CHAIN HOIST

PALAN A CHAINE

English Abstract

A chain hoist comprising a body (1); a hoist chain (2) passing through the body; through-holes (3, 4) in the body for the hoist chain; and an actuator arrangement (6, 7, 8) for operating the chain hoist, the actuator being used for moving the hoist chain through said through-holes in a lifting or lowering direction of the chain hoist, and on the side of at least one through- hole (3, 4) the portion of the hoist chain (2) moving outside the body (1) is provided with a limiter member whose position in the longitudinal direction of the hoist chain is adjustable, the limiter member being provided with a detectable sensor (11); and a sensor detection member (12) is provided in the vicinity of said through-hole to detect the detectable sensor (11) at a predetermined distance.

French Abstract

Un palan à chaîne comprend un corps (1), une chaîne de palan (2) passant dans le corps, des trous débouchants (3, 4) dans le corps pour la chaîne et une configuration dactionneur (6, 7, 8) pour exploiter le palan à chaîne, lactionneur étant utilisé pour déplacer la chaîne dans les trous débouchants, dans un sens de levage ou dabaissement du palan, et sur le côté dau moins un trou débouchant (3, 4), la partie de la chaîne (2) se déplaçant à lextérieur du corps (1) comprend un limiteur dont la position dans le sens longitudinal de la chaîne est ajustable, le limiteur comportant un capteur détectable (11), et un élément de détection de capteur (12) est fourni à proximité dudit trou débouchant pour détecter le capteur détectable (11) à une distance prédéterminée.

Claims

4
What is claimed is:
1. A chain hoist, comprising:
a body;
a hoist chain passing through the body;
a first through-hole in the body for the hoist chain;
a second through-hole in the body for the hoist chain;
an actuator arrangement for operating the chain hoist, the actuator
being used for moving the hoist chain through said through-holes in a lifting
or
lowering direction of the chain hoist, on the side of at least one through-
hole
the portion of the hoist chain moving outside the body is provided with a
limiter
member whose position in the longitudinal direction of the hoist chain is
adjustable, the limiter member being provided with a detectable sensor; and
a sensor detection member is provided in the vicinity of said through-
hole to detect the detectable sensor at a predetermined distance,
wherein the limiter member has locking members that press resiliently
against the hoist chain, the locking members being locking pins, and
wherein the limiter member is a cylinder with:
an axial through-hole for the hoist chain;
a first transverse hole running through the cylinder and
intersecting the through-hole;
the locking pins being placed into the transverse hole and
pressing against the hoist chain on both sides thereof;
a peripheral groove running on the outer surface of the cylinder at
the transverse hole;
a resilient locking ring placed into the peripheral groove to keep
the locking pins in place in a resilient manner; and
a second transverse hole formed on the outer surface of the
cylinder, wherein the detectable sensor is received in the second transverse
hole.
2. A chain hoist as claimed in claim 1, wherein the sensor detection
member communicates directly the actuator arrangement for stopping the
chain hoist when the limiter member and the detectable sensor are at the
predetermined distance from the sensor detection member.
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5
3. A chain hoist as claimed in claim 1 or 2, wherein the sensor detection
member is placed inside the body, at the immediate vicinity of a through-hole.
4. A chain hoist as claimed in any one of claims 1 to 3, wherein the
detectable sensor is a magnet and the sensor detection member is a magnet
detector.
5. A chain hoist, comprising:
a body;
a passage extending through the body;
a hoist chain passing through the passage;
an actuator within the body, the actuator providing relative movement
between the body and hoist chain; and
a limiter member, in a form of a cylinder, attached to the hoist chain, the
limiter member being provided with a detectable sensor,
wherein the body has a sensor detection member to detect the
detectable sensor at a predetermined distance from the sensor detection
member, and
wherein the limiter member comprises:
an axial through-hole for the hoist chain;
a first transverse hole running through the cylinder and
intersecting the axial through-hole;
a pair of locking pins placed into the first transverse hole and
pressing against the hoist chain on both sides thereof to releasable fix the
limiter member to the hoist chain;
a peripheral groove extending around the entire periphery of an
outer surface of the cylinder, overlapping with the first transverse hole;
a resilient locking ring placed into the peripheral groove, running
over the pair of locking pins and pressing the pair of locking pins in place
in a
resilient manner; and
a second transverse hole formed on the outer surface of the
cylinder, wherein the detectable sensor is received in the second transverse
hole.
Date Recue/Date Received 2021-01-04

6
6. A chain hoist, comprising:
a body;
a hoist chain passing through the body;
a first through-hole in the body for the hoist chain;
a second through-hole in the body for the hoist chain;
an actuator arrangement for operating the chain hoist, the actuator
being used for moving the hoist chain through the first and second through-
holes in a lifting or lowering direction of the chain hoist;
a limiter member attached to the hoist chain, the limiter member being
provided with a detectable sensor; and
the body having a sensor detection member to detect the detectable
sensor at a predetermined distance from the sensor detection member,
wherein the limiter member is a cylinder comprising:
an axial through-hole for the hoist chain;
a first transverse hole running through the cylinder and
intersecting the axial through-hole;
a pair of locking pins placed into the first transverse hole and
pressing against the hoist chain on both sides thereof to releasable fix the
limiter member to the hoist chain;
a peripheral groove extending around the entire periphery of an
outer surface of the cylinder, overlapping with the first transverse hole;
a resilient locking ring placed into the peripheral groove, running
over the pair of locking pins and pressing the air of locking pins in place in
a
resilient manner; and
a second transverse hole formed on the outer surface of the
cylinder, wherein the detectable sensor is received in the second transverse
hole.
7. The chain hoist as claimed in claim 5 or 6, wherein the sensor detection
member communicates directly with the actuator arrangement for stopping the
chain hoist when the limiter member and the detectable sensor provided
therein are at the predetermined distance from the sensor detection member.
8. The chain hoist as claimed in any one of claims 5 to 7, wherein the
sensor detection member is placed inside the body.
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7
9. The chain hoist as claimed in any one of claims 5 to 8, wherein the
detectable sensor is a magnet and the sensor detection member is a magnet
detector.
Date Recue/Date Received 2021-01-04

Description

CA 02863120 2014-09-09
1
Chain hoist
Background of the invention
[0001] The invention relates to a chain hoist comprising a body; a
hoist chain passing through the body; a first through-hole in the body for the
hoist chain; a second through-hole in the body for the hoist chain; an
actuator
arrangement for operating the chain hoist, the actuator being used for moving
the hoist chain through said through-holes in a lifting or lowering direction
of
the chain hoist.
[0002] A chain hoist of the invention is used particularly in theatre
applications or the like in which an object to be lifted, such as a scenic
object,
must be lifted or lowered rapidly and precisely to the correct height.
[0003] In prior art solutions the correct height must be estimated by
the eye and the hoist must be stopped on the basis of this, usually
inaccurate,
estimate which means that corrective moves have to be made. In connection
with this, accidents may happen due to the object to be lifted hitting
something
and thus damaging both the object and the environment. In the worst case
scenario personal injury may occur.
Summary of the invention
[0004] An object of the invention is to provide a novel chain hoist so
as to enable the above-described problems to be solved. This is achieved by a
chain hoist of the invention, characterized in that on the side of at least
one
through-hole the portion of the hoist chain moving outside the body is
provided
with a limiter member whose position in the longitudinal direction of the
hoist
chain is adjustable, the limiter member being provided with a detectable sen-
sor; and a sensor detection member is provided in the vicinity of said through-
hole to detect the detectable sensor at a predetermined distance.
[0005] The sensor detection member most preferably communi-
cates directly with the actuator arrangement for stopping the chain hoist when
the limiter member and the sensor provided therein are at said detection dis-
tance from the sensor detection member.
[0006] Other preferred embodiments of the invention are disclosed
in the dependent claims.
[0007] With the chain hoist of the invention all hoists can be made
precisely to the right position after the lifting heights have been determined
by
the limiter member that is preferably slidable on the hoist chain and lockable
to

