Title of Invention	"AN ANTIBLOCK SYSTEM FOR USE WITH A CRANE"
Abstract	This invention relates to an antiblock system for use with a crane to prevent dangling of the snatch block while the crane is in movement over a surface comprising:- (i) snatch block assembly having an auxiliary block with a seat; (ii) an engaging member attached to a front plate, said engaging member is disposed within said seat when the snatch block is actuated towards said front plate; (iii) a shock absorbing member provided with said front plate; (iv) a rear plate disposed in a spaced relationship to said front plate; (v) a limit switch attached to said rear plate and disposed in the proximity of said front plate and is in an actuated condition when said front plate strikes the front end of the limit switch.

Title of Invention

"AN ANTIBLOCK SYSTEM FOR USE WITH A CRANE"

Abstract

This invention relates to an antiblock system for use with a crane to prevent dangling of the snatch block while the crane is in movement over a surface comprising:- (i) snatch block assembly having an auxiliary block with a seat; (ii) an engaging member attached to a front plate, said engaging member is disposed within said seat when the snatch block is actuated towards said front plate; (iii) a shock absorbing member provided with said front plate; (iv) a rear plate disposed in a spaced relationship to said front plate; (v) a limit switch attached to said rear plate and disposed in the proximity of said front plate and is in an actuated condition when said front plate strikes the front end of the limit switch.

Full Text	FIELD OF INVENTION This invention relates to an antiblock system for use with a crane. In particular, this invention relates to an antiblock system which prevents a dangling of the snatch block while the crane is in movement over a surface. BACKGROUND OF THE INVENTION A disadvantage assoicated with the known construction of cranes is that while the crane is in movement on the road or in the field, the snatch block dangles or swings randomly. Such a dangling movement can damage the snatch block and the winch rope. OBJECT OF. THE INVENTION An object of this invention is to propose an antiblock system for use with a crane and which obviates the aforesaid disadvantage. Another object of this invention is to propose an antiblock system for use with a crane which does not allow dangling of the snatch block while the crane is in movement over a surface. Still another object of this invention is to propose an antiblock system for use with a crane which works as an over-hoist protection system. Yet another object of this invention is to propose an antiblock system for use with a crane which provides more working clearance to the operator. A further object of this invention is to propose an antiblock system for use with a crane and wherein the wire rope remains in tension. DESCRIPTION OF. THE INVENTION According to this invention there is provided an antiblock system for use with a crane to prevent a dangling of the snatch block while the crane is in movement over a surface comprising: i) said snatch block assembly having an auxilliary block with a seat, ii) an engaging member held to a front plate, said engaging member adapted to be disposed within said seat when the snatch block is actuated towards said front plate, iii) a shock absorbing member provided with said front plate. iv> a rear plate disposed in a spaced relationship to said front plate, v) a limit switch held to said rear plate and disposed in the proximity of said front plate and being in an actuated condition when said front plate strikes or bears against the front end of the limit switch. In accordance with this invention an auxialliary block is welded or held to the snatch block, said auxilliary block having a seat. The device further comprises an engaging member held to a front plate, said engaging member adapted to be disposed within said seat. A coiled spring embraces a spindle, one end of said spring adapted to rest on the front plate, the opposite end adapted to bear against a rear plate. The spindle extends through the rear plate and has engaging threads for receiving a nut. The nut bears against the rear plate and such that by rotating the spindle the force exerted by the shock absorbing member on the front plate can be adjusted. The front plate is a movable plate, a limit switch is provided with the rear plate, the front end of said limit switch adapted to be disposed in the proximity but in a spaced relationship to said front plate. The limit switch is connected to the winch motor or to any suitable signal means, said limit switch being in an actuated condition when the front plate strikes the front end of said switch. DESCRIPTION OF THE INVENTION WITH REFERENCE TO ACCOMPANYING DRAWINGS Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings and wherein: Referring to Fig. 1, the anti block system is held to a boom 11 of a crane through a pivot plate 12. Such features of a crane having a boom 11 and a pivot plate 12 are known in the art and do not form a concept of the present invention. Specifically, the present invention resides in an antiblock system mounted on a bush 10 between two pulleys 13 on the pivot plate 12 of boom 11. An auxiliary block 4 is welded on an upper plate 3 of the snatch block assembly 14. Block 4 has a seat 4a. The device further comprises a front plate 6 held to the lower end of a spindle 15. A frusto conical engaging member comprising a pin 2 and a stud 3 is held to spindle 15 and bears against plate 6. It is generally known that while travelling without load, an operator needs to wind the rope up with the help of a winch motor. A disadvantage associated with the prior art is that even while raising the snatch block, it is retained in a dangling condition. Such a disadvantage is obviated by the present invention. Thus, while raising the snatch block 14, block 4 with seat 4a gets engaged with pin 2 first and then member 3. As seat 4a has a matching profile to that of pin 2 and member 3 a dangling movement of snatch block assembly 14 is prevented. Reference is made to a frusto conical member. However the member can be of any other shape with seat 4 a having a mating profile. When the operator continues to wind the winch rope, block 4 pushes plate 6 upwards and against a force applied by coiled spring 7. One end of spring 7 rests on front plate 7, the opposite end is adapted to bear against a rear plate 5. Spindle 15 extends through rear plate 5 and has threads mating with threads of nut 1. Nut 1 bears against plate 5. A limit switch- 8 is held to plate 5, the front end of limit switch 8 terminating away but in the proximity of front plate 6. Upon a contact being established between plate 6 and limit switch 8 consequential to the further upward displacement of front plate 6, limit switch 8 is activated. Limit switch is connected to an audio alarm (not shown) so that an operator receives an alarm that the snatch block is in a. locked condition, and to thereby stop the further winding of the wire rope. Pin 2 and member 3 being engaged with in seat 4a ensures a prevention of a dangling of the snatch block. The distance of the center of hook 16 from the pulley center is reduced to 860 mm from 1360 mm of the known art, and thereby provides an additional 0.5m clearance below snatch block 14, in turn the lift height is gained by 0.5m. Hence the workable clearance also increases. The wire rope remains in tension which ensures that the wire rope doesn't foul with anything and it also doesn't get entangled. CLAIM 1. An antiblock system for use with a crane to prevent a dangling of the snatch block while the crane is in movement over a surface comprising: i) said snatch block assembly having an auxilliary block with a seat, ii an engaging member held to a front plate, said engaging member adapted to be disposed within said seat when the snatch block is actuated towards said front plate, iii) a shock absorbing member provided with said front plate. iv) a rear plate disposed in a spaced relationship to said front plate, v a limit switch held to said rear plate and disposed in the proximity of said front plate and being in an actuated condition when said front plate strikes or bears against the front end of the limit switch. 2. An antiblock device as claimed in claim 1 wherein said shock absorbing member comprises a coiled spring embracing a pin, one end of said spring adapted to rest on the front plate, the opposite end adapted to bear against a rear plate. 3. An antiblock device as claimed in claim 1 wherein said spindle extends through the rear plate and has engaging threads for receiving a nut. 4. An antiblock device as claimed in claim 3 wherein the nut bears against the rear plate and such that by rotating the spindle the force exerted by the shock absorbing member on the front plate can be adjusted. 5. An antiblock device as claimed in claim 1 wherein said front plate is a movable plate. 6. An antiblock device for use with a crane substantially as herein described and illustrated.

Full Text

FIELD OF INVENTION
This invention relates to an antiblock system for use with a crane. In particular, this invention relates to an antiblock system which prevents a dangling of the snatch block while the crane is in movement over a surface.
BACKGROUND OF THE INVENTION
A disadvantage assoicated with the known construction of cranes is that while the crane is in movement on the road or in the field, the snatch block dangles or swings randomly. Such a dangling movement can damage the snatch block and the winch rope.
OBJECT OF. THE INVENTION
An object of this invention is to propose an antiblock system for use with a crane and which obviates the aforesaid disadvantage.
Another object of this invention is to propose an antiblock system for use with a crane which does not allow dangling of the snatch block while the crane is in movement over a surface.
Still another object of this invention is to propose an antiblock system for use with a crane which works as an over-hoist protection system.
Yet another object of this invention is to propose an antiblock system for use with a crane which provides more working clearance to the operator.
A further object of this invention is to propose an antiblock system for use with a crane and wherein the wire rope remains in tension.
DESCRIPTION OF. THE INVENTION
According to this invention there is provided an antiblock system for use with a crane to
prevent a dangling of the snatch block while
the crane is in movement over a surface comprising:
i) said snatch block assembly having an
auxilliary block with a seat,
ii) an engaging member held to a front plate,
said engaging member adapted to be disposed within
said seat when the snatch block is actuated
towards said front plate,
iii) a shock absorbing member provided with
said front plate.
iv> a rear plate disposed in a spaced
relationship to said front plate,
v) a limit switch held to said rear plate and disposed in the proximity of said front plate and being in an actuated condition when said front plate strikes or bears against the front end of the limit switch.
In accordance with this invention an auxialliary block is welded or held to the
snatch block, said auxilliary block having a seat.
The device further comprises an engaging member held to a front plate, said engaging member adapted to be disposed within said seat.
A coiled spring embraces a spindle, one end
of said spring adapted to rest on the front
plate, the opposite end adapted to bear against a
rear plate.
The spindle extends through the rear plate and has engaging threads for receiving a nut. The nut bears against the rear plate and such that by rotating the spindle the force exerted by the shock absorbing member on the front plate can be adjusted.
The front plate is a movable plate, a limit switch is provided with the rear plate, the front end of said limit switch adapted to be disposed in the proximity but in a spaced
relationship to said front plate. The limit
switch is connected to the winch motor or to
any suitable signal means, said limit switch being
in an actuated condition when the front plate
strikes the front end of said switch.
DESCRIPTION OF THE INVENTION WITH REFERENCE TO ACCOMPANYING DRAWINGS
Further objects and advantages of this
invention will be more apparent from the
ensuing description when read in conjunction with
the accompanying drawings and wherein:
Referring to Fig. 1, the anti block system is held to a boom 11 of a crane through a pivot plate 12. Such features of a crane having a boom 11 and a pivot plate 12 are known in
the art and do not form a concept of the present invention.
Specifically, the present invention resides in an antiblock system mounted on a bush 10 between two pulleys 13 on the pivot plate 12 of boom 11. An auxiliary block 4 is welded on an upper plate 3 of the snatch block assembly 14. Block 4 has a seat 4a. The device further comprises a front plate 6 held to the lower end of a spindle 15. A frusto conical engaging member comprising a pin 2 and a stud 3 is held to spindle 15 and bears against plate 6.
It is generally known that while travelling without load, an operator needs to wind the rope up with the help of a winch motor. A disadvantage associated with the prior art is that even while raising the snatch block, it is retained in a dangling condition. Such a disadvantage is obviated by the present invention. Thus, while
raising the snatch block 14, block 4 with seat 4a gets engaged with pin 2 first and then member 3. As seat 4a has a matching profile to that of pin 2 and member 3 a dangling movement of snatch block assembly 14 is prevented. Reference is made to a frusto conical member. However the member can be of any other shape with seat 4 a having a mating profile.
When the operator continues to wind the winch rope, block 4 pushes plate 6 upwards and against a force applied by coiled spring 7. One end of spring 7 rests on front plate 7, the opposite end is adapted to bear against a rear plate 5. Spindle 15 extends through rear plate 5 and has threads mating with threads of nut 1. Nut 1 bears against plate 5. A limit switch- 8 is held to plate 5, the front end of limit switch 8 terminating away but in the proximity of front plate 6.
Upon a contact being established between plate 6 and limit switch 8 consequential to the further upward displacement of front plate 6, limit switch 8 is activated. Limit switch is connected to an audio alarm (not shown) so that an operator receives an alarm that the snatch block is in a. locked condition, and to thereby stop the further winding of the wire rope. Pin 2 and member 3 being engaged with in seat 4a ensures a prevention of a dangling of the snatch block.
The distance of the center of hook 16 from the pulley center is reduced to 860 mm from 1360 mm of the known art, and thereby provides an additional 0.5m clearance below snatch block 14, in turn the lift height is gained by 0.5m. Hence the workable clearance also increases. The wire rope remains in tension which ensures that the wire rope doesn't foul with anything and it also doesn't get entangled.

CLAIM
1. An antiblock system for use with a crane to prevent a dangling of the snatch block while the crane is in movement over a surface comprising:
i) said snatch block assembly having an
auxilliary block with a seat,
ii an engaging member held to a front plate,
said engaging member adapted to be disposed within
said seat when the snatch block is actuated
towards said front plate,
iii) a shock absorbing member provided with
said front plate.
iv) a rear plate disposed in a spaced
relationship to said front plate,
v a limit switch held to said rear plate and
disposed in the proximity of said front plate and
being in an actuated condition when said front
plate strikes or bears against the front end
of the limit switch.
2. An antiblock device as claimed in claim 1
wherein said shock absorbing member comprises a
coiled spring embracing a pin, one end of said
spring adapted to rest on the front plate, the
opposite end adapted to bear against a rear
plate.
3. An antiblock device as claimed in claim 1
wherein said spindle extends through the
rear plate and has engaging threads for
receiving a nut.
4. An antiblock device as claimed in claim 3
wherein the nut bears against the rear plate
and such that by rotating the spindle the
force exerted by the shock absorbing member on the
front plate can be adjusted.
5. An antiblock device as claimed in claim 1
wherein said front plate is a movable plate.
6. An antiblock device for use with a crane
substantially as herein described and illustrated.

Documents:

1579-del-1998-abstract.pdf

1579-del-1998-claims.pdf

1579-del-1998-correspondence-others.pdf

1579-del-1998-correspondence-po.pdf

1579-del-1998-description (complete).pdf

1579-del-1998-drawings.pdf

1579-del-1998-form-1.pdf

1579-del-1998-form-19.pdf

1579-del-1998-form-2.pdf

1579-del-1998-form-3.pdf

1579-del-1998-gpa.pdf

1579-del-1998-pa.pdf

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Patent Number

220319

Indian Patent Application Number

1579/DEL/1998

PG Journal Number

30/2008

Publication Date

25-Jul-2008

Grant Date

22-May-2008

Date of Filing

09-Jun-1998

Name of Patentee

ESCORTS CONSTRUCTION EQUIPMENT LIMITED

Applicant Address

Inventors:

#	Inventor's Name	Inventor's Address
1	R.S. JOON

PCT International Classification Number

B60T 8/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA