240)
and rod pin (242) is connecting the link (212) and the pivotal rod (241).
[0044] A spring (251) may be installed in the casing so that it touches the casing's backward
direction wall and the slide ratchet. This spring (251) may exert elastic force to
keep the slide ratchet's position in place. Another spring (250) may connect between
the front pin lock (201) and an appropriate place in the body (20). The spring (250)
may place the front pin lock (201) in place, i. e. keep the front pin lock (201) closed
for locked status.
[0045] Fig 10 describes when the example front pin lock (201) is in released status (open).
[0046] As the piston rod (222) moves to the backward direction, the first link (211) connected
to the piston rod (222) also moves to the backward direction. The second link (212),
rotatably fixed by the rod pin (242), rotates in counter-clockwise direction. The
second link joint (216) moves in forward direction along with the third link (213).
[0047] The slide ratchet (200) moves forward direction along with the third link so that
the front pin lock (201) opens to be in released status. The spring (250) may keep
the front pin lock (201) in contact with the slide ratchet (200).
[0048] Fig 11 describes when the example front pin lock (201) is in locked status (close).
[0049] As the piston rod (222) moves to the backward direction, the first link (211) connected
to the piston rod (222) also moves to the backward direction. The second link (212),
rotatably fixed by the rod pin (242), rotates in clockwise direction. The second link
joint (216) moves in backward direction along with the third link (213).
[0050] The slide ratchet (200) moves backward direction along with the third link (213)
so that the front pin lock (201) closes to be in locked status. The spring (250) may
keep the front pin lock (201) in contact with the slide ratchet (200).
[0051] The rear lock stroke hole (214) can be configured in the first link (211). When this
stroke hole is in the first link, the first link is connected to the rear lock (230)
with protruded pin(s) (243).
[0052] The protruded pin (243) is on the surface of the rear lock (230) and it is positioned
inside the stroke hole (214) and when the rear lock moves the protruded pin also moves
with the rear lock.
[0053] This stroke hole (214) and the protruded pin (243) can provide a slack in the movement
of the front pin lock (201).
[0054] When the piston rod (222) moves forward or backward, the rear lock (230) moves at
the same time. However, the links (e.g. the first link (211)) do not move until the
protruded pin (243) meets the end of the hole. Until the encounter, the links do not
move.
[0055] This slight 'lack of movement' gives some stroke slack to this apparatus because
if all the components in this apparatus move with the piston rod immediately, there
can be some shortcomings due to the extra-sensitivity from it.
[0056] The second link (212) has a fixed rotation center in the middle (rod pin, 242). The
rod pin divides the second link in a certain way. For maximum efficiency and prolonging
parts life, the length ration can be varied.
[0057] The length ratio from the first link joint (215) to the pin rod (242) to from the
pin rod (242) to the second link joint (216) is 1 : n, wherein n is a positive real
number.
[0058] However, if the ratio is too big (for example, n is smaller than 1) the first link
(211) should move long enough to get the slide ratchet (200) move enough so that the
front pin lock (201) can open (i.e. released status). This long movement sometimes
can lead into malfunction.
[0059] On the contrary, if the ratio is too small (for example, n is much bigger than 1)
the first link (211) may move just a little to get the slide ratchet move for released
status. But, it would require so much force to move the slide ratchet when front pin
is attached so the links, especially the second link and then the first link are under
too heavy pressure every time they move. This can lead into snapping and dangerous.
[0060] So, good length ratio for maximizing the efficiency and prolonging part life is important.
[0061] For better changing the ratio for supporting each work's characteristics, the second
link (212) has multiple puncture holes in it.
[0062] This front lock mechanism is mechanical not electrical or electronic, so the front
lock system works when even power cut off (i.e., no hydraulic power).
[0063] For emergency, the emergency release handler (280) may be manipulated so that the
second link joint (216) ejects from its position. In this case, the spring (251) exerts
its force to the slide ratchet (200) to release the front pin in spite of the spring
(250).
Explanation of reference numbers
[0064]
10, 20, 30: Body
100, 300: Locking arm
100': Protruding tip
100": End tip
101, 301: Pivot pin
101', 301': Spring
110, 310: Locking guide
111,311: Release wedge
112: Locking stopper
120, 220,320: Actuator
121, 221, 321: Cylinder
122,222, 322: Piston rod
130, 330: Rear wedge
190, 290, 390: Rear pin area
191, 291, 391: Front pin area
200: Slide ratchet
201: Front pin lock
202: Front pivot pin
250, 251: Spring
211, 212, 213: Link
214: Rear lock stroke hole
215, 216, 312: Link joint
230: Rear lock
240: Casing
241: Pivotal rod
242: Rod pin
280: Emergency release handle
300': Contact tip
300": Opposite tip