2
a desired position, the sensor in the limiter member and the sensor in the
body
then co-operating to provide a stop command to the chain hoist actuator. The
invention provides such precision that the limiter member may be stopped at a
distance of one chain loop from the hoist body. This allows an automated
lifting
height to be determined with extreme precision.
[0007a] In one aspect, there is provided a chain hoist, comprising:
a body; a hoist chain passing through the body; a first through-hole in the
body
for the hoist chain; a second through-hole in the body for the hoist chain; an
actuator arrangement for operating the chain hoist, the actuator being used
for
moving the hoist chain through said through-holes in a lifting or lowering
direc-
tion of the chain hoist, on the side of at least one through-hole the portion
of
the hoist chain moving outside the body is provided with a limiter member
whose position in the longitudinal direction of the hoist chain is adjustable,
the
limiter member being provided with a detectable sensor; and a sensor detec-
tion member is provided in the vicinity of said through-hole to detect the de-
tectable sensor at a predetermined distance, wherein the limiter member has
locking members that press resiliently against the hoist chain, the locking
members being locking pins, and wherein the limiter member is a cylinder with:
an axial through-hole for the hoist chain; a first transverse hole running
through
the cylinder and intersecting the through-hole; the locking pins being placed
in-
to the transverse hole and pressing against the hoist chain on both sides
thereof; a peripheral groove running on the outer surface of the cylinder at
the
transverse hole; a resilient locking ring placed into the peripheral groove to
keep the locking pins in place in a resilient manner; and a second transverse
hole formed on the outer surface of the cylinder, wherein the detectable
sensor
is received in the second transverse hole.
[0007b] In another aspect, there is provided a chain hoist, compris-
ing: a body; a passage extending through the body; a hoist chain passing
through the passage; an actuator within the body, the actuator providing rela-
tive movement between the body and hoist chain; and a limiter member, in a
form of a cylinder, attached to the hoist chain, the limiter member being pro-
vided with a detectable sensor, wherein the body has a sensor detection
member to detect the detectable sensor at a predetermined distance from the
sensor detection member, and wherein the limiter member comprises: an axial
through-hole for the hoist chain; a first transverse hole running through the
cyl-
inder and intersecting the axial through-hole; a pair of locking pins placed
into
Date Recue/Date Received 2021-01-04

2a
the first transverse hole and pressing against the hoist chain on both sides
thereof to releasable fix the limiter member to the hoist chain; a peripheral
groove extending around the entire periphery of an outer surface of the cylin-
der, overlapping with the first transverse hole; a resilient locking ring
placed in-
to the peripheral groove, running over the pair of locking pins and pressing
the
pair of locking pins in place in a resilient manner; and a second transverse
hole
formed on the outer surface of the cylinder, wherein the detectable sensor is
received in the second transverse hole.
[0007c] In still another aspect, there is provided a chain hoist, com-
prising: a body; a hoist chain passing through the body; a first through-hole
in
the body for the hoist chain; a second through-hole in the body for the hoist
chain; an actuator arrangement for operating the chain hoist, the actuator be-
ing used for moving the hoist chain through the first and second through-holes
in a lifting or lowering direction of the chain hoist; a limiter member
attached to
the hoist chain, the limiter member being provided with a detectable sensor;
and the body having a sensor detection member to detect the detectable sen-
sor at a predetermined distance from the sensor detection member, wherein
the limiter member is a cylinder comprising: an axial through-hole for the
hoist
chain; a first transverse hole running through the cylinder and intersecting
the
axial through-hole; a pair of locking pins placed into the first transverse
hole
and pressing against the hoist chain on both sides thereof to releasable fix
the
limiter member to the hoist chain; a peripheral groove extending around the
entire periphery of an outer surface of the cylinder, overlapping with the
first
transverse hole; a resilient locking ring placed into the peripheral groove,
run-
ning over the pair of locking pins and pressing the air of locking pins in
place in
a resilient manner; and a second transverse hole formed on the outer surface
of the cylinder, wherein the detectable sensor is received in the second trans-
verse hole.
[0008] The solution of the invention is simple by design and afford-
able to implement, and it is also suitable for retrofitting existing chain
hoists. In
addition to the uses mentioned at the beginning, also industrial applications
of
the chain hoist are possible.
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2b
List of figures
[0009] The invention is now described in closer detail by means of
one preferred embodiment and with reference to the accompanying drawings,
in which
Figure 1 is a cross-sectional view of a chain hoist of the invention;
and
Figure 2 is an explosion view of a limiter member visible in Figure 1.
Detailed description of the invention
[0010] With reference to Figure 1, a chain hoist of the invention
comprises a body 1; a hoist chain 2 passing through the body 1; a first,
upper,
through-hole 3 in the body 1 for the hoist chain 2; a second, lower, through-
hole 4 in the body 1 for the hoist chain 2, and an actuator arrangement 5, 6,
7
(an electric motor 5, a gear 6 and a chain wheel 7) for operating the chain
hoist, the arrangement being used for moving the hoist chain 2 through the
through-holes 3 and 4 in a lifting or lowering direction of the chain hoist.
In this
application the through-hole 3 is on an upper surface of the body 1 and the
through-hole 4 on a side surface of the body 1. In this application a lifting
hook
8 needed in the lifting is attached to an underside of the body I. The top end
of
the hoist chain 2 is fastened to a support structure (not shown) provided up
in
the lifting space by e.g. a second lifting hook (not shown) fastened to the
top
end of the hoist chain 2. During lifting, the body 1 and the lifting hook 8
move
along the hoist chain 2, excess hoist chain 2 being collected into and
released
from a chain bag 9 arranged below the through-hole 4. Of course, the chain
hoist may also be used in a "reverse mode", i.e. by fastening it to said
support
structure of the lifting space by the lifting hook 8, the body 1 of the chain
hoist
being thus stationary and the hoist chain 2 being "reeled" into or out of the
Date Recue/Date Received 2021-01-04

