DE1191532B - Safety load indicator - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

B 66c

German class: 35 b-3/16

Number: 1191532

File number: A 41878 XI / 35 b

Filing date: December 14, 1962

Opening day: April 22, 1965

The invention relates to a safety load indicator in which with a mounted in a housing, pivotable lever in a certain angular position of the lever, a switch can be actuated, wherein the lever is tensioned against the actuation direction by a spring and can be moved in the actuation direction with a force that corresponds to the crane load is proportional, and in which in a device for reducing the crane load a dependent from the boom position controllable fulcrum is provided, which by means of a cam is adjustable with the boom.

The well-known safety load indicators, with which strong compression springs until the display is triggered are acted upon with different cable forces, create difficulties when the response point the display should be fine-tuned. It has therefore already been suggested using a strong leverage a much smaller and weaker spring with constant Operate voltage, because in this way the display always at a fixed amount of Spring tension takes place, regardless of the working radius of the crane. With a well-known Safety load indicators of this latter type were relatively small cams in a housing arranged concealed, so that cumbersome when operating the crane with different boom lengths Remodeling work were required, which also had the disadvantage that the relative small cam required a considerable manufacturing effort in terms of their accuracy. Finally, it is also known to provide two cam bodies in a safety load indicator, one of which is effective when the crane is unsupported and the other when it is supported.

The invention is based on the object of the second above in a safety load indicator Point to suggest the type with a small spring under constant tension for operation to make a minimum of conversions necessary with different boom lengths and that To make cam bodies easy to manufacture.

The object is achieved according to the invention in that the cam is fixed to a part of the Crane and the housing is connected to another part of the crane, which is relative to the one part Change of the boom angle is pivotable, and that at least one scanning device for control of the fulcrum protrudes from the housing, which is permanently in contact with the cam.

In a preferred embodiment of a safety load indicator

Applicant:

Robert Loudon Aitken, London

Representative:

Dr.-Ing. W. Höger

and Dipl.-Ing. W. Stellrecht M.Sc,

Patent attorneys, Stuttgart S, Uhlandstr. 16

, Named as inventor:
Robert Loudon Aitken, London

Claimed priority:
Great Britain 14 December 1961
(44 930)

Safety load indicator according to the invention is the housing through part of the boom rope pivotally mounted on an anchor pin of the crane and the cam is fixed to a non swiveling part of the crane connected.

The controllable fulcrum is expediently connected to one arm of an angle lever, which is mounted in the housing and which can be pivoted with its other arm over a rod is connected to a curve feeler lever, which in turn rests on the curve body curve feeler elements wearing.

Finally, with a safety load indicator according to the invention, the measure known per se can also be provided with advantage that two cam bodies are attached in a mutually parallel position on the non-pivoting part of the crane and a pair of cam sensing elements are provided for contact with the associated cam body, one curve sensing element is used when the crane is working in the supported position, and the other curve sensing element is used when the crane is operating in the unsupported position, and the curve sensing element used in the unsupported position is attached to a swivel arm and can be brought into a position not resting on the curve body .
The following description of a preferred embodiment of a safety load indicator according to the invention is used in conjunction with the drawings for further explanation. It shows

509 540/96

1 shows a side view of a safety load normal area of the path of the fulcrum roller 5

indicator, the downward force acting on the rotary

F i g. 2 shows a partial section of FIG . 1, point role is exercised via the angle lever 6,

Fig. 3 shows a section along line AA of FIG. 2, with a corresponding load on the rope 15

and 5 does not change very significantly. As shown in Fig. 2

F i g. 4 g of a section along line BB of F i. 2. is set, the path length of the fulcrum roller 5 is

A body part 1 of the safety load indicator is equal to the distance between this and the

pivotable on an anchor pin 30 of the crane pivot pin 7 of the angle lever 6 small while

arranged. In the body part 1 , the path of the fulcrum roller 5 is essentially one on a rotation

pin 33 an angle lever 2 is provided, one of which is a considerable length of the arm of the angle lever 2

Arm is connected to a return spring 3 , which covers that in contact with the fulcrum roller

tries to open a pair of contacts at is, and thus changes a movement of the fulcrum

which one fixed and the other of the angle roller 5 essentially the torque that on

lever is worn. the angle lever 2 around the pivot 33 around

The other arm of the angle lever 2 is flattened 15 is exercised.

and forms a path for a moving pivot point roller 5 is between the fork ends point roller 5, which also a second path is arranged on one of a rod 16, whose opposite second lever 6 touches, which is pivotable on a pivot end on an arm of a third winch 7 is pivotably arranged . The second lever lever 17 is arranged around a pin 18 lever 6 is also an angle lever, the second 20 of which is pivotable. With the other arm of the angled arm, much shorter than that in contact with the rotary lever 17, a rod 19 is connected, which is an arm located by point roller 5. an opening in the body 1 protrudes and pivoting

The short arm of the bell crank 6 is connected by a bar with a curve feeler lever 20 which

Pin 8 via a tab 9 and a tab pin 29 can be pivoted about a pin 31 on an arm.

connected to a lever 10. The lever 10 is arranged on 25 which extends away from the body 1.

a wedge sleeve 44 rigidly arranged, which is on a Aus F i g. 3 it follows that the curve feeler lever

Bolt 43 is held ( Fig. 4). 20 has a U-shaped cross section and two

The bolt 43 extends over the body curve feeler arms. These will take turns

part 1 and is used in its outer ends to operate the indicator, and

eccentric lugs 42 provided, which on over 30 depending on whether the crane is supported or

support plates 12 are arranged. The other ends are unsupported. A curve sensor arm

The transfer plates 12 have a pin 13 that is on 21 for operation with the crane unsupported

which a pulley 14 is rotatably arranged. A pivotally mounted on a pin 22 and

Part 15 of the boom rope runs around the pulley is held by a bolt 23 while a

14 around and transfers to the transfer plates 35 curve sensor arm 21a for operation with a supported crane

12 a force which is arranged rigidly on the curve feeler lever 20 by the tension of the part 15.

depends. The curve feeler arms 21 and 21a carry feeler members

The eccentric approaches 42 are in bearings 24 and 24 a, which the fixed curves 25 and 25 a

held, which are arranged in a housing 41 , follow.

which is welded to the transmission plates 12 , 40 To now the curve sensing elements in contact with

while the middle part of the lugs 42 in bearings to keep the curves, a spring 26 is connected to the

45, which are welded to the body 1. connected to the bell crank 17, and this spring

As can be clearly seen from Fig. 2 , the attempt is made to attach the tab 19 against the curves

Also press transfer plates 12 over soft buffers.

the body 1 via a angeord- in the body 1 45 In general, the length of the curves 25 depends

Neten pin 50 connected to an undesirable loading and 25 a of the distance of the curves from the

To prevent movement of the transfer plates 12 , anchor pin 30 to which the curve sensing elements

if the connection to the boom part is interrupted 24 and 24 a rotate, and also from the angle,

will. around which the plate transmitter 12 when actuated

It should be noted that the voltage in the 50 of the crane must be turned. For any be rope 15 the bolt 43 tries to rotate so that the correct angular movement of the curve sensing elements about the axis of the eccentric lug 42 against the line of the anchor pin 30 results in the curves being drawn around which the centers of the anchor pin 30 are longer can, the greater the distance between and the pin 13 connects. This will see the curves and the anchor pin 30 is. The lever 10 (FIG. 2) is rotated approximately clockwise by the length of the curves, bolt 43 in this invention. Since the lever 10, as described above, as the accuracy with which the cam notch is connected to the angle lever 6 , results in the surface must be machined, and this movement relates to a rotation of the angle of its length. In general, it is the case that the hebeis 6, as a result of which a downwardly directed pressure, the lower the accuracy in production, the longer the curves are, the smaller the fulcrum roller 5 and thus also the 60. The actual arm of the angle lever 2 is exercised , which is in loading distance and thus the length of the curve is naturally in contact with the fulcrum roller 5 . determined by the distance on the crane

The instruction is in contact with the fulcrum roller 5 to the mechanism of the

Sensitive arm of the angle lever 6 is to be included in the comparison safety load indicator. But was

to the other arm of the angle lever 6, which found in 65 that the distance from the curved surface

substantially equal to the distance between the anchor pin and expediently between 6 and

Pivot pin 7 and pin 8 can be 24 inches. This is an important factor

moderately long. It follows, therefore, that in reducing the cost of the security burden

indicator. Up until now it was necessary to produce the curves individually for a specific crane to which they were then adapted, and this resulted in a lengthy and expensive examination of the device. However, with the present construction it is possible during manufacture and assembly of the safety load indicator three curves on the crane exactly with respect to the safety load indicator with the help of an adjustment device and thus the use of curves allow whose curve shape is determined by calculation or by information, as it was from earlier Cranes of the same type were obtained.

