DE2060835A1 - Safety load display device for a crane or the like with an extendable boom - Google Patents

Description

PATENT ADVOCATE STUTTGART

A 11 138

5th December 1970

TSE B & A ENGIHEERING COMPANY LIKEiCED Menzies Road, Fonavood Industrial Estate, Hastings, Sussex / England

Safety load display device for a crane or the like. With an extendable boom

The invention relates to a security device for Cranes, especially Slcherheitala ^ t-sinEeigeTorriohtungan for cranes and the like with an extendable trailer "

- 2 109826/1063

A ΛΛ 158

5th December 1970

For safety load indicators for cranes with It is known for fixed length booms to provide an indicator where one of the crane load (including the weight of the hoist itself) derived force against the resistance of a spring or other means acts to operate an alarm device, the great dee resistance at which the alarm device is actuated, is invariable and the magnitude of the load-derived force, which is necessary to overcome this resistance is required, is changed after hating the working radius of the crane.

A known method of compensating the safety load indicator for changing the working radius is explained in British patents 723,070 and 1,191. In these two constructions , a composite lever system is used in which a movable pivot point is provided in connection with a pair of articulated levers , on which the metal-derived force or the resistance force act - in one construction by means of a tension spring and in the other by means of a pressure indicator. The position of the movable pivot point can be adjusted according to the boom angle (which in a crane is nit

109826/1063. ₅ _

2080835

A 11 138

5th December 1970
id ©

a boom of invariable length depends on the working radius) or by means of various designs the working radius gauges are changed, such as this is described in British patent specification 1,185,190.

Recently, more and more jib cranes are used in which the jib is raised or lowered by means of a hydraulic fluid piston or several hydraulic fluid pistons.

Hit this type of crane, the maximum safety load that can be lifted with the boom fully retracted can be many times greater than the maximum safety load that can be lifted with the boom fully extended. Dia An * ahl the rope parts from the jib tip to the sram winch block can be large when the jib is fully drawn in, and it can be quite small when it comes to outsourcing is fully extended. As a result, it is not desirable to use the load-derived force for transmission to the safety load indicator

See rope below, as below various modifications 109826/1063 _Ä

ORIGINAL BATHROOM - 4 -

A 11 138

5th December 1970

must be merged to allow the security load indicator to hate the number of Rope parts between the boom tip and the winch block can be adjusted,

It is more pertinent “the required load derived Power from the hydraulic one or more supporting the trailer Piston, and it is convenient to set up the indicator so that it points to the hydraulic Pressure responds, which actuated the pressure piston

The action of the piston or pistons on the boom must counteract the load moment including the boom weight itself around the boom axis of rotation are-3 a i.usleger supporting piston located close to the Außlegerdrehachse) he angle swinchen piston and boom varies considerably with the boom angle "'Oa& efficient _s AEEN boom" in view of the practical limits for the linear expansion of PlussIgkeitsdruckkolben each do must! Supportive moment vim the off! e ^ eie-Drahachse changes

1 0 9 8,>f> ι \ ν Ij 3

BATH ORIGINAL

AU 138

5 «. · December 19? 0

therefore strongly with the boom angle independent of the hydraulic pressure. It follows that everyone &5.cheii; s} aet ~ display3r. _> which is actuated by a force derived from the hydraulic pressure in a support piston »requires means which respond to a change in the boom angle in order to change the effect of the derived Kx'affc in such a way that it is proportional to the support element about the boom axis of rotation . An indicator with such a correction responds when the K:? An is in equilibrium, immediately to the load moment about the boom axis of rotation.

Usually this is the safety burden for a crane with a special working radius determined on the basis of the load, at which the crane would tip over, and accordingly by the load torque caused by the support base of the Crane's approved pivot point. " When, as in most cases, the boom pivot axis is not vertical over the bom Pivot point lies ^ t, then that moment is the crane tries to tip over from the moment around the boom axis of rotation different furthermore the difference depends on that A:? Boit radius of the crane. Therefore, if it is required that the maximum security load (the nominal load) for

109826/1063 _{BAD 0RiGINAL} _ ₆ _

A 11 138

5ο December 1970

a crane as the moment around the through the base of the crane corresponds to a certain pivot point, which is in an unchangeable relationship to the overturning moment, it is required, responsive to the working radius of the crane Introduce funds into the safety load indicator, thereby making a further appropriate correction of the load-derived Force can be applied

Ebanso other corrections can be introduced, if different or additional factors determine the maximum safety load »For example do On some cranes there is the extra stress when using the boom in an extended position Position desirable that a smaller load is lifted than when using smaller boom lengths in spite of Activity at the same working radius, and therefore can In this case, it may be necessary to incorporate means in the indicator which respond to the change in the extension of the boom speak to.

According to the invention is therefore a safety load display device for a crane odor the like. With a supported by means of a liquid pressure piston, extendable

I 0 9 8 2 6 / .1 C) B 3 - 7 ~

A 11 138

December 5, 1970

Boom provided, which a composite lever system with a pivotably mounted, triggering a warning signal when a predetermined angular position is reached first lever which is subjected to a drag force in order to move to this angular position counteract this with a second pivotably mounted lever on which a load-derived force acts, and with means for transmitting the force applied to the second lever to the first lever, in order to exert a moment on this, and which is characterized in that the load-derived force, the acts on the second lever, is derived from the hydraulic pressure of the pressure piston, and that the The device has first means which respond to a change in the Kraa working radius or the extension of the boom, and second means responsive to a change in boom angle which cooperate to to change the full moment exerted on the first lever in such a way that a warning signal is issued when the Maximum safety load for any combination of crane work .? adius or boom extension and boom angle is triggered »

- 8 ■ · 1 0 9 8 2 6/1 η 6 3 bad ORIGINAL

A 11 158

5 December 1970 i-there

Venn Ban converted this device into an indicator of the type described in British Patent 723 070 is installed, the force derived from the pressure of the fluid pressure acts on the first reinforcing lever, and the cam is usually on the Modification of the boom angle rotated accordingly · The guide curve of the cam is selected in such a way that it results in the correct multiplication factor for the warning signal to trigger when the nominal load is reached for different suspension angles at a given radius · One The spring attached to the wide reinforcement lever produces an auxiliary torque about its axis of rotation Fastened lever, the position of which is controlled by a cam that rotates according to the crane radius will. The guide curve of the cam is designed in such a way that the force exerted on the spring changes by to transfer the desired correction to the second reinforcement lever for the nominal load at this radius If the rated load is limited for long boom extensions, a compensation factor can be added by deviation are introduced by the theoretical guide curve of the cantilever angle cam and / or the radius cam,

109826/1 063 _ 9 ..

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2060 * 35

A 11 158

December 5, 1970

id

but this can have the consequence that the crane suffers a loss of performance with smaller boom repairs. In a modified embodiment, the Cam, which controls the position of the pivoted lever ·, according to the boom retraction instead of Boom radius rotated.

Similarly, the τοη des Pressure of the liquid pressure piston * derived force applied to the composite lever system and the τοη the Correction spring generated force - as explained below was - transferred to the second reinforcement lever, bo that a correction of the force applied by the first lever is effected. This right moment of the wide lever acts on the hydraulic unit, which old the pressure gauge and old Varnsdtteln ia Cab is tied.

An embodiment of the invention is described with reference to the drawing, which shows a view of a safety load indicator for a crane bit an extendable, by means of at least one fluid pressure piston

109826/1063 _{BAD 0H1G1NAL}

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- ίο -

A 11 138

5th December 1970 i-there

supported Auelegerana shows.

The drawing shows an indicator that responds to the fluid pressure of a hydraulically operated pressure piston. Biegsaae llüsaigkeltsrohre 1 and 3 are old the oil at the top or as the bottom of a boom supporting pressure piston or a boom supporting pressure piston directly and bit actuating glides 6 and 7 in connection, which are in the built in the öehäuee 5 of the indicator cylinders 2 and 4 are performed. The actuators 6 and 7 rarely act on a lever 8 on a pin 9 opposite to which the lever 8 is placed. The distances το «pins 9 in which the actuators work are proportional to the areas at the top or bottom of the crane pressure piston» and therefore the moment on lever 8 is the force exerted by the pressure piston on the boom »Proportional. Sin StSBeI 10 is connected to the lever 8 and is articulated in a freely pivotable manner on a lever 11, which in turn is articulated in a freely pivotable manner on a bolt fastened in another housing 13. The plunger 10 transmits the medium

Actuating members applied to the lever 8 · original

109826/1063 ^B

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i! ! "is :: επ: ' ¹ Trifvt ^

- 11 -

A 11 138

December 5, 1970

Moment on the lever 11. An actuating lever 14 is freely pivoted at 15 in the housing 15 and operates in conjunction with the lever 11 via driving Unger coils 16, the position of which is con- trolled by the cam lever φ 17th The roller of the cam lever 17 moves inevitably on the surface of the cam 18, which is moved via lever 20 and axis 19 by means of gaskets which are influenced by the change in the boom angle. The rotation of the lever 14 counteracts a pressure rod 2Λ which, when a certain, preselected moment is applied, bends around the bolt 15 in such a way that the lever 14 switches 22a and 22b, which trigger a warning signal when the rated load of the crane is close to is reached or exceeded.

This results in a moment derived from the hydraulic pressure of the pressure piston acting on the lever 11 is transmitted directly, and that the torque transmitted from the lever to the lever 14- sur actuation of the warning device is controlled by the rollers 16, which are operated by means of the boom bracket

A rod 23 is at one free end of a spring 24-

109826/1063 -12-

BATH ORIGINAL

A 11 158

5. DeBeeber 1970

attached, the other end of which on an adjustable abutment 2J? that is at the end of the cam roller lever 26 is fastened freely pivotable at 27 in a further housing 28. The caster of the lever follows the guide curve of the cam 29, which is rotated via lever 31 and bolt 30 with Kittel, which on a Address change in crane operating radius. The radius can be derived from an independent mechanism as described in British Patent No. 1,183,190 is · Accordingly, becomes a dependent on the Eranradius Transfer the correction torque to the operating lever

The guide curve of the cam 18 is milled so that with a preselected nominal load with the corresponding radius, but with different boom angles - and therefore boom extensions - the positions of the rollers 16 are such that the desired moment is generated on the lever 14. Then the crane becomes a changed working radius with the corresponding one Moved nominal load and cut the guide curve of cam 29, until the force exerted by the spring 24 in connection with that on the lever 14 via lever 11 and

1 0 9 3 2 6/1 Π G 3

- 13 -

- 13 -

j A 11 138

\ 5 December 1970

j i-4a

Rollers 16 already applied Hoeerit is sufficient »um the closing of the contacts 22a and 22b su cause «The» the crane working radius is repeated for an area, τακ the leading curve of the squat 29 independent of νβΓΤΟ11.

As stated earlier, in beetijuiten _; Cases, the lever 31 in coordination "it the Auelegerer- [stretching are operated, and below this,""end,bit" \ means of generating a swirling motion proportional to the Auslegererstreokung of a gearbox or other means from a cable drum, the wire rope is attached to the boom tip «If necessary, the rope can be guided over a guide roller on or adjacent to the I boom axis. When also lamer the lever; 31 is actuated depending on the extension of the boom, the Noeken 18 is activated with a constant extension of the boom · * \ kung instead of constant working radius and the

I cut cam 19 so that the appropriate moment

₍ ^: on the lever 14 with different boom extensions

[is generated ·

In one of the described examples opposite

\ modified execution form is provided that under

! 109826/1063 .14-

A. 11 138

5. Deieeber 1970

Depending on the circumstances, 18 and 29 curl the boles 19 and 30 through the use of differently cut ones Means are rotated, which on the crane working radius bew · respond to the Auelegerwinkel. In this way, the position of the rollers 16 is dependent on the crane working radius and the force Ton applied to the lever 14 via the lever 23 is dependent on the lifting angle. Which The result of this modification is that with certain cranes it has been found that the calculated profile of the driving squat is more uniform is "Uniform crouches are easier to cut precisely than crouches with large changes in radius" The modified device is only to be used for cranes where this application results in more uniform squats.

109826/1063

Claims (1)

^: "* '^{; ι} ""'! Ommrrsf. i ι -15- A 11 138 5 December 1970 Claims 1. Safety load indicator device for a crane or the like. With a by means of a liquid draft flask supported, extendable boom, which has a composite lever system with a pivoted, has a warning signal triggering the first lever when a predetermined angular position is reached, who is subject to a contradiction to the To counteract movement to this angular position, with a second pivotably mounted lever which a load-derived force acts, and with means for transmitting the to the second lever applied! force on the first lever to access this exercising a moment characterized that the load-derived force acting on the second lever from the hydraulic Pressure of the pressure piston is derived, and that the device aufweiet first means that on 109826 / 10B3 - 1 6 - A 11 138 5 December 1970 a change in crane working radius or boom extension respond, and second means responsive to a change in boom angle, which cooperate to change the full moment exerted on the first lever such that a warning signal when the safety maximum load is reached for every combination of crane working radius or boom extension and hoist angle will. 2. Vorrichtun g according to claim 1, characterized in that the first means or the second means comprise a movable axis of rotation, and the second lever between the first lever / for the transmission of the force from the second lever to the first lever is arranged such that the first lever is rotated against this resistance force, the position the axis of rotation is controlled by a pivoted lever equipped with a cam roller which is operated by a cam that rotates ßicli by responding to the change in the crane's working radius or the extension or the 1 09 3 ? B / 1 i'b3 ~ 17 ~ 138 5th Bezeabeor 1970 * Device according to claims 1 or 2 ». characterized gekenaseichnet that the first or "wide el means» · Spring eiaechlie ^ - eon, dl "neinrt a KeaJtt with the first lever," the Zugjtraft the T * UEMs> wild means else · »chwenkber gelegerten Hebele geSnderfc ,, the an "ockenrolle aiii knows" on which a buck eiowiÄt, which is turned, while ear "uX the indertmg of the crane work" radius or the Auelegererstrectimg i "Jall the ereter" means or on the loading of the boom * winkeis ia Islle ü "R " broad mean eneprient. 1Q9826 / 10 & 3 • «J? Read the page