DE202009014059U1 - telescopic pliers - Google Patents

Abstract

Telescopic forceps (1) with
- A pliers housing (2); such as
- a first (3) and a second (4) pliers leg;
- wherein each pliers limb (3; 4) comprises a guide support (3a; 4a) and a support arm (3b; 4b) arranged thereon; and
Wherein at least one pliers limb (3; 4) is held in the pliers housing (2) by means of its guide support (3a; 4a) in such a way that it can be moved by drive means (10, 20 or 10, 30),
by the drive means
- One of an electric motor (10) driven chain (20) or
At least one trapezoidal threaded spindle (30) driven by the electric motor (10)
include, with which the / the limbs (3, 4) are operatively connected via driving means;
characterized in that
between a movable pliers leg (3; 4) and the drive means (chain 20 or trapezoidal threaded spindle 30) is at least two entrainment means (5; 21, 25 and 31, 35) comprehensive shutdown device (40) for the electric motor (10) is arranged, one of which ...

Description

The The present invention relates to a telescopic pliers for transporting heavy loads such as coils, laminations, slabs, rolls, paper rolls or the like; with a tong housing; and a first and a second pliers leg; with each pliers leg one Guide carrier and a support arm arranged thereon includes; and at least one pliers leg by means of its guide carrier is held in such a way that this over Drive means is movable by the drive means one of an electric motor driven chain or at least one of the electric motor driven trapezoidal threaded spindle, with which the / over the thighs Carrier are in operative connection.

For the safe transport and safe handling of customer-specific loads of different dimensions and weights are preferably so-called telescopic pliers, such as generic form, for example, from the US 4,261,609 A or the EP 0 802 146 A1 are known. Telescoping pliers commonly have a pliers housing and two pliers legs, wherein the legs comprise a guide support and a support arm arranged thereon, on which, for example, a claw or the like lifting means can be arranged, which usually take the load on the side, so undercut. At least one pliers leg is held in the pliers housing by means of its guide carrier in such a way that it can be moved by means of drive means. In this context one speaks also of the telescoping of the pliers leg, from which the name of the pliers derived. Often both pliers legs are telescopically supported in the pliers housing, which advantageously a modular pliers construction is possible. The modular construction means that the number of variants is reduced, which is in the sense of the always desired identical part concept.

For the automated movability of the pliers legs in the pliers housing The use of electro-mechanical chain drives is widespread. The preferably of an electric motor for adjusting the leg provided forces are interposed of friction clutches on the drive sprocket of the chain drive passed, which is in operative connection with the legs.

The Slip clutch as a component of the mechanics is located at the Drive shaft of the engine. Upon reaching a defined torque disconnects or connects the clutch without external (foreign) influence. In principle, slip clutches are therefore used where due to the system separation by the coupling especially the overload of machine elements avoided should be.

The contact pressure of such slip clutches is usually adjustable or variable. However, a problem is that the load during transport through the crane system z. B. Inattention of the crane operator or in poorly visible spaces on - in 1 and 2 exemplified - sturgeon contours meet and opening the pliers legs 3 respectively. 4 can not prevent under load. In 1 shown is a start of loads 100 with horizontal axis position 101 to fixed objects such as masonry 102 Etc.; in 2 shown is a tilting of the pliers 1 by one-sided placement of the load 100 on an adjacent load 100 , whereby thereby load 100 and pliers 1 get out of the vertical position and the load 100 can slip. The same problem can occur when the load 100 For example, on a very uneven terrain or on a very uneven surface is discontinued. Thereby and through that at the same time by the in 1 and 2 shown situations of forces on the forceps legs 3 and or 4 the telescopic pliers 1 as well as the electro-mechanical chain drive can open the pliers unintentionally due to the execution of a telescopic pliers with slip clutches.

However, slipping or falling heavy loads from the tongs can cause considerable damage. To avoid this is from the DE 102 25 596 A1 already known to block the chain drive after reaching desired gripping widths by means of a blocking device.

Alternatively, in the DE 103 42 063 A1 proposed to provide between each movable pliers leg and the pliers housing a pliers leg substantially steetierendes locking means such esp. A preferably unpowered, cooperating with a check valve, hydraulic cylinder.

