US 3800425 A
An indicating device for crane booms or the like, said device comprising a framework adapted to be fastened to a boom, a curved scale member connected to the framework with angular orientation, working radius and load capacity indicia thereon, and an indicator with a pointer thereon for coacting with the indicia to provide appropriate readings to the crane operator, the indicator being provided with a pendulum or weighted member to maintain it in the same angular orientation independent of the boom angle, such that when the boom position is changed, the curved scale member rotates with respect to the pointer, thereby providing clearly visible readings to the operator.
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Description (OCR text may contain errors)
' United States Patent [191 Haynie [4 1 Apr.2,1974
[ BOOM ORIENTATION AND LOAD CAPACITY INDICATOR  Inventor: Jack J. Haynie, Charlotte, NC.
22 Filed: Mar. 20, 1972 211 Appl. No.: 235,985
 US. Cl. 33/333, 33/399, 116/124 F  Int. Cl G0lc 9/12  Field of Search .33/333, 334, 370, 371, 33/372, 373, 391, 402, 401; 116/124 F  References Cited UNITED STATES PATENTS 2,835,220 5/1958 Rardin; 116/124 F 1,047,611 12/1912 Bradley 1 33/402 X 3,073,280 1/1963 Thiel 116/124 F 1,750,962 3/1930 Lichtenberg. 116/124 F 2,528,640 11/1950 Coleman ll6/D1G. 46
FOREIGN PATENTS OR APPLlCATIONS 112,979 H1926 Switzerland 33/401 Primary Examiner-Louis R. Prince Assistant Examiner-Charles E. Phillips Attorney, Agent, or Firm-Clarence A. OBrien; Harvey B. Jacobson  ABSTRACT An indicating device for crane booms or the like, said device comprising a framework adapted to be fastened to a boom, a'curved scale member connected to the framework with angular orientation, working radius and load capacity indicia thereon, and an indicator with a pointer thereon for coacting with the indicia to provide appropriate readings to the crane operator, the indicator being provided with a pendulum or weighted member to maintain it in the same angular orientation independent of the boom angle, such that when the boom position is changed, the curved scale member rotates with respect to the pointer, thereby providing clearly visible readings to the operator.
3 Claims, 7 Drawing Figures PATENTEDAPR 21974 3.800.425 sum 1 at 2 I Fig.
The present invention is generally related to material handling cranes, and similar machinery with angularly adjustable booms which move in a generally vertical plane. More particularly, the present invention is related to an improved indicating device for booms, whereby the operator may conveniently observe the boom angle, working radius, and load capacity at any time. This type of device is particularly useful when the boom operator desires to position a load repeatedly at the same location.
In the past, cranes and similar boom machines have been provided with indicating devices of various kinds for the purpose of informing the operator of boom angle, load capacity, or working radius. However, such conventional devices, for the most part, have either provided only a single one of these readings or have. been of such a structure and location as to render readings difficult or impossible for the operator to make while remaining inthe cab. Indicating devices which have been proposed for mounting in the operators cab have been of such construction to require that they be mounted far beneath the operators eye level, thereby making readings inconvenient and, often, inaccurate. More recently, proposed indicating devices which provide multiple readings of boom angle, load capacity, and working radius etc. include scales which are generally perpendicular to the operators line of vision, making it necessary for the operator to bend over or even leave his control station to make accurate readings.
Therefore, it is an object of the present invention to provide a novel boom indicating device which may be mounted directly to the-boom with a curved scale adjacent to the operators station, whereby the operator may easily and quickly observe the boom angle, load capacity, and working radius while maintaining his normal working position.
Another object of the present invention is to provide a unique indicating device including a pair of spaced, generally parallel, curved scale members with angle and load capacity indicia thereon which coact with an indicator extending through a slot separating the scale members, whereby both scales may be clearly read by an operator regardless of boom angle.
It is a further object of the present invention to provide a versatile boom indicating device which is rugged, durable, long-lasting, is comprised of a relatively small number of moving parts, and is economical to manufacture and maintain.
FIG. 5 is a sectional view taken along section 55 of FIG. 3.
FIG. 6 is a sectional view taken substantially along section 66 of FIG. 3.
FIG. 7 is a plan view of the scale members associated with the present invention when in a flat configuration.
Referring now, more particularly, to FIGS. 1 and 2 of the drawings, the indicating device of the present invention is generally indicated by the numeral 10 and is illustrated as being mounted to a boom 12 which is movable in a vertical plane about a pivot point 14 in a manner common with most conventional crane constructions. The indication device is provided with a curved scale 16 which is mounted adjacent and concave with respect to an operators station or cab 18. An indicator 20 coacts with the indicia on scale members 16, the indicator being mounted at approximately eye level and clearly within the operators line of vision to assure convenient andiaccurate readings.
The indicator is' provided with a support framework 22 which is fastened 'to the boom and which includes a pivotal connection at 24 for supporting indicator 20 and a pendulum or weighted'member 26. The pendulum is effective to maintain a substantially constant angular position of the indicator with respect to the horizontal independent of boom position. Thus, as boom 12 is raised or lowered as indicated by arrows 28 and 30, scale members 16 rotate with respect to indicator 20 to provide the proper boom angle, load capacity, and working radius readings.
With reference to FIGS. 3-6, the construction of the indicating device of the present invention may be seen in more detail. Preferably, support framework 22 is formed from steel or similar materials and is provided with a mounting flange 32 which is bolted or otherwise fastened to a mounting bracket 34, adapted to be fastened to the side surfaces of theassociated boom and provide sufficient clearancev between the boom and scale members 16. The upper portionof framework 22 is provided with a pair of support arms 36 and 38 which extend outwardly and terminate at a pair of curved back plates 40 welded thereto. The back plates are of relatively rigid construction and are arcuate in configuration to provide a firm mounting base for the overlying scale members 16 which are secured in position by way of wing nuts 42, or similar fastening means.
