GB1282627A - Overload safety device for jib cranes - Google Patents

Overload safety device for jib cranes

Info

Publication number
GB1282627A
GB1282627A GB46356/69A GB4635669A GB1282627A GB 1282627 A GB1282627 A GB 1282627A GB 46356/69 A GB46356/69 A GB 46356/69A GB 4635669 A GB4635669 A GB 4635669A GB 1282627 A GB1282627 A GB 1282627A
Authority
GB
United Kingdom
Prior art keywords
jib
slider
potentiometer
voltage
radius
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB46356/69A
Inventor
Ludwig Pietzsch
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE19681803457 external-priority patent/DE1803457C3/en
Priority claimed from DE19681810639 external-priority patent/DE1810639C3/en
Priority claimed from DE19691903493 external-priority patent/DE1903493C3/en
Application filed by Individual filed Critical Individual
Publication of GB1282627A publication Critical patent/GB1282627A/en
Expired legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B66HOISTING; LIFTING; HAULING
    • B66CCRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C23/00Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
    • B66C23/88Safety gear
    • B66C23/90Devices for indicating or limiting lifting moment
    • B66C23/905Devices for indicating or limiting lifting moment electrical

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Jib Cranes (AREA)
  • Control And Safety Of Cranes (AREA)

Abstract

1282627 Safe-load indicator for cranes L PIETZSCH 19 Sept 1969 [16 Oct 1968 23 Nov 1968 24 Jan 1969] 46356/69 Heading G1N An overload device, Fig.1, for a jib crane comprises a plurality of strain gauges in a bridge 8 to produce a first voltage indicative of jib loading, and an arrangement which displaces the slider 4 of a potentiometer 3 in accordance with jib radius (horizontal projection of jib length), the potentiometer having a plurality of supply connections, C1 to Cn, to each of which a supply voltage is fed through adjustable switches S 1 to S n which supply voltages represent the maximum values of jib loading permissible for the respective actual values of jib radius corresponding to positions of the slider when set to the respective tapping points of the potentiometer. The slider voltage is compared with the first voltage by a discriminator 10 which actuates a relay 11 when the voltages are equal to actuate an alarm or switch off the crane. An arrangement for indicating jib radius Fig.5, includes a lead-screw spindle 11' rotatablymounted orthogonally of the axis of a telescopic jib 1', a nut 13' on the spindle, fixed against rotation, but movable longitudinally of the spindle when the latter is rotated by pulley 7' and cable 10' due to extension of the jib. A pin 18' extends from the nut to support an end of a rod 16' of which the other end is fixed orthogonally of a sleeve 17' slidable longitudinally of a pendulum bar 15', which pendulum is suspended from a fixed point 14 on the spindle axis. A rope 20' is fixed at one end to the sleeve and at the other to the drift shaft 19' of a potentiometer slider 4. Thus the distance a' between the point 14 and the sleeve varies as the jib radius lsinα where 1 is jib length and α is the angular displacement of the jib from the vertical. Alternative arrangements for indicating jib radius are illustrated in Figs.6, 7, 8 (not shown). Fig.4 (not shown) illustrates a circuit for compensating the jib load signal for variations caused by tilting of the jib. Fig.3 illustrates an alternative circuit to that of Fig.1 for use with a crane having a telescopic jib and incorporates a sine potentiometer R sα the slider 23 of which is driven by a jib angle α measuring device W, the potentiometer output voltage U α being fed to resistances R 1 , R 2 and R L in series of which R L is a potentiometer of which the slider 24 is operated by the output shaft 25 of the jib length measuring device L. So voltage U L at slider 24 is a function of lsinα where 1 is jib length. A reference voltage Ur corresponding to the position of slider 4 is taken from the slider 26 of a linear potentiometer R R across which a constant supply voltage U o is connected through resistors R 3 , R 4 . The differential voltage U L -U r is fed through an amplifier 27 to a motor M which operates sliders 26 and 4 to bring U r into equality with U L so that the slider 4 is automatically adjusted proportionally to jib radius.
GB46356/69A 1968-10-16 1969-09-19 Overload safety device for jib cranes Expired GB1282627A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19681803457 DE1803457C3 (en) 1968-10-16 1968-10-16 Overload protection for jib cranes
DE19681810639 DE1810639C3 (en) 1968-11-23 1968-11-23 Overload protection for telescopic cranes
DE19691903493 DE1903493C3 (en) 1969-01-24 1969-01-24 Overload protection device for telescopic cranes

Publications (1)

Publication Number Publication Date
GB1282627A true GB1282627A (en) 1972-07-19

Family

ID=27181542

Family Applications (1)

Application Number Title Priority Date Filing Date
GB46356/69A Expired GB1282627A (en) 1968-10-16 1969-09-19 Overload safety device for jib cranes

Country Status (2)

Country Link
US (1) US3638212A (en)
GB (1) GB1282627A (en)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2004041C3 (en) * 1970-01-29 1975-10-09 Ludwig Pietzsch overload protection for jib cranes, especially telescopic cranes
US3740741A (en) * 1971-05-26 1973-06-19 Eaton Corp Alarm set point control system
JPS5413651B2 (en) * 1971-12-29 1979-06-01
US3872458A (en) * 1971-12-31 1975-03-18 Savely Solomonov Schedrovitsky Crane boom-out transmitter
US3823395A (en) * 1972-05-30 1974-07-09 Trans Sonics Inc Remote condition indicator for load-lifting device
US3826321A (en) * 1973-05-25 1974-07-30 Trans Sonics Inc Load weighing system for cranes with rotatable booms
JPS5410123Y2 (en) * 1973-10-30 1979-05-11
GB1456174A (en) * 1974-03-04 1976-11-17 Shimizu Construction Co Ltd Alarm apparatus for the operaint range of cranes
JPS5339504Y2 (en) * 1974-03-05 1978-09-25
FR2282399A1 (en) * 1974-08-20 1976-03-19 Strawson Hydraulics Ltd SAFETY DEVICE FOR CRANES
US4752012A (en) * 1986-08-29 1988-06-21 Harnischfeger Corporation Crane control means employing load sensing devices
US5209361A (en) * 1991-10-31 1993-05-11 Grubb Jr Lloyd T Multiple-cable lifting head with load weighing mechanism for aerial booms and cranes
US10514234B2 (en) 2013-03-27 2019-12-24 Nostromo Holdings, Llc Method and apparatus for improving the aim of a weapon station, firing a point-detonating or an air-burst projectile

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2330060A (en) * 1941-10-28 1943-09-21 Gen Electric Safe load indicator for crane hoists
US2858070A (en) * 1955-11-17 1958-10-28 Scharff Leon Moment computing and indicating systems
US3200963A (en) * 1963-07-05 1965-08-17 Laszlo G Vermes Moment comparator

Also Published As

Publication number Publication date
US3638212A (en) 1972-01-25

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee