US 2805479 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
L W. DROSTE WORK TABLES FOR SHEET MATERIALS Sept. l0, 1957 Filed OG'I'.. 12, 1953 Louis W. DRosTE WORK TABLES FOR SHEET MATERIALS Louis W. Droste, St. Louis, Mo.
Application ctober 12, 1953, Serial N 385,32)
7 Claims. (Cl.r 33 80) This invention relates'to improvements in work tables for sheet materials, and more particularly to improved straight-edge manipulating apparatus, particularly but not exclusively adapted for ease of manipulating a movable edge member utilized for marking, scoring or cutting sheet materials, for example sheetmetal, incident to the fabrication of metal shapes, ducts, tubes and many other sheet metal products.
This applicant is aware of many of the numerous provisions for the general purpose of assuring parallelism of a straight-edge member incident to movement thereof across a work surface. Many such devices have been utilized in connection with drafting boards and other tables for various kinds of Work on sheet materials. However, exhaustive investigation of such devices'now available to the trade, reveals an utter lackVV of equipment for the purpose noted which may be considered fully reliable for its intended purpose, or'iffairly accurate, such available equipment is of inordinately high cost and available only for use on tables of predetermined'dimensions. Further shortcomings of existing equipment include, besides extremely high rst cost, excessive weight and hence excessive shipping and handling costs. It is accordingly a major and general objectiveof the present improvements, to realize a low-cost precisionmechanism for use in cutting, scoring or marking sheet materials, and which is not dependent upon nor solely adaptable to tables of only certain critical dimensions.
A further and important objective of they present improvements is realized in apparatus which may be produced and sold in the form of packaged, more or less standardized units, capable of attachment to a'work table at the situs of table usage.
Yet another highly important objective of the present improvements is realized ina straight edge traversal mechanism which, when fitted to a given table, will not obstruct the major area of such-table in any manner to preclude its usage for normal bench orother work, and hence serves to minimize floor space requirements incident to the equipment of arsheet metal shop with precision and modernized cutting, scoring or marking facilities.
Yet another general objective of the present improvements is realized in a low cost straight-edge traversing mechanism which is constructed almost entirely of readily available stock materials without the requirement of expensively tooled items; the traversing mechanism beingY inherently of simplied design, hence readily serviced by anyone without speci-al skill, and which isof a rugged character so as to be operable' for' indenite periods of time Without service expense of any kind.
The foregoingV and numerous other objectives and advantages will become more apparent from a'consideration of the following detailed descriptonof a'preferredy embodiment, particularly when considered'in connection with the accompanying drawings, in'which:
Fig. l is a top or plan view of a rectangular work table equipped according to thepreseut` improvements;
Patented Sept. 10, 1957 Fig. 2 is an end elevational view, somewhat enlarged and foreshortened, of the structure of Fig. l;
Fig. 3 is a further enlarged sectional view in a vertical Fig. 7 is a fragmentary sectional view as taken alongV line 7 7 of Fig. 1.
Referring now by characters of reference to the drawing, and rst to Fig. l, there is shown a table top TI of a conventional generally rectangular shape. Without restriction, the table top TT is of conventional wood construction, Which will usually include a plurality of Wood sills S, together with table legs TL.
Assuming for example the table to be particularly adapted for layout work on lsheet metal, it is a great preference to provide a plurality of graduated metal measurement and abutment strips. One such strip indicated, in 10, is fixed in position along the frontal margin 11 of the work table, assumed to be that margin nearest the operator. The fixed straight edge and abutment piece 1i) is by preference provided with indicia and graduations 12` in such manner that, since the strip 10 is disposed to project above the planar surface of the table top to the extent of its thickness, the margin'of the strip may serve as an edge abutment for the work piece. A similar parallel graduated strip 13 is mounted upon the table along the back or rearmost margin 14 of the table top, while similarly graduatedstrips 15 and 16 are located along and parallel to the side margins of the table.
A linearly graduated traversable straight-edge member 20 is provided with indicia and graduations 21. Since it is highly desirable, in fact necessary for precision work, that `as the straight edge member 2t) is traversed between the elements 10 and 13, the member 20 must be kept accurately parallel at all times to the abutment members 19 and 13. For this latter purpose there are provided a pair of straight-edge traversing units, one arranged `along each of the opposite side margins of the table top'T, as Awill now be described.
Since these units are or may be identical in construction, or substantially so, that unit disposed along the right hand margin (Fig. l) is selected for description, and includes a frame structure through which the traversing unit may be attached to or removed from a table While the unit is virtually completely assembled.