During initial installation, the scale members are of flat configuration and are bent into position on back plate 40 by fastening at one end with one of the wing nuts and then bending it down into position for fasten- These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
FIG. I is a perspective view of the indicating device of the present invention mounted to a typical crane boom adjacent to the associated operator station.
FIG. 2'is a side elevation of the boom indicating device of the present invention fixed to a typical crane boom. 1
FIG. 3 is a side elevation of the indicating device of the present invention. J
FIG. 4 is'a front elevation of the indicating device of the presentinvention.
ing with the second wing nut. Thus, the scale members may be made of relatively inexpensive flexible material and may be easily changed or replaced, as required. Since the back plates are of relatively rigid construction, proper curvature of each scale member is assured, thereby preventing interference with the indicator 22 during movement of the boom.
It will be appreciated that indicator 20 is comprised of an elongated member fastened at one end thereof to a rotatable shaft 44 by way of a collar 46 and associated setscrew 48. The shaft is rotatably supported by a bearing 50 associated with framework 22. Pendulum 26 is also affixed to shaft 44 by way of a setscrew 52 or similar fastening means. Thus, indicator 20 and pendulum member 26 rotate in unison with respect to the support framework when the boom angle is changed. Preferably, the weight of indicator is negligible with respect to that of pendulum or weight member 26, such that the indicator is maintained in a substantially horizontal position independent of boom angle.
The outer end of indicator 20 is provided with a pointer 54 having a pair of opposite tapered end portions which extend outwardly in overlying relationship with the indicia on scale members 16. The scale members are generally parallel to each other and are spaced apart to provide a slot 56 through which the elongated portion of indicator 20 extends, such that the scale members are free to move in an arc about the axis of shaft 44 without engagement with the pointer 54.
The indicia on scale members 16 is arranged to provide corresponding readings of working radius and load capacity for each angular position of the associated boom. This indicia is more clearly shown in FIG. 7, wherein the scale members are illustrated in their flat configuration prior to installation. It will be appreciated, that as the boom size or load capacity characteristics are changed, it is necessary to change only one of the scale members to provide the proper readings, it being unnecessary to change the boom angle scale member. A typical 40 foot boom scale member is illustrated and includes indicia which provide a 35 foot radius opposite of the 40 boom angle mark, together with a load capacity reading of approximately 26 tons. If the boom is raised to a 50 position, pointer 54 will align with this mark and the 30 foot radius mark, together with the 32 ton load capacity marking.
Since the scale members are convex in configuration and are adjacent to the operators station, accurate readings may be conveniently made by the operator as boom angle is changed. Furthermore, since pendulum 26 maintains the indicator 20 in approximately a horizontal position, independent of boom position, the change in position of pointer 54 with respect to the operator's eyes is minimized and is effected only by vertical movement of the boom. This means that the operator's line of vision to the pointer remains approximately perpendicular to those portions of the scale members underlying the pointer, regardless of the boom angle. This enhances the accuracy with which the indicating device of the present invention may be read.
The indicating device of the present invention may be constructed from various materials such as metals, plastics, or other materials well known in the art. Since the device is comprised of a relatively small number of moving parts, it is economical to manufacture and maintain. In addition, the scale members may be replaced or changed with a minimum amount of time and effort. The boom angle scale member may be utilized with nearly all boom constructions, with the other scale member being provided with indicia corresponding to the boom length and load capacity characteristics. Installation of the indicating device is relatively simple, such that the device may be positioned on the boom adjacent to the operators station to assure unhampered observation of the scale members by the operator when in his working position.
The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
What is claimed as new is as follows:
1. An indicating device for use with an angularly adjustable material handling boom, said device comprising a framework adapted to be fastened to the boom, a shaft rotatably supported by said framework, a pair of spaced, side-by-side parallel, arcuate scale members removably fastened to said framework and positioned with their centers of curvature at least closely adjacent the axis of rotation of said shaft, first indicia on the convex side of one of said scale members corresponding to the angular position of the associated boom, second indicia on the convex side of the other of said scale members corresponding to the working radius of the associated boom, an elongated arm, means adjustably securing one end of said arm to said shaft for adjusted angular displacement thereabout, adjustable positioning therealong and rotation therewith and with the other end of said arm extending and swingable through the space separating said scale members, an elongated pointer positioned, centrally intermediate its opposite ends on the other end of said arm with said pointer generally paralleling said axis and closely overlying the convex sides of said scale members and registrable with said indicia to provide boom angle and working radius readings, elongated pendulum means, means mounting one end of said pendulum means on said shaft alongside said one end of said arm and for adjustable angular displacement about and shifting along said shaft relative to said arm for rotation of said arm with said shaft to maintain said arm in substantially the same angular position relative to the horizontal independent of the angular position of the associated boom, the effective length of said pendulum means relative to said axis being less than the radial spacing between said axis and said arcuate scale members, whereby the free end of said elongated pendulum means may swing within the confines of said arcuate scale members if the orientation of the latter relative to the horizontal is such to allow the pendulum means to swing, by gravity, to a position within the confines of said arcuate scale members.
2. The structure set forth in claim 1 wherein said framework includes a pair of arcuate support plates in underlying abutting relation with said arcuate scale members, and removable fastening means associated with said support plates for readily securing said scale members thereto.
3. The structure set forth in claim 2 wherein said removable fastening means includes bolts at opposite ends of said scale member.