US3507025A - Method for drilling holes in girders and splice plates - Google Patents

Description

April 21, 1970 K. s. ANKENEY 3,507,025

METHOD FOR DRILLING HOLES IN GIRDERS AND SPLICE PLATES Filed Jan. 18, 1968 3 Sheets-Sheet 1 g BYWXW 72 ,4 TTOR/VEX April 21, 1970 K. s. ANKENEY 3,507,025 METHOD FOR DRILLING HOLES I-N' GIRDERS AND SPLICE PLATES 1 Filed Jan. 18, 1968 3 Sheets-Sheet a //V VE/V 7 OP. KEITH 5. ,4/VAENE) 3M QM ,4 Tron/m! April 21, 1970 K. s. ANKENEY I 3,507,025-

METHOD FOR DRILLING HOLES IN GIRDERS AND SPLICE PLATES F'iled Jan. 18, 1968 3 Sheets-Sheet 3 IN VENTOR KEITH 5. ANKENEY ATTOP/VEX United States Patent 3,507,025 METHOD FOR DRILLING HOLES IN GIRDERS AND SPLICE PLATES Keith S. Ankeney, Clive, Iowa, assignor to Pittsburgh- Des Moines Steel Company, Des Moines, Iowa, a corporation of Pennsylvania Filed Jan. 18, 1968, Ser. No. 698,921 Int. Cl. 323p 17/00 US. Cl. 29155 4 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Field of the invention This invention relates to an improved method of initially forming accurately aligned holes in splice plates and abutting ends of beams or girders to be secured by such plates, and has particular application to the installation of bridge girders.

More particularly this invention relates to drilling holes in pre-aligned girders and splice plates and includes improved apparatus for carrying a drilling assembly and orienting the drill bits relative to the material to be drilled.

Description of the prior art In the construction of bridges, for example, girders generally comprise multiple sections secured in endwise alignment by splice plates bolted to the abutting ends of the sections. As presently practiced, such ends and the splice plates are sub-drilled or sub-punched at marked points prior to actual installation. The diameter of such sub-drilled or sub-punched holes is smaller than what their final diameter will be so that when the splice plates are positioned at installation for attachment to the girder, any matching holes in the girder or plates that do not properly register are reamed to size and registration. In actual practice, a good deal of reaming is usually necessary and are infrequently, the non-registration of the matching holes is such that after reaming, one or both of the holes will be oval or egg-shaped. When this occurs, it is usually necessary to fill the holes in whole or part by welding and re-drilling them.

It will be readily appreciated that the foregoing practice is expensive in time and labor and the primary object of the present invention is to provide an improved method and apparatus for initially drilling the holes in the girders and splice plates whereby they will be in proper registration when the girders are placed in their final position and thus eliminate the double effort of subdrilling or sub-punching and the later reaming.

SUMMARY ,7 The present invention is directed I to an improved method, and apparatus therefor, of forming, in one operation, accurately registering bolt holes in girder ends and splice plates to be secured thereto. This contemplates aligning the girders, prior to actual installation when they "ice are preferably at their fabrication site, in the exact relative position they will have when installed; clamping the splice plates in their appropriate position on the girder and then drilling the desired holes of correct sizes at designated places through both the splice plates and the girders.

Also, this invention, while employing a drill unit preferably with multiple spaced adjustable bits and of a type commercially available, includes a novel portable drill unit supporting structure which is clamped to the material being drilled and embodies means that afford lateral and vertical adjustment of the drill unit whereby the drill bits can be aligned to contact the material to be drilled at any predetermined point or points.

The advantages of the present method over current practices is that the simultaneous drilling of the girder and splice plates as outlined provide properly aligned holes ,in a single and final operation and eliminates considerable time and costs formerly required in sub-drilling or sub-punching and reaming. In addition, the supporting structure for the drill unit is clamped to the material to be drilled so that, while the drill can be selectively moved laterally and vertically, neither the supporting structure nor the material to be drilled requires moving. Such supporting structure for the drill unit is equipped with accessories such as lights, levelling devices and a fluid cooling system for the bits to enhance its efficiency.

The objects of this invention together with details of the operation outlined and the advantages of the same will be more fully described and developed in relation to the more detailed description of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view showing the drill unit supporting structure clamped to material to be drilled and ready for operation of the drill,

FIG. 2 is a front elevational view taken on the line 2-2 of FIG. 1,

FIG. 3 is an enlarged perspective View of a multiple bit drill unit or assembly used with this invention,

FIG. 4 is an enlarged perspective View of the levelling device for the clamp means securing the drill supporting structure to the material to be drilled,

FIG. 5 is an enlarged elevational view showing separate clamps securing the splice plates to the girder,

FIG. 6 is similar to FIG. 5 but showing the splice plates in a dilferent position relative to the girder, and

FIG. 7 is a longitudinal sectional view taken on the line 77 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Refering to the drawings, a girder is shown generally at 10 and includes the respective fiange and web portions 12 and 14. It will be understood that such girder 10 as seen in FIGS. 1, 5 and 6 represents the point at which two such girders are in endwise abutting engagement in the position at which such ends are to be secured by splice plates designated by the numerals 16, 18 and 20. The relationship of the abutting ends of such girders for purposes of the following disclosure, and prior to their movement to and installation at their permanent site, are carefully and accurately aligned in the exact relative position they will assume when actually installed. When this has been accomplished, the splice plates 16, 18 and 20 are secured in their splicing position by the respective C clamps 22 at opposite ends of girder flange 12 and are thus ready for the drilling of the bolt holes as will appear. The position of the splice plates for such drilling may be either as seen in FIGS. 1 and 5 where they are all on the outer side of the flange 12 or the two shorter plates 16 and 18 may be placed as seen in FIG. 6 where they are on opposite sides of the web 14. In the actual installation, the splice plates will be positioned as in FIG. 6 but for purposes of this disclosure, this is not necessarily required. The foregoing pre-alignment of the girders and clamping of the splice plates thereto in their actual position relative to final installation is believed to be a novel approach to the forming of the bolt holes in the girder and splice plates as heretofore such holes have been customarily formed by sub-punching or subdrilling as is well known. Thus, with the girders and splice plates set up as indicated, I will now describe my improved apparatus for drilling the necessary bolt holes therethrough.

With reference to FIG. 3, a drilling assembly or machine is shown at 24 and with the exception of the cooling apparatus which will be later referred to in more detail, machine 24 is of a type that is commercially available so that a detailed description of its construction is not necessary. In general, however, machine 24 is powered by an electric motor 26 (FIGS. 1 and 2) and preferably includes a plurality of spaced drill bit units 28. As is well known, the lateral spacing between units 28 may be manually adjusted within prescribed limits, a depth of cut control is provided which acts to cause retraction of the bits from the workpiece and various switch controls are provided for the general operation of the machine for which no invention is claimed. Such switch controls have been incorporated into a multiple switch control box 30 which I have arranged for convenience and will be referred to in more detail as this description proceeds.

With reference now to FIGS. 1 and 2 and as perhaps best seen in FIG. 1, there is shown a supporting frame structure designated generally by the numeral 32 which has been designed to support machine 24 and to provide, amongst other things, lateral and vertical adjustment of such machine and the drill units 28 relative to the workpiece. Structure 32 is generally an open, rectangular, box-like frame which includes the lower frame assembly 34 mounted on caster wheels 36, the upper frame assembly 38, and four cylindrical corner posts 40. On each corner post 40 there is mounted an elongated sleeve 42 which is machined so that it will easily slide up and down relative to such posts. Horizontal cylindrical rails 44 connect the several sleeves 42 so that said rails 44 and sleeves 42 define a vertical slide assembly which can be raised and lowered as will be later referred to in detail. A horizontal or lateral slide assembly is mounted to the vertical slide assembly described and this includes the sleeve 46 shown in FIG. 2 slidably mounted on the front rail 44 and a similar sleeve mounted on the like rear rail 44. Machine 24 is mounted to sleeves 46 in any suitable manner so that such machine as a unit may be moved laterally or vertically with the respective lateral and vertical slide assemblies as will appear.

The frame structure 32 thus far described, together with other operative mechanism to be described later, is a relatively heavy unit and is best moved from one general location to another by means of a crane. For this purpose, I have provided lifting lugs 48 on the upper frame assembly 38 and thus by use of a crane (not shown) attached to the lugs 48, frame unit 32 may be moved to the general location of the girder with the splice plates 16, 18 and 20 clamped thereto as described. In this position, frame 32 can be manually pushed on the casters 36 to its actual operating position as shown in FIG. 1. At this point, the frame unit 32 is clamped to the workpiece and levelled in relation thereto by means of a clamping assembly designated generally by the numeral 50 as seen in FIG. 1 and as better illustrated in the enlarged perspective of FIG. 4. There are two clamping asesmblies 50 in vertical spaced relationships at each front corner of frame 32 as shown and which will be referred to as the upper or lower assembly. Such assemblies 50 are slidably mounted by means of respective sleeves 52 to the respective posts 54 which are supported adjacent and to the outer side of the front corner post 40 by the repsective upper and lower brackets 56 attached to frame 32 as seen in FIG. 2. Sleeve 52 is vertically adjustable on post 54 by means of the screw 58 as best seen in FIG. 4 and attached to sleeve 52 in another sleeve 60 through which there is horizontally slidable the hollow arm 62. The forward end of such arm 62, being the left end as viewed in FIG. 4, is provided with a pair of pivotally mounted C clamps 64 and the respective upper and lower clamp assemblies 50 on each post 54 have the clamps 64 arranged for movement as best seen in FIG. 1. The slidable movement of arm 62 relative to sleeve 40 is controlled by the screw 66. A tightening screw 68 extends through the arm 62 as seen in FIG. 4 and can be rotated into engagement with the workpiece as seen in FIG. 1.

With the four clamp assemblies constructed and arranged as described, the clamps 64 will be in their dotted line position seen in FIG. 1 when frame 32 is initially oriented relative to the workpiece. The clamps 64 on the upper assembly 50 are turned over the top of girder 10 and clamps 64 on the lower clamp assembly 50 are turned up to similarly engage the girder. In turning up the lower clamps 64, a bolt 70 is inserted into arm 62 to hold such lower clamps from falling downwardly. It will be understood that clamp assemblies 50 will be adjusted to assure that posts 54 are paralel to the workpiece so that the drill units 28 will be perpendicular thereto. The screws 68 may be tightened against the workpiece although this is not necessarily required since once the drills contact the workpiece, the clamp 64 will be drawn tightly against the workpiece by the operation of machine 24.

With frame 32 thus clamped and aligned relative to the workpiece, the drill units 28 must be aligned for actual drilling and it will be understood that the workpiece will be suitably center punched and/or marked in any well known manner to indicate the exact point of contact for the drill point. The final alignment of units 28 is accomplished by means of the lateral and vertical slide assemblies on which machine 24 is mounted and which I will now refer to in more detail.

In the operation of the vertical and lateral slide assemblies, certain electrical button switches are utilized and, for convenience, these have been assembled in the single control box 30, previously referred to. Details of the wiring associated with control box 30 have not been shown since they form no part of this invention and it is believed that by indicating the relationship of identified switches with identified parts, the necessary wiring would be within the skill of anyone familiar with such work.

To raise and lower the vertical slide assembly, I have used a pair of vertically disposed rotating screws 72 disposed respectively at each side of frame 32 so as to extend between the lower frame assembly 34 and the upper frame assembly 38 as illustrated in FIG. 1. Such screws 72 rotate in respective large nuts 74 which are welded to the adjacent side rails 44 forming part of the vertical slide assembly. The upper ends of screw 72 are operatively connected to the gear reducing unit 76 located on the upper frame assembly 38. Such gear reducer is connected for operation to shaft 78 which is supported in mounts 80 and connects to motor 82 through coupling 84. As seen in FIG. 2, each screw 72 is provided with a separate gear box and corresponding connections to the motor 82. For the adjustment of the vertical slide assembly, control button 86 is held depressed for an upward movement of the slide assembly and button 88 is held depressed for a downward adjustment. Both buttons 86 and 88 are electrically connected to motor 82 in a well known manner for rotating screws 72. A magnetic brake means 90 is provided on shaft 78 intermediate the motor 82 and one of the gear reducing units 76 so that said brake is activated to stop the movement of a vertical slide assembly when either of the buttons 86 or 88 are released.

For purpose of moving the lateral slide assembly in two respective opposite directions, I have provided the steel rack 92 which is welded to a square pipe 94 that in turn is welded to the two rear sleeves 42. An electric motor 96, suitably mounted to the lateral slide assembly (FIG. 1) is connected through coupling 98 and shaft 100 to the pinion gear 102 which is engageable with the rack 92. Shaft 100 is attached to the lateral and vertical slide assemblies by means of mounts 104. Thus, by the actuation of button 106, the lateral slide assembly will move in one direction and by actuation of button 108, such assembly will move in the reverse direction. It will thus be appreciated from the description so far that the drilling machine 24 can be quickly and accurately, vertically and laterally adjusted to orient the point of the drill bit with any designated portion of the workpiece.

I have added to the machine assembly 24 a cooling system especially adapted to cool the drill units 28 as they drill into the steel plates represented by the girder 12 and the splice plates 16, 18 and 20. This cooling system is designed to re-circulate a suitable coolant so that no separate supply for a coolant is required. A trough 110 is secured as by welding to a slide member 112 that in turn is slidably secured in any suitable manner to the frame 32 so that it can be moved outwardly from the frame as required to be directly under the workpiece. An extension 11-4may be formed on the trough, if desired. Trough 110 serves both as a collecting trough for the coolant discharged on the drill bits as will later appear and also as a reservoir for the collected coolant, and for the purpose of preventing metal drill shavings from falling into the reservoir portion of the trough, a filtering element 116 is provided on the top of the trough. A pump 118 delivers the coolant from the trough through a supply line 120 which is connected to a manifold 122 having a respective hose and nozzle 124 for each of the drill bits and a manually operated valve means 126 is interposed in the flow line 120. Nozzles 124 are positioned to direct a fiow of coolant on 'the drill bit during operation of drills 28 and the op eration of pump 118 is controlled by the button switch 128.

For convenience, I have provided the lights 130 which are mounted to the upper frame assembly 38 and which are oriented to illuminate the workpiece making for an easier alignment of the drills with the center punch marks on the girder flange.

With the frame 32 clamped to the workpiece and the drill units 28 properly aligned relative to the workpiece as described, the drilling machine 24 is operated in its customary manner. While no invention is claimed in machine 24 as indicated above, its general operation is as follows. The main drill motor 26 is activated by pressing button 132, turning the switch 134 to what is designated as the jog position and pressing button 136 which starts the drill bit units 28 in motion. As soon as such bits are rotating, button 136 is released and switch 134 is turned to the run position. At this point, button 136 is again pressed and machine 24 will then be in operation. As indicated previously, machine 24 contains a depth of cut control means and when such depth of cut has been reached, suitable mechanism on machine 24 not material to the present invention, will cause the drill units 28' to be retracted fromthe workpiece. In general, this is accomplished by locating sleeve 138 as desired on shaft 142 and tightening screw 140 and as shaft 142 moves forwardly, sleeve 138 acts on switch 144 to reverse the forward direction of movement of machine 24. Also, it should be pointed out that in the adjustment of the vertical slide assembly as described previously, switches 146 and 148 at the respective upper and lower rear portion of frame 6 structure 32 (FIG. I) serve to shut off motor 82 when the slide assembly contacts such switches at its limit of travel. As soon as the desired number of holes have been drilled in the workpiece, frame 32 is released from the workpiece and can be moved by a crane to another operating location.

It will thus be appreciated from the foregoing that registering holes will be drilled in one operation through the girder flanges and the splice plates and because of the fact that the position of such girder and splice plates at the time of drilling is identical with the position, so far as the drill holes are concerned, they will be encountered in the actual installation, there is no necessity at the time of the actual installation for reaming and/or welding and re-drilling any holes in the parts to be bolted together.

Thus, from the foregoing it is thought a full understanding of this new method and the construction operation of the apparatus used therewith will be had and the advantages of the same will be appreciated.

It is pointed out that while the drilling machine 24 is illustrated in the drawings for purposes of this disclosure with the bits 28 oriented on a horizontal plane, theremaybe times because of the position of the material to be drilled, that machine 24 will be suitably mounted on structure 32 so that the bits 28 are disposed in a vertical plane. Such an arrangement, however, will in no way affect the construction and operation of this invention as described above.

It will be understood that the phraseology employed herein; is for the purpose of description and not for limitation and that modifications and changes can be made within the scope of what is claimed, without departing from the spirit and purpose thereof.

I claim:

1. A method for forming bolt holes in birders and in splice plates to be attached thereto which includes:

aligning the girders end to end prior to actual installation but in their actual relative position for final installation,

temporarily aflixing the splice plates to said girder ends in their actual relative position for final installation,

drilling the desired holes through said splice plates and girder ends, and

removing said splice plates from said girders.

2. A method as defined in claim 1 which is performed at a point remote from the actual site of installation.

3. A method as defined in claim 1 including the drilling of said holes to the correct size required for the final attachment of said splice plates to said girder ends. 4. A method as defined in claim 1 including: temporarily securing a drilling machine to said girder ends, aligning said machine relative to the point of drilling, and

disengaging said machine from said girder ends after the desired holes are drilled.

References Cited UNITED STATES PATENTS 480,040 8/1892 Saylor 77-6 3,249,954 5/1966 Franckowiak 7755 XR 2,995,826 8/1961 Brault. 5 2,669,135 2/ 1954 Moore 775 1,715,694 6/1929 Coddington 29155 FRANCIS S. HUSAR, Primary Examiner US. 01. X.R.

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