Furthermore is known as a self-locking drive, by an electric motor driven trapezoidal threaded spindles for movability to provide the pliers legs. These are, however, in particular due to their complex storage relatively expensive. In addition, the adjustment speed is limited. Also the life of this drive, in particular the spindle nut, is lower. Finally, even with a trapezoidal thread spindle drive the forces provided by the electric motor to adjustment the leg with the interposition of slip clutches in the Spindle drive passed.

To protect the slip clutches is known this via electromechanical or electronic switch (sensor-controlled) must be combined with a control which stops the drive when the drive is at standstill or falls below the setpoint speed on the output side (clutch slips). Such switches, which are also referred to as standstill or speed monitor, but are shock sensitive. So it could be observed in the past again and again that due to failed sensor-controlled switch slipping clutches unnoticed and engines remained undecided, although probably the current situation would have required. As long as the crane operator has not reached the desired gripping position or due z. B. of interference contours (see. 1 and 2 ) as a precaution, it will remain more than necessary on the button for activating the electric motor. Not designed for continuous operation slipping clutches wear but not only fast but already after a few cumulative minutes of slipping unusable and replace considerable effort.

From the DE 36 32 192 C2 a gripper drive unit is known, which is designed as electromechanical linear drive unit with concentric implementation of rotary motion in linear motion of a drive rod such that the linear drive unit has two counter-rotating, driven by an electric motor, output rods on opposite sides and that the linear drive unit, as a supporting component of Gripper provided, each provided with an over its housing output shaft is provided on each drive rod, wherein the gripper drive unit is provided with a position-dependent Endabschaltung and / or a force-dependent shutdown, so that the shutdown of the driving electric motor of the gripper drive unit, if either the inner or outer end position of the two output sleeves is reached or when in Auseinanderbewegungsrichtung or Zusammenbewegungsrichtung the output hulls a certain closing force, which in the Zu sammendrücken a disc spring package expresses or given by the spring rate of the disc springs is exceeded.

Finally, be on the DE W 0011406 AZ and the DD 129 317 A1 pointed.

task the invention is an improved, in particular more reliable, Shutdown device for the electric motor of a drive unit To provide a telescopic forceps, which esp. Easier in construction and sensitive switching avoids the aforementioned disadvantages.

These The object is solved by the features of the protection claim 1. Advantageous embodiments of the invention, which individually or in combination with each other, give the dependent Claims to.

The Invention builds on generic telescopic forceps characterized in that a shutdown device for the electric motor between each movable pliers leg and the drive means (Chain or trapezoidal threaded spindle) is arranged. The shutdown device comprises at least two driving means, one of which chain or trapezoidal threaded spindle arranged average driving means opposite the / the other arranged on the leg entrainment means / n means Spring force defines movable (or "floating") is stored or vice versa. The defined mobile or "floating" storage a part of the shutdown allows the detection of Force peaks in the clamp operation. These commonly occur when the Leg end positions, ie their open or closed positions, reach, or come to a load to lie down. Are the detected Passing force peaks to shut-off means of the shut-off device, is the reliable shutdown of the drive for protection the load or other damage. The inventive arrangement of a turn-off for the / the electric motors of the drive unit can be advantageous be dispensed with the use of slip clutches. With the renunciation On slip clutches account advantageously also susceptible to failure Standstill or speed monitor or comparable sensor-controlled Switches such as so-called. Overcurrent relay. Across from Switch versions of telescopic pliers with friction clutches Telescopic pliers arranged according to the invention Depositing devices noticeably more sensitive, which advantageous their Operational safety increased.

According to the invention preferred is defeat by the between the dogs on the pliers legs and a chain connector or a trapezoidal nut arranged formed mean driving means, compared to the chain connector or the trapezoidal nut and / the entrainment / s on the leg Defined movable by spring force is arranged.

Conveniently, is a shutdown device arranged according to the invention both in the positive and in the negative direction of travel of the pliers legs designed switchable. This can be advantageous in particular hitherto possibly for the detection of end and / or Save intermediate positions of the gripping arms provided shutdown.

In a further embodiment of the shutdown device includes these preferably therefore one in positive and one in negative displacement direction addressable end or position switch.

After all the shutdown device includes a preferred in positive and a switching flag acting in a negative displacement direction, by means of which the end or position switches can be activated.