This facility comprises a sectional frame, a major section of which consists of an angle member 25, depending from the rear end region of which is a bearing arm Z6, for a purpose later appearing. At the opposite end of the frame, section 25 is an L-'shaped member comprising a slotted horziontal leg 27, the slot in which is indicated at 30, and a depending portion forming a second bearing arm 31. The slot 30 receives a screw 32, which, in coaction with the slot, enables a length adjustment of the frame 25 27.
The lower end of member 31 carries a stub shaft 33 rotatively supporting a pulley 34, trained over which is av ilexible band shown as including a lower pass 35 and an upper pass 36. The band 35 36 should be understood to consist of any suitable ilexible power transmission element of the general naturey of a cord, wire band, tape or other so-called endless member, which in practice Vconsists ofia high-tensile low-stretch cord, or a wire.
By length adjustment of they frame elementsV and the table width may be accommodated. For example, it is desired that the straight-edge member 2i) be moved close to the frontal margin 11 of the work table in order to take advantage of all work area. To assure this' movement of member 20, the frame 25-27 `may be adjusted lengthwise within limits determined. byithe`dimension of elongate slot 30, which in turn may require an adjustment of the length of band 35S-36. For instance, suppose the table is slightly wider than the length ofrframe section 25, inA which case the screw 32 is loosened and frame section 27 is slidably adjusted longitudinally through the coaction of slotY 30 to move pulley 34'forwardly. This frame adjustment will enable member 20 to be moved a 'greater distance in a forward direction, and hence moved closer to the front margin 11; Of course, the length of band 35-36 may be adjusted as to length to permit this frame adjustment. The frame 2527, in addition to being adjustable to accommodate the table width, may be similarly adjusted to vary the tension in band 35-36.
The bearing arm 26 serves through a shaft hereinafter described, to carry a winding Vdrum generally designated at 4t). The drum 4G is provided at adjacent points through its periphery with a pair of apertures 41, through which extend the opposite ends of the cord or wire, these latter being secured interiorly of the drum as by bolted clamps 42, best shown by Fig. 5. From this arrangement it will appear that the length of band 35-36 trained over pulley 34, will be disposed in wound or Wrapped relation in spirally grooved seats therefor, indicated at 43 on the periphery of the drum 40. It will also be noted as a preference that the upper pass 36 of the flexible band is kept substantially in a horizontal plane parallel tothe plane of the table top, in order that a constant .vertical spacing be maintained between the pass 36 and the straight edge member. Y
Anchorage of the graduated strip element forming the straight edge 20, to the traversing mechanism, is provided for by a bolted clamp 45 (Figs. 2 and 4) carried by a downward arm of an L-shaped bracket 45, bolted through a spacer member 47 to the outer edge of member 2), as will best appear in Fig. 4, the same arrangement obtaining at the opposite end of member 20 for connection to the companion traversing unit.
Adequate and substantiallyV constant tension of the flexible band 35-36 is assured by interposition of a small tension spring 56, shown in the lower pass 35`of the band, major tension adjustments being made by extension or retraction of length ofthe frame structure, as by relativeV displacement of the sections 25 and 27 through slot 3Q and screw 32.
1t is, asbriefly noted, highly advisable to assure, in-
cident to traversal of the straight edgeV member 2t), a
preeisely equal displacement of both ends thereof, in order to assure parallelism of member 20 with the members and 13, under all conditions. For this purpose, there is provided a positive operating connection between the paired winding drums 40 through the agency of a sectional shaft, s'o formed as to enable attachment of the several items of apparatus described, to work tables of a variety of dimensions. For low cost and convenience of length adjustment, thisV drum shaft includes, by way of example, a solid shaft 51 provided with a plurality of Vdiametral apertures 52, serving selectively/to receive a fastened screw 53, diametrally` bridging spaced openings therefor in a hollow shaft section 54. t Onejor a plurality of the sections 54 may be provided, it being understood that each of the traversing units includes one of the solid shaft sections 51, so that through the selection of various openings 52 and the selection of one or more of the hollowk shaft sections 54, a substantial range of overall shaft bearing arm 26 earlier described and is xed to a drum 46 by a key 49.
