US3154979A

US3154979A - Metal working machine

Info

Publication number: US3154979A
Application number: US664432A
Authority: US
Inventors: Thayer S Crispin
Original assignee: Douglas Aircraft Co Inc
Current assignee: Douglas Aircraft Co Inc
Priority date: 1957-06-07
Filing date: 1957-06-07
Publication date: 1964-11-03
Anticipated expiration: 1981-11-03

Description

Nov. 3, 1964 T. s. CRISPIN 3,15 ,9

METAL WORKING MACHINE Filed June 7, 1957 10 Sheets-Sheet 1 Nov. 3, 1964 'r. s. CRISPIN. 4,

' METAL WORKING MACHINE Filed June 7, 1957 10 h s-Sheet 2 IN VEN TOR.

7344762 5 CF/sP/A I Z3- BY 'Armzzvs/ Nov. 3, 1964 1'. s. CRISPIN METAL WORKING MACHINE Y 10 Sheets-Sheet 3 Filed June 7, 1957 INVENTOR.

10 Sheets-Sheet 6 INVENTOR.

Nov. 3, 1964 T. s. CRlSPlN METAL WORKING MACHINE Filed June 7, 1957 Nov. 3, 1964 T. s. CRISPIN 3,154,979

METAL WORKING MACHINE Filed June 7, 1957 10 Sheets-Sheet '7 INVENTOR.

dr ve/v45 Nov. 3, 1964 T. s. CRISPIN 7 IN V E R rm 5 Case/N T. 5. CRISPIN METAL WORKING MACHINE Nov. 3, 1964 10 Sheets-Sheet 9 Filed June 7, 1957 INVENTOR. Anne 5. (k/SPl/V Nov. 3, 1964 T. s. CRISPIN METAL woaxme MACHINE l0 Sheets-Sheet 10 Filed June 7, 1957 INVENTOR. 77'Hfi j6e/sP/A/ EEi 2 United States Patent 3,154,??? METAL WORKUQG MAQI Thayer S. Crispin, Malibu, Cahf, assignor to Douglas Aircrfit Company, Inc., Santa Monica, alif. Filed June 7, 1957, Ser. No. 664,432 4 Claims. (Cl. 78- 39) This invention relates to machines which are adaptable for riveting, drilling, dimpling, countersinking and like operations either singularly or in various combinations and more particularly to an assembly of this class which is capable of functioning satisfactorily under relatively high operating loads and which can be utilized effectively in conjunction with workpieces of relatively large expanse or size.

The machine of the present invention comprises in general an assembly wherein the mechanism effecting a given operation is carried by a relatively light yoke memher which can be manually positioned accurately, and wherein the yoke is carried by a relatively heavy member capable of withstanding high working loads.

Progress in industry, and particularly in the aviation industry, creatin new designs and innovations in structures, has caused the manufacturing agencies to seek faster and more eilicient fastening machines and methods to facilitate the production of quality components at reduced coast. There are, however, rigid specifications, and this is especially true in the aircraft industry, which dictate the basic rules for the design of new machines, fasteners and processes, in order to meet the requirements of the engineering design and the customer. The trend for the past several years has been toward the use of multicycling devices utilizing available machines controlled by electronic mechanisms and programmed tape, and such devices have achieved the first step toward producing a quality article with consistent results.

As aircraft design requirements changed from thin skins and stringers to heavier plate skins and extruded or milled stringers, new fasteners were specified for securing these components into a completely sealed integral portion of a Wing to produce what is commonly termed an integral fuel tank. The introduction of the Slug fastener (a non-pre-headed rivet), placed in a pro-drilled and countersunk hole, upset at both ends and shaved in one position stop was a great advancement in machine riveting. Recently, however, heavier, high-performance transport airplanes have presented a particular challenge, for structures havin hi her loads and stresses must be made compatible with integral fuel tanks. These tanks are common on modern transport aircraft and such structures must be produced with leakproof riveted joints, conforming to rigid and exacting requirements.

Modern large airplane designs call for panels which are in some instances ten feet by fifty feet, fabricated from /4. inch thick aluminum skins fastened to stringers and having approximately 8500 fasteners, all of which must be of pert" ct quality. Various machines and methods have heretofore been used to perform operations such as riveting, drilling, countersinking, dimpling and the like. In the case of workpieces of relatively small size, and of operations not requiring high operating loads and pressures, the equipment previously utilized has proven adequate. However, in the case of the fabrication of arge workpieces such as wing skins, fuselage panels and spar assemblies, presently used machines and methods are inadequate. The large, heavy sections of material are extremely difficult to handle and the throat depths of present open throat yokes are not capable of handling skins or panels of extreme width.

For the sake of convenience, the riveting operation will be considered the typical use of the present invention. However, as previously described, it should be understood that any of the operations normally concerned with the fastening of materials together can be utilized in conjunction with the present assembly.

Gne system currently in operation utilizes stationary open throat yoke machines of various types all requiring the work to be carried rivet by rivet through the machines. This, of course, necessitates a setting aside of floor space totaling at least twice that of the material being worked on, for the work is positioned on one side of the machine and then moved through the machine during the operating cycle to assume a similar position on the opposite side. This utilization of extensive premium assembly floor space is a major disadvantage inherent in such operating techniques and was a contributing cause of the research leading to the present invention.

The previous approach to the problem also requires massive stationary machines in order to overcome the problem of deflection in deep throated yokes because of the squeezing pressures and large work-pieces involved in present day operations. Another undesirable characteristic inherent in the current system is the difiicult problem of moving large heavy assemblies accurately through a stationary machine as each single or plural operation sequence is performed. This problem of moving the mass of the Work, plus the workholder, accurately a predetermined linear increment has brought about the development of automatically controlled machines. These machines utilize complicated and expensive positioning equipment to index each stop position and operation, such equipment usually entailing considerable maintenance trouble and expense.

One known installation employs a multicycling machine with handling equipment which must move, stop and position accurately over 7 /2 tons of components throughout the entire sequence. The weight is caused by the necessity of moving the material to be worked upon, the work-table carrying the material, holding fixtures, and various related equipment.

A machine has also been heretofore proposed which would permit the workpiece to remain stationary while the machine moved relative to the workpiece. Rather than eliminating the existing deficiencies, the suggestion introduces additional problems, for in such an arrangemerit a piece of equipment, weighing more than the workpiece, worktable, and various holding fixtures and related equipment, must be positioned accurately rivet by rivet.

The present invention eliminates the necessity of moving the mass of the machine or the mass of the workpiece rivet by rivet, accurately. The problem of yoke deflection has also been eliminated by separating the riveting mechanism from the load-carrying members. By eliminating the necessity of moving the work to the machine and by allowing the main body of the machine to be moved approximately in position to the workpiece, the problem of excess utilization of premium floor space has been alleviated.

The present invention is essentially a fabricator and is an improvement in the approach used to mount and operate various working mechanisms'such as riveting equipment, dimpling equipment and more complicated full-cycling equipment used in drill-countersinking, rivet inserting, bucking, and shaving. It is a large tooling fimure designed to be easily positioned to the work for the general purpose of completing the fastening process of drilling, riveting and shaving in fabricating large aircraft wing skins, fuselage panels, and spar assemblies.

The machine comprises a generally rectangular, relatively heavy, outer frame, capable of withstanding high working stresses, and a relatively light C-shaped yoke carried by the outer frame and movable with respect to it. Mobility of the machine is provided by supporting Y the outer. frame on non-swivel casters connected to suit-.

3 able driving means controlled by the operator. The tooling mechanism needed to perform a given fastening operation is mounted on the yoke which is provided with a pressure pad and a pressure foot to transmit working loads directly to the outer frame.

To use the machine, the outer frame is first positioned adjacent a selected work area by the operator. The tooling yoke, carried by the outer frame, is then accurately positioned for a single or plural operational sequence within that area. Mounting the working mechanism on the light weight yoke greatly minimizes the inertia problem of indexing a large mass a linear increment. The outer frame takes damping and riveting thrusts and is capable of being stressed in excess of ten tons. Deflection between upper and lower tooling is virtually eliminated as a factor in quality control.

Additional design advantages include the ability of the machine to fabricate a scatter pattern, including curved or angled stringers and access openings. By adding a sensing ring and leveling jacks, contoured panels, including fuselage assemblies, can be fabricated to close tolerances.

On long flat panels and spar assemblies, several units can operate simultaneously. Extra yokes can be tooled for specific requirements, and switched in a few minutes to minimize production down-time for tooling changes and maintenance. Installation is simple and inexpensive with no sub-floor work necessary. Relocation of the equipment is unique'for it can be accomplished by driving the unit to a new location under its own power.

Yoke location is accomplished manually to plus or minus .010 inch, using conventional methods to establish hole positions. Normally a cycle is automatic, except for relocating, which is approximately 10% of the operating cycle although automatic control of yoke and outer frame is possible, thus making the entire operation completely automatic.

Other features and advantages of the present invention will be apparent from the following description taken in connection with the accompanying drawings in which:

FIGURE 1 is a perspective view of the machine of the present invention with portions broken away to more clearly illustrate certain details;

FIGURE 2 is schematic showing of the air motor and screw jacks, respectively, used to raise and lower the entire machine placed in their proper positions in the lower bed support and end beams, respectively, of the outer frame member;

FIGURE 3 is a fragmentary elevation view partly in section showing the details of one of the screw jacks of FIGURE 2 positioned in an end beam;

FIGURE 4 is a detail fragmentary sectional elevation view showing a portion of the driving mechanism of the machine of FIGURE 1;

FEGURE 5 is a detail fragmentary sectional view taken along the line 55 of FIGURE 1 showing the mounting assemblies for the yoke within the outer frame;

FIGURE 6 is an enlarged fragmentary elevation view showing in greater detail the tooling mechanism mounted on the machine of FlGURE 1;

FIGURE 7 is a schematic showing of the air and hydraulic circuits used to actuate the tooling accessories shown in FIGURE 6;

FIGURE 8 is a view similar to FIGURE 6 showing an alternative tooling mechanism which can be mounted on the machine of FIGURE 1;

FIGURE 9 is a view similar to FIGURES 6 and 8 showing another tooling mechanism which can be utilized in conjunction with the machine of FIGURE 1;

FIGURE 10 is a perspective view of a modified form of the machine of the present invention;

FIGURE 11 is a perspective view of the machine of the present invention with a workpiece positioned in the throat of the yoke;

FIGURES 12 to 14 are perspective views showing how the yoke of the embodiment shown in FIGURE 10 can be changed from one side of the outer frame to the other.

FIGURE 15 is a fragmentary perspective view of the machine of the present invention showing the procedure and equipment used to remove or install the yoke.

One embodiment of the machine of the present invention, referring now to the drawings and more particularly to FIGURE 1 thereof, consists of a stressed frame housing 12 containing a non-stressed, lightweight yoke 13. The outer frame 12 is constructed as a monocoque structure consisting of two

end beams

14 and 15, respectively, to which are attached by welding or other suitable fastening means two pairs of end posts 17, 18 and 19, 20, respectively. Supported on

end beams

14 and 15 and positioned between and suitably fastened to each pair, respectively, of end posts 17, 18 and 19, 20 is lower bed support 22. Upper bed support 23 is placed in spaced apart parallel relationship with lower bed support 22 and is also suitably attached to end posts 17, 18 and 1%, 2%), respectively. The outer frame assembly 12 must be capable of giving maximum rigidity and support for all fastening operations against a working load in excess of 20,000 pounds. To increase stability of the external frame member 12, four box gussets, each designated by the numeral 24, are afiixed to the end beams and the end posts at appropriate points.

As illustrated more clearly in FIGURE 5, secured by welding or otherwise suitably fastened to top face 25 of lower bed support 22, are live elongate strips, each designated by the numeral 27, preferably of hot rolled mild steel, extending the full length of the face 25. If welded, the connection need not be continuous so long as each strip 2'7 is made secure. Five similar strips, each designated by the numeral 28, are also securely attached to the bottom face 29 of upper bed support 23.

As shown in both FIGURES 1 and 5, upper and

lower bed plates

32 and 33, respectively, preferably of hardened steel plate to prevent Brinelling, are attached to the

elongate strips

27 and 28, respectively, by socket headed cap screws 34.

Referring again particularly to FIGURE 1, it will be seen that outer frame 12 is carried on a three point support consisting of two heavy duty, non-swivel, grooved casters, each designated by the numeral 35, and a third caster 37, similar except for the absence of grooving. Two Outriggers, each designated by the numeral 38, are placed at opposite ends of end beam 15 adjacent the caster 37 to prevent any twist in the frame. The entire unit is mounted upon tracks consisting of two elongate steel plates 39 and 4t) fastened throughout their lengths to studs 42 embedded in cement grouting 43. One track may be substantially flat or, as shown on 44, may contain a center depression to assure stability of the unit. To accommodate grooved casters 35, an inverted angle iron 45 is shown tack welded at approximately six inch intervals to steel plate 46.

To allow for work level adjustment vertical movement of the entire machine is necessary. This is provided, referring now to FIGURE 2, by two screw jacks, each designated by the numeral 47, properly connected to the two grooved supporting casters 35 and a third'screw jack 4% connected to non-grooved supporting caster 37. As shown more clearly in FIGURE 3, the casters are suitably attached at 49 to jack guide 5% which in turn is connected to the lower extremity 52 of one of the screw jacks 47. The power source, referring now to FIGURE 2, which actuates the jacks consists of an air motor schematically shown at 53 positioned in lower bed support 22 and connected directly to jack 4% and to jacks 47 through miter gear box 54. To prevent possible rocking or twisting of the outer frame all three jacks are connected to the same power source. 7

The two Outriggers 38, referring now to FIGURE 1,

are held in firm contact with'rail 39 by air cylinders 55,

55 connected to line pressure. When the screw jacks are actuated for raising or lowering the outer frame, the air cylinders permit the outrigger casters 38 to extend or retract accordingly. It should be understood that the three main supports for the outer frame are the casters 35, and 37 and the addition of the

outriggers

38, 38 is to increase the stability of the machine. The cylinders 55, in addition to permitting vertical adjustment, maintain the outriggers at all times in firm contact with the rail 39 regardless of the particular height at which the machine is set.

Referring now particularly to FIGURES 1, 2 and 4, the entire unit is propelled by a second air motor 57, positioned in lower bed support 22, transferring power to friction-

drive wheels

58, 58 through a common shaft 59.

Wheels

53, 58 drive against the rails 39 and 40, respectively, each wheel being mounted within a drive wheel frame 61 and connected by a chain and sprocket drive 62 to the drive motor 57. Two air cylinders, each designated by the numeral 63, one connected to each of the two wheel frames 69, are provided to compensate for vertical movement of the entire assembly. The traversing speed of the machine is adjustable up to thirty feet a minute in either direction, and is controlled by left and right hand buttons 64 located at the end of extension line 65 connected to upper bed support 23 at 67. Control buttons 68, also connected to the upper bed support 23, through the extension line 71, are provided to actuate the screw jacks to raise or lower the entire assembly when work level adjustment is desired.

The top beam 23 of the outer frame 12 contains a large reservoir 69 for storage of air and includes a check valve 70 to prevent unloading of the tank 69 in case of input line failure. As the chief external source of power to the unit is air pressure, the reservoir insures constant performance if plant pressure should fluctuate.

Referring now to FIGURES 1 and 5, operator carriage frames 72 and 73, respectively, are suspended in guide tracks 74 and 75, respectively, attached to opposite outside faces 77 and 78, respectively, of upper bed support 23.

Frames

72 and 73 can be constructed of any suitable material although applicant presently prefers seamless steel tubing. Each carriage frame is provided with rollers 79, riding in the appropriate guide track to form a trolley assembly thus permitting the

carriages

72 and 73 to be easily moved to any point along the upper bed support 23. Each carriage frame is constructed with a base platform 80 and is adjustable in a vertical direction by means of the pin and hole connections 82. To support the operator a scaffold 83 is suspended between the two base plates 80.

Positioned within the outer housing 12, referring now to FIGURES 1, 5 and 6, is the unitary C-shaped frame 13 with an upper arm 85 and a lower arm 87 defining a work receiving throat 88. The yoke or inner frame member 13 is preferably made of such light weight metal as aluminum and is held within the outer frame 12 by upper and

lower mounting assemblies

89 and 90, respectively, so as to permit rotational and longitudinal motion of the yoke within the outer frame 12. The bottom assembly 94 consists of a swivel plate 92 to which the inner frame or yoke 13 is attached by means of two support brackets 93. A combination radial thrust bearing 94 is retained by the swivel plate 92 acting in conjunction with the main plate 95 which is provided with rollers 97 facilitating longitudinal movement of the yoke 13 relative to bed plate 33. Side retainers 99, preferably rollers, are provided to prevent the main plate from moving laterally.

A swivel pivot post 1.02 holds the two plate members 92 and together. I

The upper mounting assembly 89 is similar to lower mounting assembly 9%. Yoke 13 is attached by two support brackets 1t4 to upper swivel plate 195 which, cooperating With the upper main plate 106, defines a raceway for radial thrust bearing 167. Upper swivel pivot 6 post 108 prevents disengagement of plate members and 166. Main rollers 1119, and side retainers 110, respectively, are again provided to permit longitudinal, and to prevent lateral, motion, respectively, of the main plate 106 and yoke assembly 13 relative to upper bed plate 32.

The mechanism installed on the embodiment of FIG- URE lis shown in detail in FIGURE 6 and consists of a squeeze vibrator with a shaving unit which follows immediately after the rivet is upset. Other full cycle attachments capable of installation on the basic machine are depicted in FIGURES 8 and 9 and will be more fully discussed hereinafter.

Referring now to FIGURE 6, work receiving throat 88 of yoke 13 is bounded on opposite sides by upper and

lower ram assemblies

112 and 113, respectively, attached to upper and

lower arms

85 and 87, respectively. The lower assembly 113 comprises a rivet set 114 mounted on piston 115 which in turn contains a rivet gun 117 capable of vertical reciprocatory movement. The piston 115 is slidably retained within a cylinder block, not shown, which is mounted within the lower arm 87 of the yoke. The piston 115 is capable of vertical movement within the block and is shown in FIGURE 6 in partially extended position. Since the rivet gun 117 may be any of the well-known makes of pneumatic vibrators, such as the Cleco G. B. Rivet Gun made by the Cleveland Pneumatic Tool Company, it is not shown here in detail and will not be described in detail.

Pivotally attached at 119 to the lower arm 87 of the yoke 13 is the shaver assembly 120. The upper portion of the assembly 120 comprises a cutter mounted upon the upper end of piston 84 slidably mounted in housing 122. Surrounding the cutter is a standard rivet shaver skirt 123.

Attached to upper arm 85 is control handle 124 containing control buttons 125. For the purposes of using the mechanism shown in FIGURES 1 and 6, three buttons marked start top, start bottom, and return top are provided. Their operation will be more fully described hereinafter. A cylinder block, not shown, is mounted within upper arm 85 and contains a slidably movable piston 128 to which is attached anvil 129. Working loads are transmitted to the outer frame member 12 by means of pressure pad 130 and pressure foot 132 attached to upper and

lower arms

85 and 87, respectively. An air cylinder 133 is secured to mounting plate 134 and is provided at one end with a plate and lock slide 135.

Referring now to FIGURES 6 and 7, when the button on the control handle 124 marked start top is pushed it operates bleeder valve 138 actuating a flow of air from manifold 139 through four Way valve 140 moving anvil 129 into working position on top of the rivet. When the line pressure set by regulator 142 returns to normal after positioning anvil 129 sequence valve 143 is opened allowing air to flow to air cylinder 133 moving slide lock 135 into engagement with a recess provided in piston 128 and locking anvil 12-? in position for riveting. At the same time valve 144 is opened by line pressure which allows four way valve 145 to be actuated by bleeder valve 147. Valve 144 acts as a safety valve to prevent the bottom assembly 113 from being operated until the anvil 129 is in working position and locked.

The button marked start bottom on the control handle 124 is then pushed, operating bleeder valve 147 actuating a flow of air from manifold 139 through four way valve 145 into the top of reservoir 137 forcing the oil in the reservoir to push rivet set 114 into position under the work panel. When line pressure returns to normal, set by regulator 14.3, after positioning rivet set 114, sequence valve 14.9 is opened permitting air to flow to booster 156 which increases line pressure to the proper clamping pressure. When the line pressure reaches the '7 V proper clamping pressure, pressure switch 152 opens bleeder valve-1'71 thereby opening three way valve 153 permitting air from manifold 139 to lift rivet gun 117 into position and vibrate it. Pressure switch 152 also opens bleeder valve 154- which actuates a flow of air through regulator 155 through four way valve 157 to the riveting timer 158. Timer 158 by opening bleeder valve 176 actuates four way valve 145 which forces air into the top of reservoir 159, re-positioning rivet set 114 in down position. Riveting timer 158 also actuates four way valve 164 by opening bleeder valve 131. Two three

way valves

162 and 163, respectively, are also actuated when the timer opens

bleeder valves

232 and 233, respectively. When rivet set 114 returns to the down position it opens two way valve 169 allowing air to flow through four way valve 156 to air cylinder 170 which moves shaver unit 120 into position beneath the upset rivet. The air motor actuating the cutting blades is set in operation through line 172. When shaver unit 120 is positioned under the rivet it opens three way valve 173 permitting air to push oil in reservoir 174 into the bottom of shaver unit 120 feeding the cutting blades into the upset rivet and shaving it flush with the skin. Valve 162 starts operation of shaver timer 164 which at the end of a timed stroke opens three bleeder valves 165, 167, and 168. These bleeder valves reverse the how of air through four way valves 14%, 160 and 157. When four way valve 14% is actuated by bleeder valve 165 after completion of the shaving operation the flow of air to air cylinder 133 is reversed retracting it and lifting anvil 129 into the up position. If it is desired the button marked return top can be pushed actuating four way valve 140 to retract air cylinder 133 and lift anvil 129 into the up position thus interrupting the automatic cycle. The emergency stop button also located on control handle 124 will return the upper ram, lower ram and shaver to a normal position immediately at any time during the operation of the machine.

Referring now to FIGURE 1, a coupling plug 178 is provided to connect the air and oil circuitry located in the yoke to a source of air pressure. This plug is a quick disconnect and facilitates the interchange of yokes by providing a single connection for line 179 which can be made and broken when an interchange is desired.

Referring now to FIGURE 15 consideration has been given to the vital problem of down-time which so frequently upsets manufacturing schedules. The present invention has been designed in such a manner that the working yoke 13 can be readily removed from the outer frame 12 by simply breaking the quick disconnect plug 178 and air line 179 just discussed and rolling the yoke onto dolly 186. A standby yoke can be rolled into place and made operative by re-attaching line 179. This feature will also allow yokes carrying different working mechanisms to be readily installed between the beams of the outer frame 12.

In FIGURE 8 there is shown an additional embodiment which can be utilized in conjunction with the basic machine. The tooling necessary to drill and countersink the hole, insert the rivet, vibrate or squeeze the rivet, and shave the rivet is mounted in a three station turret 182 which in turn is attached to the lower portion 183 of the yoke 184. The design of the turret is such that any one of the three stations can be used manually, or in sequence, as an automatic operation.

In the embodiment of the invention presently being described, the lower pressure foot 185 is first brought up by the action of pneumatic actuator 187 to contact the bottom of the skin not shown. The upper ram 188 is then lowered, causing upper pressure foot 189 to exert clarnp ing pressure on the parts being fastened. The work is.

held at a predetermined pressure throughout the complete cycle, thus eliminating burrs or chips, and at the same time keeping positive hole alignment for rivet insertion which is critical for fuel-tight riveting.

The drill and countersink cutter 1% is then moved up to perform the drill and countersink operation. Applicant is presently using a positive screw feed air drill with an out feed adjustment from 0 to A of an inch. The positive screw feed provides constant size of chip, close hole size control and less chance for rifting of the hole. The drill and countersink cutter 190 then retracts and the mechanism is rotated 128 degrees by pneumatic actuator 192.

The feeding of slug or headed rivets is accomplished through use of the rivet feed mechanism 1%. In operation the arm 194 swings to and from a rivet magazine according to known practice, the rivet falling into the hole 195 provided in the upper pressure foot 189. Bucking bar 197 pushes the rivet firmly through the hole and remains in contact While rivet gun 198 advances, performs the riveting operation, and retracts, and the turret then rotates The rivet shaver 199 then advances and the cutter shaves the rivet flush with the skin. The bucking bar 19'? and ram 188 retract after the shaver has retracted and the turret then returns to its initial position. The lower pressure foot drops clear of the skin. The yoke 184 is moved to the next position and the above operations are repeated.

Positive indexing of turret 132 is controlled by a shot pin stop, not shown, at 120 intervals. Timing of each station is adjustable by use of timers, not shown, adjustable from 0 to '15 seconds in one-quarter second increments. The timers can be mounted on top of the yoke within easy reach of the operator.

Controls for semi-automatic or full automatic operation are mounted on the control handle 200 fastened to upper part 201 of the yoke 134 within finger reach of the operator. Controls include everything for single or multiple operations with an emergency button which will cut olf power at any point in the automatic cycle.

In the embodiment of the invention shown in FIGURE 9 there is also shown an automatic sequence operating mechanism consisting of a three station turret 202. Here, however, the axis of rotation of the turret is horizontal rather than vertical as shown in the embodiment of FIG- URE 8. The operation is identical however except for the plane of rotation, the spindle 203 having mounted thereon a drill and countersink cutter 204, a rivet gun 205, and a rivet shaver 296.

The embodiment of the invention shown in FIGURE 10 utilizes a broken arm yoke support in place of the sliding yoke arrangement of FIGURE 1 previously described in detail.

The outer frame 207 is again designed as a monocoque structure. However, the two pairs of end posts have been replaced by single members 2&8 and 2%. Attached by welding, or other suitable fastening means, to the opposing inside faces of upper and lower bed supports 244 and 245, respectively, are upper and lower thrust plates 247 and 248, respectively. The yoke supporting mechanism consists of two arms or hinges, a primary hinge 210 attached at one end to the outer frame 207 and joined at the opposite end to a secondary hinge 211 which in turn is connected to the yoke 212. The primary hinge 210 is attached to the outer frame 207 by means of hinge pins 213 rotatably mounted within hinge pin brackets 214. Similar hinge pin connections 215 are also used to connect the secondary hinge 211 to the primary hinge 210. The yoke is provided with pressure pad 218 and pressure foot 219 to transfer the squeezing pressure to the outer frame 207.

With the double arm arrangement, it is possible to move the yoke to any position within the support area. The arms are mounted on radial and thrust type ball bearings, thus keeping joint friction to a minimum. The placement of the yoke pivot point and utilization of a two piece broken arm arrangement allows the operator maximum freedom of control in positioning the riveter over the work-piece. The yoke, of course, is designed to accommodate various types and sizes of fastening mechanisms and any of the mechanisms previously discussed can be used in conjunction with the present embodiment.

The present yoke is also preferably fabricated of aluminum alloy, thereby reducing the weight considerably and keeping operator fatigue and yoke positioning effort to a minimum. This reduction of weight permits easier transfer of the yoke from one side of the outer frame to the other. In the present embodiment retainers 217 are provided along the edges of the lower plate 248 to prevent the yoke from sliding out of the plate area.

Quick disconnect joints are provided where yoke 212 connects to the secondary hinge 211. These joints are preferably fast acting mechanical connections which do not require starting threads or hand tools to operate and are shown in FIGURE as comprising a pair of spring biased telescoping pins 249 acting in cooperation with recesses 250 provided in the secondary hinge 211.

In some instances where the particular yoke being used is not sufficiently deep throated to permit the operator to position the riveting mechanism over the far side of the workpiece, the yoke can be disconnected from the secondary hinge on one side of the outer frame and connected to a similar broken arm arrangement connected to the opposite side of the outer frame. It should be understood that such a change-over can'be accomplished in several ways. For example, the procedure previously described in connection with FIGURE can be utilized to transfer the yoke shown in the embodiment of FIG- URE 10. However, FIGURES 12, 13 and 14 show a greatly simplified method of performing this operation.

As shown, in FIGURES 12, 13 and 14, the yoke 222 is provided with two recesses or pin sockets 223 located at the top and bottom, respectively, of the yoke at approximately the center of gravity. Attached to upper and lower bed supports 224 and 225, respectively, are

brackets

227 and 228, respectively, each bracket containing a spring biased telescoping pin 229.

In FIGURE 12, yoke 222 is shown attached to end post 255 of the outer frame 257 preparatory to starting the change-over operation. The yoke 222 is first positioned relative to the outer frame 257 as depicted in FIG- URE 13 with the exception that the yoke, at this stage of the operation, would still be attached to secondary hinge 258. The spring biased telescoping pins'229 are then extended into the receiving sockets 223 provided in the yoke 222. At this point yoke 222 is pivotally supported in the outer frame 257 by means of the pins and

sockets

229 and 223, respectively. Quick disconnect joints 259 and 269, respectively, are then released, completely freeing yoke 222 from the secondary hinge 258. When the secondary hinge 258 has been moved back to a retracted position, the stage of the change-over operation is that shown in FIGURE 13.

Yoke 222 is then pivoted to the position shown in FIGURE 14 and connected to the secondary hinge 262 by inserting the spring biased telescoping pins 263 and 264, respectively, into receiving

slots

265 and 267, respectively, provided in the secondary hinge 262. Pins 229 in

brackets

227 and 228, respectively, are then retracted and the machine is ready for operation. It should be understood that, if desired, the same set of hinges can be utilized for operation of the yoke from either side of the outer frame 257, thus obviating the necessity of providing two sets of hinges. In this event the yoke is switched carrying with it the primary and

secondary hinges

268 and 258, respectively, and quick disconnect joints are provided where the primary hinge attaches to the outer frame.

As shown in FIGURE 1, the power connections 179 to the yoke 13 are flexible, extending from the center of the lower oed support 22 and are long enough to follow the full movement of the yoke. shown in FIGURES 12, 13 and' 14 similar power lines 3% are provided and are disconnected before the com- In the change-over operation mencement of the change-over sequence and a second set of power lines 392, extending from the opposite side of the lower bed support 234, are connected to the yoke when the transfer is complete. A second yoke could be added to the present embodiment of the invention or to the embodiment shown in FIGURE 1 by utilizing both power connections at the same time. Such an arrangement obviates the necessity of switching the yoke to complete the fastening operation and permits simultaneous use of both yokes thus considerably reducing the time required to complete any particular fastening sequence.

The operation of the present invention is seen more clearly by reference to FIGURE 11. The application there shown is a typical fastening procedure frequently encountered in the aircraft industry consisting of a skin panel 235 being reinforced by attaching longitudinal stringers 237. Again it should be made clear that the machine of the present invention is not limited to the operation presently being described. The present invention achieves a new degree of accuracy and ease in machine portability and is adaptable for work in fastening, dimpling and other applications where high thrust tools are an essential part of the operation. However, to simplify the disclosure of the operation of the invention, it will be described herein as a machine utilizing the attachments previously described in connection with a workpiece as shown in FIGURE 11.

The

detail parts

235 and 237 are first assembled by being placed on a suitable jig or fixture and secured together by some temporary fastening means such as tack riveting. The assembled unit is then transported to the work area of the machine and placed upon a supporting structure such as that shown in FIGURE 11 at 238 and 239.

The operator poisitioned on the scaffold 83 shown in FIGURE 1 has within easy reach the mobile control unit 64 attached to extension cord 65 which is provided to control the traverse movement of the entire machine along the rails 39 and 40. Referring still to FIGURE 1, a second mobile control unit 68, attached to extension line 71, is also provided permitting the operator toadjust the machine in a vertical direction. By use of the proper switch on the control unit 63 the vertical height of the entire machine is adjusted by actuating the air motor 53, shown in FIGURE 2, so that the workpiece is approximately at the center of the work receiving throat 240 of the yoke 242, as shown in FIGURE 11. The selection of the proper switch on unit 64 actuates air motor 57 and the machine is moved along the rails to the selected work area of the workpiece.

The yoke is then positioned manually by the use of control handle 243, referring now to FIGURE 11. If desired the yoke may utilize a power assist for longitudinal travel which is adjustable to the operators feel and automatically comes into play when the control handle is pulled or pushed. It should also be understood that complete automatic control of the machine is possible. Such complete automatic control is not feasible, however, unless a given machine application produces savings in programming which are large enough to offset increased machine and maintenance costs.

Assuming for the sake of clarification that the mechanism mounted on the machine shown in FIGURE 11 is that depicted in FIGURES l and 6, the details of which have been fully described previously, the operating procedure, when the yoke is properly positioned, is as follows. The button marked start top on the control handle 12 i is pushed bringing down the anvil 129. The button marked start bottom is then pushed advancing the rivet set 114 and causing the pneumatic vibrator to upset the rivet. "As previously described in connection with FIGURE 6, the set 114 retracts and the shaver is positioned and advanced, shaving the upset'head flush with the plate. u

When the mechanisms depicted in FIGURES 8 and 9 are utilized in conjunction with the basic machine, the

1 1 positioning and operation of the outer frame and yoke remain the same. Any deviation in the overall operation occurs subsequent to the positioning of the yoke and frame and is a result of the differing individual tools and operational sequences which characterize each of the many possible yoke attachments.

If desired two yokes can be mounted in, or attached to, the same external frame thus permitting a simultaneous operation on each side of the workpiece. However, because of the absence of yoke deflection problems, it is possible to utilize a deep throated yoke enabling the operator to reach any point on the workpiece within the work area.

It will be remembered in connection with the embodiment shown in FIGURE that, in lieu of turning the workpiece around to permit access to the entire panel width, in the case of relatively short throated yokes, it is possible to switch the yoke from one side of the outer frame to the other as previously described in connection with FIGURES 12 to 14. ment shown in FIGURE 1 this can be accomplished by simply driving the unit to a position beyond the end of the workpiece and simply reversing the position of the yoke within the outer frame. The operator can then proceed to fasten the opposite side of the panel to the stringers in the manner just previously described.

It will thus be seen that in all the embodiments of the invention herein illustrated there is provided a separation of the heavy load carrying members from the portion of the machine carrying any given mechanism. There is thus provided a basic machine which is capable of taking fastening operations such as riveting back to the operator, thus allowing engineering changes to be readily put into effect by manufacturing. The problem of incorporating such engineering changes and also master changes in the aircraft industry has sharply accentuated the need for such a machine.

Although the new preferred embodiments of the present invention have been shown and described herein, it is to be understood that the invention is not to be limited thereto, for it is susceptible to change in form and detail Within the scope of the appended claims.

I claim:

1. A metal fabricating machine comprising: a heavy frame having horizontal upper and lower load-bearing members and spaced-apart vertical end posts at each of the ends of the members; relatively light fabricating tool means encompassed by the frame and adapted to exert high working loads along a vertical axis; pressure means in alignment with said tool means for directly transmitting said loads to the frame; said tool means being adapted for insertion into and removal from the frame through either of the openings between the end posts.

2. A metal fabricating machine comprising: a generally rectangular, load-bearing, closed frame adapted to receive a Work piece; relatively light fabricating tool means encompassed by the frame, said tool means including clamping and riveting means adapted to exert high loads on a work piece; pressure means in axial alignment with said tool means for directly transmitting said loads to the frame; said frame being adapted for gross localizing movement of the machine along the length of the work piece and said tool means being adapted for fine transverse and In the case of the embodi- 12 radial movements over the work piece at any given localized position along the length of the work piece, whereby the machine can be precisely positioned for fastening operations on a stationary work piece without simultaneous movement of the frame and the tool means.

3. A riveting machine comprising: a generally rectangular, load-bearing, closed frame; a relatively light C- shaped yoke mounted within the frame and carrying clamping and riveting tool means adapted to exert high loads on a work piece; pressure means in axial alignment with the tool means for transmitting said loads directly to the frame; means for positioning the machine with respect to a stationary, generally horizontal work piece, said means including power-actuated driving means on the frame for gross localizing movement of the machine along the length of the work piece, roller and swivel means between the yoke and the frame so constructed and arranged that the yoke may be moved by manual operation horizontally in the plane of the frame and pivotally about a vertical axis, whereby the tool means can be precisely positioned over the work piece without simultaneous movement of the relatively heavy frame.

4. A machine for fabricating contoured, elongated aircraft panels, said machine comprising: an upright, substantially rectangular, closed frame adapted to absorb high axial loads without material deformation; a relatively light, C-shaped yoke mounted within the frame and carrying tool means including means for clamping the panel components together and supporting the panel, means for riveting the panel components, and means for shaving the upset rivets to produce a flush surface on the panel; said clamping and riveting tool means being adapted to exert high loads on the panel during the riveting operation; pressure means in alignment with the tool means for directly transmitting said loads to the frame; said frame being adapted for gross localizing movement of the machine along the length of the panel and said yoke being adapted for fine transverse and radial movements over the panel at any given localized position along the length of the panel, whereby the machine can be precisely posi- 'tioned for fabricating operations on the panel without simultaneous movement of the yoke and the relatively heavy frame.

References Cited in the file of this patent UNITED STATES PATENTS 746,521 Kagelmacher Dec. 8, 1903 748,823 Weaning Jan. 5, 1904 840,859 Morse Jan. 8, 1907 1,158,874 Walker Nov. 2, 1915 1,386,629 Kern Aug. 9, 1921 1,450,198 Bailey Apr. 3, 1923 1,534,018 Ames Apr. 21, 1925 1,739,152 Larsen Dec. 10, 1929 2,312,554 Jacques Mar. 2, 1943 2,456,125 Johndrew Dec. 14, 1948 2,650,521 Steinbrecker Sept. 1, 1953 2,799,187 Van Dusen July 16, 1957 2,974,548 Miller Mar. 14, 1961 FOREIGN PATENTS 441,448 Germany Mar. 4, 1927