With the inventive arrangement of a shutdown device between each movable pliers leg and the drive means is an improved, especially needs-based turn-off, Telescopic pliers provided which are known in the art Disadvantages avoids. In particular, by dispensing with a slip clutch ultimately provided a self-locking chain drive in which the drive means the pliers legs even in the event that load and Pliers come out of the vertical position or against an obstacle push together, hold together. Beyond that the drive means switched off as needed, as soon as the process the leg detects the shutdown force peaks. A such needs-appropriate shutdown of the drive means avoids finally when using trapezoidal threaded spindles advantageous otherwise given deadlock danger.

The Invention will now be described with reference to the accompanying drawings preferred embodiments for telescopic coil tongs, to which the invention is not limited, exemplified.

It show schematically:

1 the risk of accident of a non-self-locking telescopic coil tongs when starting the load to a stationary object;

2 the risk of accident of a non-self-locking telescopic coil tongs when tilting the pliers by one-sided placement of the load;

3 a typical telescopic coil tongs in a front view;

4 the telescopic coil tongs after 3 in a plan view;

5 a section of a telescopic pliers with chain drive in a plan view with an exemplary shutdown device according to the invention;

6 the shutdown device in the enlarged section "A" to 5 ;

7 the telescopic pliers with chain drive behind 5 in a perspective view;

8th the shutdown device in the enlarged section "B" after 7 ;

9 a detail of a telescopic pliers with trapezoidal spindle drive in a plan view with an exemplary shutdown device according to the invention;

10 the shutdown device in the enlarged section "A" to 9 ;

11 the telescopic pliers with chain drive behind 9 in a perspective view; and

12 the shutdown device in the enlarged section "B" after 11 ,

at the following description of the preferred embodiments In the present invention, like reference characters designate like or comparable components.

1 shows the accident risk of a non-self-locking telescopic coil tongs 1 when starting a coil 100 to a fixed masonry 102 ; 2 the risk of accident of a non-self-locking telescopic coil tongs 1 when tilting the pliers 1 by one-sided placement of the coil 100 , Both figures have already been explained in the introduction to the description.

3 shows in a front view, 4 in the corresponding plan view, a typical telescopic coil tongs 1 with a clamp housing 2 and a first 3 and a second one 4 Pliers legs. Each pliers leg 3 ; 4 includes a leadership carrier 3a ; 4a and a support arm arranged thereon 3b ; 4b , in which esp. a claw 3c . 4c for holding coils 100 is arranged. Both pliers legs are preferred by means of their guide carrier 3a ; 4a in the clamp housing 2 held in such a way that these via drive means 10 and 20 respectively. 30 are movable.

In 3 to 8th is as a drive for each pliers leg 3 ; 4 a chain drive with a chain 20 provided, which over with a pinion 24 operatively connected chain tensioner 22 is tensionable and the via a drive sprocket 23 from an electric motor 10 is driven. The chain 20 further acts with each of the pliers legs 3 ; 4 associated driving means (driver 5 on the pliers leg 3 . 4 ; chain connector 21 ; middle driver 25 on the chain connector 21 ) in such a way that a mobility of the pliers legs 3 ; 4 is effected.

In 9 to 12 is as a drive for each pliers leg 3 ; 4 at least one (not shown) or a trapezoidal threaded spindle 30 provided, which also of at least one electric motor 10 are driven. The trapezoidal thread spindle 30 also acts with each of the pliers thighs 3 ; 4 associated driving means (driver 5 on the pliers leg 3 . 4 ; Trapezoidal threaded nut 31 ;, middle driver 35 on the spindle nut 31 ) in such a way that a mobility of the pliers legs 3 and or 4 is effected.

The drive means can thus one of an electric motor 10 driven chain 20 or at least one trapezoidal threaded spindle 30 include, with which / the legs 3 . 4 via take-along means 5 ; 21 . 25 respectively. 31 . 35 are in operative connection, wherein in a first embodiment of the shutdown device 40 from the takeaway 25 ; 35 on chain 20 or trapezoidal threaded spindle 30 and the means of transport / s 5 on the thigh 3 ; 4 the one driving device 25 ; 35 towards the other means of transport / s 5 Defined movably mounted by spring force is arranged or vice versa.