CA 02863120 2014-09-09
3
body 1 with the chain bag 9 being used also in this case for collecting excess
hoist chain 2.
[0011] An essential aspect of the chain hoist of the invention is that
on the side of at least one through-hole 3, 4 the portion of the hoist chain 2
moving outside the body 1 is provided with a limiter member 10 whose position
in the longitudinal direction of the hoist chain 2 is adjustable, the limiter
mem-
ber being provided with a detectable sensor 11; and that a sensor detection
member 12 is provided in the vicinity of the through-hole 3, 4 to detect the
de-
tectable sensor 11 at a predetermined distance. In this example the limiter
member 10 and the detectable sensor 11 are arranged on each part of the
hoist chain 2 moving outside the through-holes 3, 4 and the sensor detection
member 12 is arranged inside the body 1 at the immediate vicinity of the
through-holes 3, 4.
[0012] The detectable sensor 11 may be e.g. a magnet and the
sensor detection member 12 may be a magnet detector. Also other commonly
known detection pairs recognizing one another are possible.
[0013] The sensor detection member 12 is configured to communi-
cate directly with the actuator arrangement 6, 7, 8 for stopping the chain
hoist
when the limiter member 10 and the sensor 11 provided therein are at said de-
tection distance from the sensor detection member 12. This detection distance
may be as short as the distance corresponding to a length of one chain loop.
[0014] For the limiter member 10 to be easily slidable on the hoist
chain 2 and lockable to a desired point there, the limiter member 10 is
provided
with locking members that press against the hoist chain 2 in a resilient
manner.
[0015] The limiter member 10 is preferably a cylinder with an axial
through-hole 13 for the hoist chain 2, a transverse hole 14 running through
the
cylinder 10 and intersecting the through-hole 13, locking pins 15 placed in
the
transverse hole 14 and pressing against the hoist chain 2 on both sides there-
of; a peripheral groove 16 running on the outer surface of the cylinder 10 at
the
transverse hole 14; a resilient locking ring 17 placed into the peripheral
groove
16 to keep the locking pins 15 in place in a resilient manner; and a space 18
(drilling) for the sensor 11. In addition, around this assembly there is a
resilient
rubber cover 19 which also ensures that the above components stay in place.
[0016] The above description of the invention is only intended to il-
lustrate the basic idea of the invention. A person skilled in the art may thus
vary its details within the scope of the attached claims.

Representative Drawing