The arrangement described presupposes a traversing movement of the straight edge member 20 by direct manipulation of such member for which purpose, if desired, member 2t) may be provided with handle or knob elements (not shown). Merely to illustrate the versatility and adaptability of the described arrangement, there is shown (Figs. 1 and 7) a T square TS employed with the member 2t? and provided with an offset or step portion TSS, which extends from the head of the T square a distance substantially equal to the width of the member 20.v
It will now have appeared that as the member 20 is traversed in a given direction, both ends thereof will be exactly equally displaced irrespective of the zone in which the straight edge is grasped. As the member Z0 is moved, it will appear that an increasing length of one of the passes 35--36 is Wrapped on the winding drum 49, while an equal length of the opposite pass is unwound therefrom. Slippage of the cord, band or Wire is effectively precluded by the extent of wrapped length of band or cord engaging the grooved seat on the drum, and by the even tension provided by proper frame adjustment, and the maintenance of tension by spring 50. Repeated experimental usage of the present arrangement Yunder actual metal shop conditions, indicates that under all conditions of actual shop practice, and even under moderate intentional abuse, a barely discernible difference in displacement of the two ends of the straight edge element. Even when the member 20 is of a length of 10 feet, no departure from parallelism has been observed in excess of .010l inch.
The purchase of sheet metal layout equipment, as for straight edge scoring, etc., at the present time usually entails a minimum cost of $1,000.00-$l,200.00, including a specially constructed table. It is contemplated that, based on experience to date, a table attachment kit adapted for mounting on a conventional table top, may be produced and sold to the user within a current price range of $150.00-S200-00. Such a kit would consist of atleast a pair'of the traversing units, one of which is shown by Fig. 2; a straight edge or scoring guide elementV such as 20, and an adjustable-length shaft such as 51'-54. Op-v tionally, but in most cases desirable, particularly for sheet metal layout work, are the additional, normally fixed, graduated work-abutment strips, such as 10, 13, 15 and 16. This equipment, light in weight and low in cost, is not critical in requiring a table of Vany' certain dimensions, since different table lengths may be accommodated by adapting thereto the length of the sectional shaft 51-54, While moderate differences in table widths may be met by length adjustment of the frame elements and bands of the traversing units. 25-27, such unit may be formed of a greater number of sections within practical limits, whereby production may be virtually standardized to meet the usual requirements of small sheet metal working shops.
Adaptation of the straight-edge and abutment members to tables of different sizes, is facilitated by deeply Y indenting the parts 10, 13, 15, 16-iand 20 along trans-l verse lines which may be certain of the graduation lines, thereby conducing to ease of severance of the unwanted length of the member, and quickly adapting ,same to Vthe specific table at the place of usage.
It will now have appeared that the arrangement Y described by way of example, will serve fully'to realize lengths may be provided.l VEach of the solid shafts 51 Vat', Y
the ends of the sectiond shaft'st'ructure is operatively journalled'in a sleeve bearing 55, carried Vby the depending the several objects hereinabove expressed, ,and others implied from manner and scope of usage. Although the exemplary structure has been referred to in detail,V the detail of the description should be understood in an instructive rather than in any limiting sense, numerous variants being possible within the fair scope of the claims hereunto appended.v Y Y v .Y
I claim as my invention: Y j A i 1. A work table for sheet metal, including a substan- In the sectional frame structuretially rectangular table vtop element, a straight-edge member movable between front and back margins of the table, a pair of straight-edge traversing units, one located along each side margin of the table, each said traversing unit comprising a exible band, pulleys over which the band operates and a connection between the band and the adjacent end of the straight edge, the pulley at one end of each of the traversing'units being of a width to receive a substantial length of the flexible band wound thereon, and a shaft structure formed of a plurality of sections susceptible of connection in variably overlapping relation to enable an adjustment in overall length of the shaft structure, the sectional shaft structure being rotatively supported along the back margin of the table, and operatively secured to the winding pulleys of the straightedge traversing units, whereby to compel identical rotation of the winding pulleys incident to traversal of the straight edge member.
2. A work table for marking or scoring flat elements of sheet metal or the like, and including a substantially rectangular planar table top serving as a work surface, a straight-edge member movable between front and back margins of the table, a traversing unit at each side of the table, each of said traversing units comprising a exible band, pulleys over which the band is trained and a connection between the band and an end portion of the straight edge member, each said traversing unit further including a rigid frame member by which the pulleys and the band are supported, said frame member being attached to the table along one side of the table top, said frame member being formed of a plurality of sections adjustable toward and from each other whereby to vary the length of the frame member to adapt same to tables of differing widths, and further adapted to enable a tension adjustment of the exible element, and a shaft rotatably supported along the rear margin of the table and serving operatively to interconnect a pair of the pulleys of the companion traversing units whereby to compel identical motion thereof incident to traversal of the straight-edge member.
3. A work table for marking or scoring tlat elements of sheet metal or the like, and including a substantially rectangular planar table top serving as a work surface, a straight-edge member movable between front and back margins of the table, a traversing unit at each side of the table, each of said traversing units comprising a flexible band and pulleys over which the band is trained, a connection between the band and an end portion of the straight edge, each said traversing unit further including a rigid frame member by which the pulleys and the band are supported, said frame member being formed of a plurality of sections adjustable to permit extension of the frame member to adapt same to tables of diiering widths, and further adapted to enable adjustment of the flexible element for maintenance of tension of the flexible element, and a shaft rotatably supported along the rear margin of the table and serving operatively to interconnect a pair of the pulleys of the traversing units whereby to compel identical actuation thereof incident to traversal of the straight edge, said shaft being formed of a plurality of sections arranged in variably overlapping relation to enable adjustment of shaft length, whereby to adapt the shaft to work tables of varying length.
4. In a work table for use in marking or scoring sheet metal, a substantially rectangular, planar table top characterized by front, back and side table margins, a straight-edge element movable between the front and back margins of the table, a pair of traversing units, one extended along each side margin of the table edge, each such unit comprising a ilexible band and pulleys over which the band operates, a connection between the band and an end portion of the straight edge element, each such traversing unit further including an angle frame member by which the pulleys and the band are supported, the frame member being of sectional construction with the sections thereof adjustable to vary the length of the frame memberV to adapt same to tables of differingposableto provide for variation in shaftlengthto adaptV the shaft to work tables of dierent lengths, and 'means' for assembling the telescopically related sections to establish a predetermined length of shaft.
5. In a work table for layout of sheet materials, a rectangular table top and support therefor, the table top including front, back and side margins 4defining a rectangular work area on the top, a traversable straight edge element movable parallel to and between the front and rear margins of the table top, and characterized by indented indica forming a graduated measurement scale, a straight-edge traversing unit mounted `along each side margin of the table, each said unit including a rigid angle member forming a main section and an auxiliary metal member constituting an auxiliary section, the sections being secured together in length-adjustable relation, a grooved drum rotatively `carried by one of said sections, a pulley carried by the other of said sections, a flexible band trained over and adapted to be wound upon the drum and to operate over the pulley, a clamp engaging the band and connected to one end of the graduated straight edge element, and a sectional shaft interconnecting the -drums and extended along the rear edge of the table, the sections of the shaft being linearly adjustable to enable a variation in shaft length, and a xed metal straight edge element mounted parallel to the movable straight edge element, and being charatcerized by indented indica forming a graduated scale for measurement purposes and constituting an edge abutment for sheet stock disposed las a work piece on the table.
6. Apparatus -for attachment to a rectangular Work table to provide therewith a traversable straight edge member operable across the table in a path parallel to a table margin, said apparatus including a pair of operative units to permit traversal of the edge member, each such unit being arranged for detachable mounting along one side margin of the work table and including a frame member of angle section, a second frame member carried by the angle member, said members being provided with a slot and screw `connection to enable length adjustment of the frame to adapt the units to tables of dilering widths, a bearing arm dependingly supported from one end of the angle member, a second bearing arm dependingly supported from the second frame member to enable an adjusted spacing of the bearing arms, a winding drum characterized Iby a spiral band seat thereon and supported` by the first said bearing arm, a exible band trained in wound relation over the winding drum, a pulley rotatively carried by the second said bearing arm, the band being operatively trained over the pulley, a clamp engaging one pass of the band between the pullley and the drum, and serving to attach the band to one end of the straight edge member, and a shaft for interconnecting the winding drums of the traversing units, the shaft being extended along and parallel to a rear margin of the table, the shaft being formed of sections variably related to provide for adjustment in shaft length, the sections of the shaft being tixedly angularly assembled, whereby to Icompel and equal rotation of the winding drums, hence an equal displacement of the opposite ends of the straight edge member incident to traversal thereof over the work surface of the table.
7. Apparatus for attachment to a rectangular work table including a rigid, movable straight-edge member for parallel traversal of the table top, paired units for mounting along and parallel to opposite sides of the table, each said unit including a sectional frame, the sections of which are variably related to adjust the length of' the frame, a pair of pulleys near opposite ends of each unt,
a flexible band trained over therpulleys, and beating arms serving the pulleys for connection of same to diierent sections of therframe, and a variable-length shaft serving to interconnect Corresponding pulleys of the paired traversing units.
K References Cited in the file of this patent *UMTED' sfmTEsV PATENTS Davis V Apr. 12, 1921. Sorensen June 4, 1935 Reichart July 2, 1935 Zimmerman Sept. 6, 1938