The curve sensing lever 20 carries a switch 27 which is closed when the Kurvenfühlarm 21 in its retracted position 21 R is (shown in phantom).

The curve 25 for operation with the crane unsupported has a higher shape than the curve 25 a for operation with the outrigger crane because the crane has a lower load in the unsupported one Can carry position, so that at a certain radius of the crane the fulcrum roller 5 further from the Center of the pivot 33 is considered to be in the supported state. So that the curve sensing element 24 for Operation with the crane unsupported, the curve sensing element Drive over 24α for operation with an outrigger crane. The switch 27 can be used to indicate which cam track is working and as the Curves 25 and 25 a are readily visible and can be clearly marked without further ado, A check can be made to ensure that the correct curve is present on the subject Condition of the crane is in operation. Also, the change is between supported and unsupported state very easy to carry out with the safety load indicator according to the invention, and it is therefore less likely that the operator will notice the need for Setting of the indicator neglected.

If the crane is to be provided with different booms or with boom extensions appropriate curves can be prepared and provided, and these are then clearly marked so that just by looking it can be determined that the correct curve for the particular boom arrangement is used. Here, too, the setting can be carried out very easily since fixing the curves in an outer layer enables them to be easily can be exchanged.

If additional information regarding the load on the crane is required, additional switches can be attached and actuated by moving the angle lever 2. Typically for this purpose, a switch 4 α is shown in the embodiment, which works in the opposite direction to switch 4, so that a stop piece 28 holds the switch 4 a open when light loads are carried, and a light then goes out to indicate that the Burden approaches the security burden.

Claims (4)

Patent claims: 1. Safety load indicator, in which with a pivotable mounted in a housing Lever in a certain angular position of the lever, a switch can be actuated, the Lever is tensioned by a spring against the direction of actuation and is movable in the direction of actuation with a force that the Crane load is proportional and in which in a device for reducing the crane load depending on the boom position controllable fulcrum is provided by means of a cam is adjustable with the boom, characterized in that the cam (25) fixed to one part of the crane and the housing (1) to another Part of the crane is connected to the relative to a part when changing the boom angle is pivotable and that at least one scanning device (24, 19) for controlling the Fulcrum (5) protrudes from the housing (1), which is permanently attached to the cam (25) is present. 2. Safety load indicator according to claim 1, characterized in that the housing (1) mounted pivotably on an anchor pin (30) of the crane by part of the boom rope (15) and the cam (25) is firmly connected to a non-pivoting part of the crane is. 3. Safety load indicator according spoke 1 or 2, characterized in that the controllable Lever pivot point (5) is connected to one arm of an angle lever (17) which is in the Housing (1) is mounted and which can be pivoted with its other arm via a rod (19) a curve feeler lever (20) is connected to the curve feeler members (24) on the curve body (25) are in contact. 4. Safety load indicator according to spoke 3, characterized in that two cam bodies (25, 25 a) are attached in a mutually parallel position on the non-pivoting part of the crane and a pair of curve sensing elements (24, 24 a) for contact with the associated curve body (25, 25 a) are provided, a curve sensing element (24 a) being used when the crane is in a supported position Position works, and the other curve sensing element (24) is used when the crane is working in the unsupported position and the curve sensing element (24) used in the unsupported position on a swivel arm (21) attached and can be brought into a position not resting on the cam body (25). Considered publications: German Auslegeschrift No. 1115 898,
679; German utility model No. 1785 382;
British Patent Nos. 723 070, 386 655. 1 sheet of drawings 509 540/96 4.65 © Bundesdruckerei Berlin