In particular, has defeat devices 40 proven, which by the between the drivers 5 on the pliers leg 3 ; 4 and a chain connector 21 or a trapezoidal nut 31 arranged medium driving means 25 respectively. 35 is formed, the opposite to the chain connector 21 or the trapezoidal nut 31 and the means of transport / s 5 on the thigh 3 ; 4 Defined movable by spring force is arranged.

As springs preferred compression springs, possibly also gas springs, with a travel of a few millimeters use. In particular, disc spring packages have 42 proven, which movable or "floating" example on an axis or similar leadership 41 can be stored between the takeaway 5 . 25 . 35 is fixed.

In the embodiment according to 3 to 8th is a medium driver 25 on the chain connector 21 arranged, which 21 - as the name implies - with the chain 20 connected is. By the middle driving means 25 becomes an axis 41 with a length pushed in such a way that on both sides of each plate spring packages 42 can be arranged. The ends of the axle 41 are each in takeaway 5 fixed, which firmly with the pliers leg 3 respectively. 4 are connected. Adjacent to the pliers leg 3 respectively. 4 arranged driver 5 , preferably at the ends of the axle 41 opposite side, are each an end or position switch 44 arranged.

The shutdown device according to 9 to 12 follows that too 3 to 8th described with the difference that the middle driving means 35 on the spindle nut 31 a trapezoidal spindle drive 30 is arranged.

In both embodiments, it can be clearly seen that due to the spring packs 42 in each case the average driving means 25 respectively. 35 defined movably is stored (in 6 respectively. 10 by double arrows above the spring packs 42 illustrated). By so far "floating" storage of the middle driving means 25 respectively. 35 this can change its position defined when unusual force peaks occur, depending on the design, for example, between 1 to 5 millimeters, in particular between 2 to 4 millimeters, preferably about 3 millimeters. At the middle driving device 25 respectively. 35 are now switching flags 43 arranged with a length such that these adjacent the switching contact 45 the end or position switch 44 end up. Now moves the middle driving means 25 respectively. 35 z. B. as a result of reaching an anchor point of the pliers legs 3 and or 4 so contact the ends of the switching flags 43 the appropriate switching contact, such as a switching roller (not shown in detail), the limit switch 44 which the drive 10 and 20 respectively. 30 off. Finally, it is also clearly recognizable that the above-described arrangement of a shutdown device 40 both in the positive and in the negative direction of travel of the pliers legs 3 ; 4 is trained.

With the inventive arrangement of a shutdown device 40 between each movable pliers leg 3 and or 4 and the drive means 20 respectively. 30 is an improved, in particular needs-based turn-off, mobility of a telescopic forceps 1 which avoids the safety disadvantages known from the prior art.

The shutdown device designed according to the invention reliably switches the electric motor with any detected force peak 10 from. In particular, a shutdown device designed according to the invention switches 40 the electric motor 10 even if only on a pliers leg 3 or 4 a force peak occurs. As when gripping a load 100 for the final position determination on the load 100 usually in the pliers legs 3 and 4 arranged additional switches such as shut-off have proven to serve the invention defeat 40 only damage avoidance esp. Due to incorrect operation.

By at the same time waiving a slip clutch is ultimately a self-locking chain drive 20 provided in which the drive means 10 and 20 the pliers legs 3 ; 4 even in the event that load 100 and pliers 1 get out of vertical position or against an obstacle 100 or 102 push together, hold together. In addition, the drive means 20 respectively. 30 switched off as needed, as soon as the procedure of the thighs 3 and or 4 the shutdown device 40 U.N ordinary force peaks detected. Such a need-based shutdown of the drive means 10 and 20 respectively. 30 avoids eventually when using trapezoidal threaded spindles 30 advantageous whose otherwise given deadlock.

1

Telescopic coil tongs

2

tong housing

3

first pliers legs

3a

Guide carrier of the first pliers leg 3

3b

Support arm of the first pliers leg 3

3c

Claw on the support arm 3b of the first pliers leg 3

4

second pliers legs

4a

Guide carrier of the second forceps leg 4

4b

Support arm of the second pliers leg 4

4c

Claw on the support arm 4b of the second pliers leg 4

5

Carrier / driver on the pliers leg 3 respectively. 4

10

electric motor

20

Chain

21

chain connector

22

chain tensioner

23

drive sprocket

24

pinion

25

Carrier / driver on the chain connector 21

30

Trapezoidal screw

31

Trapezoidal threaded nut

35

Carrier / driver on the spindle nut 31

40

Shutdown device for electric motor 10

41

Axis, guide

42

Belleville spring assembly; Compression spring, gas spring

43

Schaltfahne

44

end or position switch

45

Switch contact of the limit switch 44

100

Load; coil

101

Load axis; coil axis

102

fixed articles; masonry

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - US 4261609 A [0002]
• EP 0802146 A1 [0002]
• - DE 10225596 A1 [0006]
• - DE 10342063 A1 [0007]
• - DE 3632192 C2 [0010]
• - DE 0011406 [0011]
• - DD 129317 A1 [0011]

Claims (10)

Telescopic pliers ( 1 ) with - a pliers housing ( 2 ); and - a first ( 3 ) and a second ( 4 ) Pliers legs; - each pliers leg ( 3 ; 4 ) a management carrier ( 3a ; 4a ) and a support arm ( 3b ; 4b ); and - at least one pliers leg ( 3 ; 4 ) by means of its executive body ( 3a ; 4a ) in the pliers housing ( 2 ) is held in such a way that this via drive means ( 10 . 20 or 10 . 30 ) is movable by the drive means - one of an electric motor ( 10 ) driven chain ( 20 ) or - at least one of the electric motor ( 10 ) driven trapezoidal threaded spindle ( 30 ), with which the leg (s) ( 3 . 4 ) are in active connection via driving means; characterized in that between each movable pliers leg ( 3 ; 4 ) and the drive means (chain 20 or trapezoidal threaded spindle 30 ) at least two driving means ( 5 ; 21 . 25 respectively. 31 . 35 ) comprehensive shutdown device ( 40 ) for the electric motor ( 10 ), one of which is connected to chain ( 20 ) or trapezoidal thread spindle ( 30 ) arranged medium take-off means ( 25 ; 35 ) opposite the other one on the thigh ( 3 ; 4 ) arranged entrainment means / n ( 5 ) defined by spring force movable (or "floating") is stored or vice versa. Telescopic pliers ( 1 ) according to claim 1, characterized in that the shutdown device ( 40 ) by the between the drivers ( 5 ) on the pliers leg ( 3 ; 4 ) and a chain connector ( 21 ) or a trapezoidal nut ( 31 ) arranged medium take-off means ( 25 respectively. 35 ) formed opposite the chain connector ( 21 ) or the trapezoidal nut ( 31 ) and the means of transport (s) ( 5 ) on the thigh ( 3 ; 4 ) Is arranged movably mounted by spring force. Telescopic pliers ( 1 ) according to claim 1 or 2, characterized in that are used to generate the spring force compression springs. Telescopic forceps according to one of claims 1 to 3, characterized in that for generating the spring force plate spring packets ( 42 ) Find use. Telescopic pliers ( 1 ) according to claim 1 or 2, characterized in that the shutdown device ( 40 ) in both the positive and in the negative direction of travel of the forceps legs ( 3 ; 4 ) is formed switchable. Telescopic pliers ( 1 ) according to one of claims 1 to 3, characterized in that the mobility of the middle driving means ( 25 ; 35 ) between 1 to 5 millimeters; in particular between 2 to 4 millimeters, preferably about 3 millimeters. Telescopic pliers ( 1 ) according to one of the preceding claims, characterized in that the shutdown device ( 40 ) an addressable in positive as well as in a negative displacement direction end or position switch ( 44 ). Telescopic pliers ( 1 ) according to claim 7, characterized in that the end or position switches ( 44 ) adjacent to the pliers leg ( 3 ; 4 ) arranged driver ( 5 ) are arranged. Telescopic pliers ( 1 ) according to one of the preceding claims, characterized in that the shutdown device ( 40 ) a positive and a negative shift direction acting switching flag ( 43 ). Telescopic pliers ( 1 ) according to claim 9, characterized in that the switching flag ( 43 ) at the middle driver ( 25 ; 35 ) is arranged.