CA1062893A - Inserting assembly for automatically inserting parallel lead electronic components into openings in a printed circuit board - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A machine for automatically inserting parallel lead type electronic components into holes in a P.C.B. The machine handles the electronic components in strip form, i.e. attached to a continuous web.
The machine includes two pairs of gripping members, the member of each pair being relatively movable to grip a respective lead wire of the leading electronic component of the strip. When the leading component is thus gripped above a pair of holes in the P.C.B., a ram is operated to engage the component, while the gripping members are being released, and force the leads into the holes. The gripping members are designed so that they do not project rearwardly of the leading component so that they cannot inter-fere with the next component on the strip. Thus, the components can be very closely spaced and their size is not as severely limited as with prior machines.

Description

The present invention relates to an inserting assembly in an automatic inserting machine for inserting electronic components such as parall01 lead type condensers into lead receiving openings of a printed cir-cuit board or the like.
In the instant specification, directions x, y and z to an elec-tronic component are defined as follows:
Direction x In a plane intersecting perpendicularly two parallel leads of the electronic component, the direction of a line formed by connecting the two intersecting points of said plane and the two parallel leads.
Direction y:
In the above-mentioned plane, the direction perpendicular to the direction x.
Direction z:
A direction perpendicular to the above-mentioned plane, i.e. a direction parallel to the above-mentioned leads of the electronic component.
In some conventional techniques for inserting electrical com-ponents into a printed circuit board only thin flat electronic components such as ceramic condensers can be accommodated.
It is an object of the present invention to obviate or mitigate this disadvantage.
It is a further object to provide an insertion assembly which prevents damage to the components due to excessive force and prevents them from being too loose due to too small a force.
A further object is to permit the increase of insertion density.
According to the present invention, there is provided in a machine for automatically inserting parallel lead type electronic components into holes in a printed circuit board, the improvement comprising inserting means for receiving an electronic component at a predetermined position and insert-ing same into an inserted position, said inserting means including -- 1 ~

(a) a frame, (b) driving means mounted on said frame, (c) first slider means driven by said driving means to move vertically, (d) second slider means movable vertically in response to the movement of said first slider means, ~e) lead holding and guiding means for holding and guiding parallel leads of said electronic component, said lead holding and guiding means being movable vertically with the movement of said second slider means, and said lead holding and guiding means including a pair of outer holding and guiding members and a pair of inner holding and guiding members, said pair of outer holding and guiding members being arranged to engage cooperatively said pair of inner holding and guiding members and thereby effect a guiding and gripping of said electronic component parallel leads therebetween at said predetermined position, and Cf) push bar means movable vertically in response to the movement of said first slider.means, said push bar means being arranged to engage said electronic component when same is guided and gripped by said lead.holding and guiding means and displace said electronic component parallel leads from said predetermined position to said inserted position under the guiding control of said lead holding and guiding means.
A conventional technique and the present invention will now be described in greater detail with reference to the accompanying drawings, in which:
Figures 1 to 7 are diagrams illustrating the states of an elec-tronic component at progressive steps in a process where electronic components on a web carrier are separated from the carrier and inserted into a printed circuit board;
Figure 8 is a front view illustrating an embodiment of an auto-matic inserting machine (used in both the conventional technique and the present invention);

Figure 9 is a perspective view illustrating an electronic compon-ent holding assembly according to a conventional technique;
Figure 10 is a sectional side view of the electronic component holding assembly shown in Figure 9;
Figure 11 is a sectional side view illustrating the inserting process in the electronic component holding assembly shown in Figure 9, wherein (a) indicates the position-setting step, (b) indicates the inserting step and Cc) indicates the electronic component-averting step;
Figure 12 is a plan view illustrating the step (c) in Figure 11;
Figures 13 to 33 illustrate one embodiment of the present inven-tion, where Figure 13 is a side view of an inserting machine;
Figure 14 is a front view of an inserting assembly;
Figure 15 is a bottom view of the inserting assembly (but with a lead holding and guiding member omitted);
Figure 16 is a side view of the inserting assembly shown in Figure 14;
Figure 17 is a sectional view of a sleeve and the surrounding portion thereof;

Figure 18 is a sectional side view of a lower slider assembly;
Figure 19, appearing on the same drawing sheet as Figure~15, is a front view of the lower slider assembly shown in Figure 18;
Figure 20, appearing on the same drawing sheet as Figure 15, is a horizontal sectional view illustrating a part of the lead holding and guiding assembly and showing the section taken along the line 20-20 in Figure 21;
Figure 21 is a view showing the section taken along the line 21-21 in Figure 20;
Figure 22 is a view showing the section taken along the line 22-22 in Figure 21;
Figure 23 is a view showing the section taken along the line 23-23 in Figure 20;
Figure 24 is a view showing the section taken along the line 24-24 in Figure 23;
Figure 25 is a view showing the section taken along the line 25-25 in Figure 23;
Figures 26 and 27 are perspective views showing top end portions of outer and inner holding and guiding members, respectively;
Figures 28, 29 and 30 are views showing the sections taken along the lines 28-28, 29-29 and 30-30, respectively, in Figure 17;
Figure 31 is a sectional view illustrating the state where the holding and guiding members are opened and showing the section taken along the line 31-31 in Figure 32;
Figure 32 is a view showing the section taken along the line 32-32 in Figure 31; and Figure 33 is a plane view showing the section taken along the line 33-33 in Figure 31;
Figures 34 to 45 illustrate another embodiment of the present invention, where Figure 34 is a front view of a lead holding and guiding assembly;
Figure 35 is a sectional front view of the lead holding and guid-ing assembly shown in Figure 34;
Figure 36 is a side view of the lead holding and guiding assembly shown in Figure 34;
Figure 37 is a sectional side view of the lead holding and guiding assembly shown in Figure 34;
Figure 38 is a view showing the section taken along the line 38-38 in Figure 36;
Figure 39 is a perspective view illustrating the top end portions of outer holding and guiding members in the lead holding and guiding assembly shown in Figure 34;

Figure 40 is a perspective view showing inner holding and guiding members of the lead holding and guiding assembly shown in Figure 34; and Figures 41 to 45 are perspective views showing the operations in this embodiment.
According to a conventional technique for inserting electronic components into a printed circuit board, an electronic component web carrier 3 as shown in Figure 1 formed by connecting many electronic components 17 in a line is wound on a reel 4, a number of such reels 4 being contained in a holding plate 2 as shown in Figure 8. l'he electronic component web carriers 3 taken out from the respective reels 4 are guided to an inserting machine 1 and cut, and the separated independent electronic components 17 are held on the top end of an inserting assembly 10 and inserted into a printed circuit board on a table assembly 11. As shown in Figures 9 and 10, the top end of the inserting assembly 10 comprises lead guide 121 and lead press 122 which are supported so that they are opened and closed to each other. The electronic component 17 is held at the portion of a lead 53 by the top end of the inserting assembly 10 and an electronic element 64 is pressed by a push bar 114 brought down from above. In performing the inserting operation, the top end of the inserting assembly 10 is brought close onto a printed circuit board 19 as shown in Fig. ll-~a~, and a lead receiving opening is located just below the lead 53 by movement of the table assembly 11 (see Fig. 81. Then, the push bar 114 is brought down and the electronic component 17 is pushed into the printed circuit board 19 as shown in Fig. ll-~b). A
part of the lead 53 projected on the back face of the printed circuit board 19 is cut out by a lead cutting and bending assembly ~not shown) operated on the side of the back face of the printed circuit board 19, and the remaining part of the lead 53 is bent by said cutting and bending assembly to fix the electronic component to the printed circuit board 19. Then, the lead guide 121 and lead press 122 are returned upwardly, but since they engage the electronic element 64 in this state, as shown in Fig. ll-~c), the lead guide 121 and lead press 122 are expanded against springs 145 and 182 and lifted upwardly in this expanded state by actions of fulcrum pins 138 and 140, levers 139 and 141, rollers 137 and 143, a fixing pin 136 and a fixing plate 142. Accordingly, the lead guide 121 and lead press 122 are prevented from hitting the electronic element 64.
The state where the lead guide 121 and lead press 122 are expanded to prevent them from hitting the electronic element 64 is illustrated in the plan view of Fig. 12. Referring to Fig. 12, leads 53 of the electronic element 64 are first pressed and held in the direction y by the lead guide 121 and lead press 122 through grooves 230 and 231. In order to release this pressing and prevent impingement of the lead guide 121 and lead press 122 against the electronic element 64, the lead guide 121 and lead press 122 are moved and opened oppositely in the direction y, whereby the state shown in Fig. 12 is attained. In order to attach a great number of electronic components at a high density on a limited area of the printed circuit board 19, it is necessary to minimize the distance m between one electronic component 17 and the adjacent electronic component 17' which has already been inserted.
However, since the lead press 122 is interposed between the adjacent elect-ronic cGmponents 17 and 17' to surround the periphery of the electronic component 17, the shape of the electronic element 64 is limited. Thus, the electronic element 64 is allowed to have only a flat shape having a very small thickness t, and for example, only ceramic condensers and the like can be inserted as the electronic element 64 and the range of applicable elements is very narrow.
As will be seen, the present invention provides an inserting assembly for electronic components in which the foregoing defects of the conventional inserting assembly are eliminated because, when the holding and guiding members are opened, the periphery of an electronic component to be inserted is not surrounded but one side in the y direction is kept free, and the size of an adjacent electronic component in the y direction is not limited by the holding and guiding members. In this way, it is made possible to handle large electronic components and to insert not only flat ceramic condensers but also other various electronic elements differing in shape and 2a size, such as cylindrical chemical condensers, Mylar condensers, peaking coils and resistances, into printed circuit boards.
The present invention, as will be described below, prevents damage of the electrical components due to an excessive force imposed thereon and prevents them from being loosely attached because of too small a fastening force. ~hen a variety of electronic components differing in shape and size are inserted, the pressing force need not be adjusted for different com-ponents, whereby it is made possible to handle many kinds of electronic components at a high efficiency and to perform the inserting operation automatically with ease.
3Q The present invention also permits the insertion density of electronic components to be remarkably enhanced.

1~6Z893 As is shown in Figs. 1 and 2, electronic components 17, each com-prising an electronic element 64 and parallel leads 53, are arranged at equal pitches in parallel to one another on a long web base 65, and they are fixed by an adhesive tape 66 and feed holes 32 are formed through the base 65 and tape 66. Thus, an electronic component web carrier 3 is formed. In the present invention the electronic components 17 are automatically inserted into a printed circuit board 19 by using such electronic component web carrier 3.
The structure and function of the entire inserting machine is first outlined. Referring to Fig. 8, an inserting machine 1 and a reel holding board 2 are arranged parallel to each other, and they are automatically operated according tc a predetermined program by an NC control apparatus (not shown) disposed separately. A plurality of reels 4 having the electronic component web carrier 3, as shown in Fig. 1, wound thereon, are rotatably supported on shafts extending from the board surface perpendicularly thereto.
Different kinds of electronic components may be wound on the respective reels; for example, condensers and resistors may be wound on these reels.
Alternatively, we6 carriers 3 carrying different capacitance condensers may be wound on the reels 4. The electronic web carriers 3 unwound from the respective reels 4 are held horizontally and in parallel to one another through guide rollers 5 and feed rollers 6, and they are introduced into the inserting machine 1 through guides 7.
As shown in Fig. 13, the inserting machine 1 comprises a supply assembly 8, a transferring assembly 9, an inserting assembly 10, a table assembly 11 and a frame 12. The structures and functions of these constitu-ents of the inserting machine 1 will now be outlined by reference to Figs. 1 and 8 to 13.
In the supplying assembly 8, electronic component web carriers 3 fed into the inserting machine 1 are held, and according to an NC program, a predetermined kind of an electronic component web carrier 3 is selected and it is cut in succession into respective electronic components along the line A-A in Fig. 1, and these electronic components as shown in Fig. 3 are fed to the transferring assembly 9. In the transferring assembly 9, the electronic components fed from the supplying assembly 8 are gripped by means of a rotary disc 14 rotating intermittently with an axis 13 inclined by 45 to the horizontal plane and a plurality of chucks lS disposed around the rotary disc 14. While they are being transferred under rotation, excessive leads below the line B-B in Fig. 4 are cut off by a cutter 16 ~see Fig. 8? to form electronic components 17 as shown in Fig. 5. Then the electronic components 17 are delivered to the inserting assembly lO while they are held in the vertical state. In the inserting assembly 10, operations includes gripping the received electronic components 17, pressing them down in the vertical direction and inserting the leads of the electronic componènts 17 into predetermined holes (including in the case of a head rotating type inserting assembly, the rotating of the electronic components 17 by 90 around a vertical shaft according to the NC program in addition to the fore-going operations? are performed. In the table assembly ll, a printed circuit board 19 in which electronic components 17 are to be inserted is held on a table 18, and the table 18 is moved on the horizontal plane in the directions x and y according to the NC program so that predetermined openings on the printed circuit board 19 are located just below the inserting assembly.
Further, excessive parts of leads of the inserted electronic components 17 are cut off along the line C-C in Fig. 6 by a cutting and bending member ~not shown? in the table 18, and the top end portions of the leads are bent perpendicularly on the back side of the printed circuit board l9 to fix the electronic components 17 as shown in Fig. 7. The foregoing assemblies are attached to and held by the frame 2 to protect these assemblies. The fore-going automatic inserting machine is described in detail in the specification of our Canadian patent application No. 249,354 filed The inserting assembly 10 will now be described in detail.

One embodiment of the inserting assembly is illustrated in Figs.
14 (front view), 15 (bottom view in which a lead holding and guiding assembly 21 is omitted) and 16 (side view). The inserting assembly 10 comprises a frame 23 attached to a stand 22 fixed to the frame 12 in Fig. 13, upper and lower slider assemblies 24 and 25 supported for independent movement on the frame 23, a lead holding and guiding assembly 21 rotatably supported on the lower slider assembly 25 around a vertical shaft thereof, and a push bar assembly 26 supported along the upper slider assembly 24 and lead holding and guiding assembly 21.
The upper slide assembly 24 is supported so that it is allowed to move ve~tically along a guide rod 28 mounted on the frame 23 by means of a cylinder 27. Various cams for moving other members are disposed on the upper slider assembly 24. More specifically, on the upper slider assembly 24, there are disposed lower slider cams 29 and 30 for determining movement of the lower slider assembly 25, an opening and closing cam 34 for opening and closing outer holding and guiding members 31 and 31' and inner holding and guiding members 32 and 32' of the lead holding and guiding assembly 21, a sleeve cam 36 for determining movement of a sleeve 35 constituting a part of the push bar assembly 26, a chuck cam 37 for opening and closing chucks 15, and a clamp cam 39 for determining movement of a clamp 38 as shown in Fig. 17. In addition, lead holding and guiding assembly-rotating cams 43 and 44 for rotating the lead holding and guiding assembly 21 are disposed on a block 42 which is moved in the vertical direction together with the upper slide assembly 24 by a projection 41 held on a guide 40 as shown in Fig. 14.
The structures and functions of these cams will be described in detail hereinafter.
The lower slider assembly 25 is supported and pivoted on the frame 23 so that a body 45 of the lower slider assembly 25, as shown in Figs. 14, 16, 18 and 19, can slide in the vertical direction with respect to the frame 23. As shown in Figs. 18 and 19, the lead holding and guiding assembly 21 is rotatably supported în the body 45 at a position of a rotary sleeve 48 by bearings 46 and 47. A block 49 is mounted on the lower end of the rotary sleeve 48, and the outer and inner holding and guiding members 31 and 33 for holding the electTonic component 17 thTough the leads 53 thereof are anchored on the block 49 and an operation rod 50 for operating these outer and inner holding and guiding members 31 and 33 is mounted on the block 49 slidably in the vertical direction.
A mechanism for sliding the lower slide assembly 25 in the vertical direction will now be described by reference to Fig. 14. A roller 55 of one lever of a bell crank 54 swingably attached to the frame 23 through a pin 51 is pressed by a lower slider cam 29 moved with vertical movement of the upper slider assembly 24 and the lower slider assembly 25 is moved in the vertical direction by- a connection rod 56 rotatably attached to the other end of the bell crank 54. Supposing that the right side is convex and the left side is concave in the state shown in Fig. 14, the shape of the cam 29 comprises a short flat portion 57 extending upwardly from the lower end of the cam 29, a convex portion 58, a long fla~ portion 59, a gradually concaved inclined face 60 and a flat portion 61. Accordingly, when the roller 55 moves down on the inclined portion 60 in a concaving direction to bring down the lower slider assembly 25, the body 45 of the lower slider assembly 25 impinges on a stopper 92 mounted on the lower end of the frame 23 before the roller 55 falls in contact with the flat portion 61. A lower slider cam 30 is disposed to prevent the lower slider assembly 25 from springing up by a repulsive force when it impinges on the stopper 92.
A mechanism for rotating the rotary sleeve 48 will now be described by reference to Fig. 14. The block 42 is disposed so that it can move horizontally with respect to the frame 23 (in the direction vertical to the sheet surface of Fig. 14), and when the block 42 moves on the side of the fTont face of the frame 23 (the front side in Fig. 14), a roller 79 falls into engagement with the lead holding and guiding assembly-rotating cams 43 and 44, and when the block 42 moves to tbe side of the rear face of the frame 23, this engagement does not take place. A bar 63 is supported so that it can slide in the vertical direction in the block 42, and the lead holding and guiding assembly-rotating cams 43 and 44 are disposed on the lower end of the bar 63. Fig. 14 illustrates the state where the roller 79 is pressed to the left by the lead holding and guiding assembly-rotating cam 44, and if the bar 63 is brought down relatively to the lower slider assembly 25, the lead holding and guiding assembly-rotating cam 43 hits the roller 79 to press the roller downwardly to the right. A bell crank 80 is rotatably attached to the lower slider assembly 25 through a pin 81 and the bell crank 8Q has the roller 79 on one end and the other end of the bell crank 80 is rotatably connected to a link 82. A pin 83 is mounted on the other end of the link 82 and fits in a U-shaped groove 86 of a lever 85 attached rotatably to the lower slider assembly 25 through another pin 84.
Between the other end 85' of the lever 85 and a pin 87 of the lower slider assembly 25, a spring 88 is disposed to cbange over tbe falling position of the lever 85 to the left or right of the dead point of the lever 85 by utilizing said dead point of the lever 85. As shown in Fig. 18, the pin 83 is attached to a rack 89 which is supported slidably in the horizontal direction by a guide 90 mounted on the body 45 to rotate a pinion 91 engaged with the pin 83 and then turn the rotary sleeve 48.
A mechanism for holding electronic components in the lead holding and guiding assembly 21 will now be described by reference to Figs. 20 to 24. A pair of outer holding and guiding members 31 are swingably attached to the block 49 by means of pins 93, and presses 94 are attached to both the sides of the block 49. The presses 94 comprise stopper bolts 95 defining closed positions of the outer holding and guiding members 31 and springs 96 pressing the outer holding and guiding members 31 to each other in the closing direction. Inner holding and guiding members 33 are rotatably mounted on the outer holding and guiding members 31 through pins 97, and rollers 99 are mounted on the outer holding and guiding members 31 through pins 98, The top end portions of the outer holding and guiding members 31 are bent in the horizontal direction, and on the confronting inner faces of the top end portions of the outer holding and guiding members 31, as shown in Figs. 25 and 26, holding grooves 100 are formed and conical face guiding groo~es 101 are formed above the holding grooves 100. As in the case of the outer holding and guiding members 31, the top end portions of the inner holding and guiding members 33 are horizontally bent, and as shown in Fig.
27, conical face guide grooves 201 are formed in upper parts of the top end portions of the members 31 facing outwardly and confronting the holding grooves 100 in Fig. 25 and flat faces 202 are formed in said upper parts.
When the lead is inserted from above in the state as shown in Fig. 25, it is guided with the guide grooves 101 and 201 being as the center and intro-duced into the holding grooves 100. Thus, the lead is held and gripped by the holding and gripping member constructed by the holding grooves 100 and flat faces 202. Accordingly, it is possible to move the inner holding and guiding members 33 in the direction y with respect to the outer holding and guiding members 31 w~ile the lead is being held therein.
A cover having a guiding groove formed on the inside thereof is mounted on one surface of the block 49, and an operation rod 50 is supported in this guiding groove so that the rod 50 can slide in the vertical direction. An L-shaped lever 204 is formed on the top end of the operation rod 50. The lower end of the rod S0 is bent in a reverse L-shaped form and as shown in Fig. 24 and the upper edge of the horizontal portion of the reversed L is formed into a peaked portion 205 including inclined faces 206 and side faces 207. As seen in Fig. 23, the end of the horizontal portion of the L has a projection 208. Further, the top ends of the inner holding and guiding members 33 have two projections 209 and 210, and these projections 209 and 210 are engaged with the projections 208 to define the positions of the inner holding and guiding members 33. A hole 211 is formed on the operation rod 50, and it constitutes a click stop mechanism together with ball 212 and spring 213 of the body 49.
The mechanism for opening and closing the inner holding and guiding members 33 and outer holding and guiding members 31 will now be described by reference to Fig. 14. A roller 216 is mounted on a link 215 rotatably attached to the frame 23 through a pin 214 so that when the upper slider assembly 24 is brought down and an inclined face 217 of the opening and closing cam 34 hits the roller 216 at the last stroke of the lowering movement of the upper slider assembly 24, the link 215 is rotated to the right. A rod 218 is rotatably con-nected to the link 215, and the other end of the rod 218 is connected to a lever 219 rotatably attached to the frame 23. The other end of the lever 219 is connected to a striker 221 through a link 220. The striker 221 can slide in the vertical direction while being guided by a guide 222. As shown in Fig. 23, the striker 221 includes an upper striker 223 and a lower striker 224.
The push bar assembly 26 includes an upper push bar assembly and a lower push bar assembly. As shown in Fig. 17, the upper push bar assembly in-cludes a sleeve 35 slidably supported in the vertical direction on the upper slider assembly 24, an upper push bar 225 slidably supported in the vertical direction in the sleeve 35 by means of a bearing, stop plate 226 and coupling 227 attached to the head and lower portion of the upper push bar, a spring 228 giving a downward force to the coupling 227, and a clamp 38 swingably supported through a pin 233 by a bearing 229 attached to the sleeve 35. This clamp 38 has a roller 234 and a spring 235 and has a function of clamping a screwed por-tion 236 of the upper push bar 225 and releasing the screwed portion 236. The cross-section of the sleeve 35 and the surrounding portion thereof is illus-trated in Figs. 28, 29 and 30. The sleeve 35 is guided by a press 237.
As shown in Figs. 18 and 23, the lower push bar assembly comprises a lower push bar 238 and a pressing head 239, and a flange 240, stop plates 241 and 242 and a screw 243 are provided on the top end of the lower push bar 238.
The flange 240 is connected to the coupling 227 of the upper push rod assembly.

10628C~3 The lower push bar 238 is supported by a bearing 244 so that it can slide in the block 49 in the vertical direction. A concavity 245 suitable for pressing the head of the electronic component is formed on the lower face of the pres-sing head 239. The lower push bar 238 rotates together with the rotary sleeve 48 and this rotation is released in the coupling 227.
The mechanism for moving the push bar assembly 26 in the vertical direction will now be described by reference to Figs. 16 and 17. The sleeve cam 36 is attached to the upper slider assembly 24, and a flat portion 246, an inclined face 247, a flat portion 248 and inclined faces 249 and 250 are formed on the sleeve cam 36 from the lower end to the top and the sleeve cam 36 is arranged to move a roller 251. The roller 251 is disposed on one end of a bell crank 254 swingably supported by a pin 253 to a bearing 252 fixed to the frame 23, and the other end of the bell crank 254 is formed into a U-shaped groove 255 which is fitted in a pin 256 of the sleeve 35 so that the sleeve 35 is moved in the vertical direction with movement of the roller 251. If the position relationship between the sleeve 35 and clamp cam 39 is as shown in Fig. 17, the roller 234 is pressed and the top end of the clamp 38 is separated from the screwed portion 236 of the upper push bar 225 (screw-like convexities and concavities are formed on the surface of the screwed portion so as to ob-tain high friction). Accordingly, the movement of the bell crank 254 is trans-mitted to the coupling 227 through the spring 228, but relative movement is caused between the upper slider assembly and sleeve 35 and when the clamp cam 39 attached to the upper slider assembly 24 separates from the roller 234, the clamp 38 clamps the upper push bar 225 and the movement of the bell crank 254 is integrally transmitted to the coupling 227 directly without passage through the spring 228. Since the flange 240 integrated with the coupling 227 is not attached to the stop plate 241, the upper push bar 225 and lower push bar 238 are allowed to make relative movement by a distance corresponding to the clear-ance between the top end of the spring 243 and coupling 227. The movement of the bell crank 254 is stopped by a limit switch before the roller 251 arrives ~06Z893 at the lowest point of the inclined face 250. This position for stopping the bell crank 254 is determined by the amount pushed and stuffed of the electronic component.
As shown in Fig. 16, a chuck cam 37 is attached to the upper slider assembly 24, and the chuck cam 37 comprises a flat portion 257, an upwardly in-clined face 258, a downwardly inclined face 259 and a flat portion 260 and it is arranged to move a roller 261. This roller 261 is attached to a lever 263 rotatably supported by a pin 262 of the frame 23 so that when the roller 261 is pressed by the chuck cam 37, the lever 263 is moved and the roller 73 of the chuck cam 15 is pressed by a striker 264 mounted on the top end of the lever 263 to open a movable claw 52 and a fixed claw 67 and separate the elec-tronic component 17 therefrom and then, the chuck 15 per se is retreated to the right.
The functions of the inserting machine having the above structure will now be described from the state shown in Fig. 16 where a certain chuck 15 is caused to press an electronic component 17 by the rotary disc 14 and the electronic component 17 is located between the head 239 and the outer holding and guiding member 31.
The cylinder 27 is first operated to bring down the upper slider as-sembly 24. Then, the upper slider assembly 24 is brought down at a constant speed. During this downward movement, the respective members are caused to perform the following organic functions by various cams attached to this upper slider assembly 24.
At first, the roller 251 is loaded on the inclined face 247 of the sleeve cam 36 and the sleeve 35 is brought down. Since the inclination of this inclined face 247 is set so that the sleeve 35 makes the same movement as that of the upper slider assembly 24, there is caused no relative movement be-tween the clamp cam 39 and roller 234 and the clamp 38 is kept in the state shown in Fig. 17 and performs no clamping action. Accordingly, when the bell crank 254 pushes down the sleeve 35, the upper push bar 225 gripping the sleeve 35 with the stop plate 226 and spring 228 is brought down together with the sleeve 35, and the lower push bar 238 suspended from the flange 240 through the stop plate 241 is brought down by its own gravity together with the upper push bar 225.
Then, the lower slider assembly 25 is raised up by the convex por-tion 58 of the lower slider cam 29 to lift the outer holding and guiding mem-bers 31 and inner holding and guiding members 33, and the leads 53 of the elec-tronic component 17 are guided into the guide grooves 101 and 201 and they are held and gripped in the gripping portion between the holding grooves 100 and flat faces 202, whereby the electronic component 17 is held. During this period, the sleeve 35 is further brought down and the push head 239 of the lower push bar 238 falls in contact with the top of the electronic component 17. Further, the bell crank 254 is rotated to bring down the sleeve 35, but the lower push bar 238 is not brought down any more because it is loaded on the top of the electronic component 17. However, when the coupling 227 is brought down until it hits on the screw 243, the sleeve 35 comes to push down the lower push bar 238 through the spring 228, and when the sleeve 35 is fur-ther brought down, the spring 228 is caused to yield and a force corresponding to this yielding is imposed on the electronic component 17. When the sleeve 35 is brought down to some extent, the roller 251 arrives at the flat portion 248 and the sleeve 35 is stopped. On the other hand, the upper slider assem-bly 24 continues the downward movement and therefore, the clamp cam 39 separates from the roller 234 and the clamp 38 is caused to clamp the upper push bar 225 by the force of the spring 235. Accordingly, ~he sleeve 35 is integrated with the upper push bar 225 and the spring 228 is kept in the yielding and dead state, but the internal force is left between the movable claw 52 and fixed claw 67 and the press head 239. Even if the kind of electronic component 17 to be inserted is changed and the insertion height is changed, since the position of the flat portion 248, namely the position of stoppage of the sleeve 35, is 3Q not changed, although a higher electronic component falls in contact with the ~06Z8~3 push head 239 in an earlier stage and causes the spring 228 to yield to a larger extent and exert a larger spring force, if a spring 228 having a lower strength is appropriately chosen, it is possible to attain an appropriate spring force for any of electronic components and damages of the electronic components can be effectively prevented irrespective of the kind of electronic component to be inserted. The position of the flat portion 248 is selected so that even when a very short electronic component is inserted, after slight yielding of the spring 228 the sleeve 35 is stopped.
Substantially simultaneously with the above operation, the lever 263 is moved by the upwardly inclined face 258 of the chuck cam 37 and the roller 73 is pressed by the striker 264 to open the movable claw 52 and fixed claw 67. At the same time, the force imposed on the electronic component 17 is re-leased and the force of the spring 228 is kept in the completely dead state as the internal force. Then, the chuck 15 is retreated downwardly and the elec-tronic component 17 is completely delivered to the outer and inner holding and gripping members 31 and 33. Striker 264 is returned in the reverse direction by the downwardly inclined face 259 of the chuck cam 37. The reason for this return is that there is formed such a clearance that the striker 264 is pre-vented from hitting on the roller 73 when the rotary disc 14 rotates.
When the lead holding and guiding assembly 21 is turned around the vertical shaft, after the striker 264 is retreated downwardly to such a poin~
that the surrounding portion of the striker 264 does not hit the turning assem-bly 21, the lead holding and guiding assembly-rotating cam 43 moves the roller 79 and rotates the lead holding and guiding assembly 21 through the rack 89 and pinion 91 (see Fig. 18). This rotation is accelerated and assured by the spring 88 acting as the dead point mechanism.
Then, the sleeve 35 and lower slider assembly 25 are similarly brought down by the inclined face 249 of the sleeve cam 36 and the inclined face 60 of the lower slider cam 29, whereby the push head 239 and the outer and inner holding and guiding members 31 and 33 are brought down while keeping the same clearance therebetween and holding the electronic component 17 therebetween.
Just before the lower faces of the outer and inner holding and guiding members 31 and 33 fall in contact with the printed circuit board l9, the lower slider assembly 25 hits on the stopper 92 and is stopped. At this point, the roller 55 does not reach the flat portion 61 but leaves a certain clearance. When the lower slider assembly 25 hits the stopper 92, it tends to spring up, but is is pressed by the lower slider cam 30 and is prevented from springing up.
Since the sleeve 35 is further brought down, the electronic component 17 is pressed by the push head 239 and is allowed to slide between the holding groove 100 and flat face 202. As a result, the ends of the leads 53 are in-serted into openings of the printed circuit board 19. Then the leads 53 are further pushed down and they are bent, as shown in Fig. 6, to form a stopper 265, and at the point where this stopper 265 hits on the printed circuit board 19, by the action of the limit switch, the movement of the bell crank 254 is ceased to stop the push head 239. Then, the cutting of excessive leads and bending of cut end portions is performed from the back surface of the printed circuit board l9 by the cutting and bending mechanism (not shown) and the leads an electronic component 17 are fixed as shown in Fig. 7.
When the leads 53 are completely inserted in the openings of the printed circuit board 19 during the operation of inserting the electronic com-ponent 17, the inclined face 217 of the opening and closing cam 34 hits on the roller 216 to raise up the striker 221, whereby, as shown in Fig. 31, the lever portion 204 of the operation rod 50 is lifted up by the lower striker 224 of the striker 221. Accordingly, the projection 208 hits on the projection 209 to rotate the inner holding and guiding member 33, and the top end of the inner holding and guiding member 33 is deviated in the direction y to open inside of the holding groove 100. At first, there is a small clearance between the peaked portion 205 of the operation rod 50 and the roller 99 as shown in Fig.
24, but when the operation rod 50 is lîfted up to some extent and the inclined face 206 falls into contact with the roller 99 after the movement of the inner holding and guiding members 33 in the direction y, the outer holding and guid-ing members 31 begin to open and they open in the state where the side faces 207 are contacted therewith as shown in Fig. 32. If the lead holding and guiding assembly 21 is raised up in this state, it is possible to insert the electronic component 17 smoothly without any contact with the holding and guiding members.
This state is illustrated in a plan view of Fig. 33. The inner holding and guiding members 33 are first moved in the direction y and then they are opened in the direction x together with the outer holding and guiding members 31 to form a large open space. Further, on the right side of the x axis in Fig. 33, all the members holding the electronic component 17 ~in this case, the outer and inner holding and guiding members 31 and 33) are completely opened. AccordinglyJ even if the distance m between the electronic component 17 and adjacent electronic component 17' is small, the size t of the electronic components 17 and 17' can be increased to a maximum as long as the electronic components 17 and 17' do not contact each other. Therefore, according to the present invention, not only flat electronic components such as ceramic conden-sers but also cylindrical and prismatic electronic components can be inserted.
Thus, various electronic components such as chemical condensers, Myler conden-sers, pea~ing coils and resistors can be conveniently inserted into printed circuit boards according to the present invention.
Even when the size of the electronic component 17 is varied, if the height hl ~see Fig. 6) from the end of the lead 53 to the lower end of the stopper 265 is kept constant, the stroke for inserting the lead 53 into the printed circuit board 19 is not changed. Accordingly, even when various elec-tronic components differing in the height h2 from the lower end of the stopper 265 to the top are handled, only a small force set by the soft spring 228 is changed, and the insertion is not influenced by the force of the spring 228 at all and electronic components differing in the height h2 can be inserted by the 1062~393 same force. Further, since the insertion of the lead 53 is stopped by the limit switch at the point where the lower end of the stopper 265 hits on the printed circuit board 19, no large force is imposed on the ele~ronic component and it is effectively prevented from being damaged. Moreover, when various electronic components differing in size are inserted, no particular adjustment need be made for the respective electronic components, and therefore, automa-tion of insertion of various kinds of electronic components can easily be accomplished.
Another embodiment of the lead holding and guiding assembly and push bar assembly in the present invention will now be described by reference to Figs. 34 to 45.
As shown in Figs. 34 to 37, a lead holding and guiding assembly 350 comprises a pair of outer holding and guiding members 352 pivoted on a block 348 through pins 351 and a pair of inner holding and guiding members 354 at-tached to the inner faces of the outer holding and guiding members 352 through pins 353. A compression spring 355 is laid out betweenithe upper holding and guiding members 352 and they are urged by the spring 355 so that their top ends are opened. The degree of opening in the outer holding and guiding mem-bers 352 can be adjusted by a stopper hold 356 disposed on the side of the block 348. Opening and closing cams 357 are disposed on the outer holding and guiding members 352 to open and close the outer holding and guiding members 352. Each of the outer and inner holding and guiding members 352 and 354 has a vertical portion 352A or 354A extending substantially in the vertical direction and an inclined portion 352B or 354B extending downwardly and obliquely (about 45) from the vertical portion 352A or 354A. In each of the outer holding and guiding members 352, an inwardly bent L-shaped portion 352C is formed on the top end of the inclined portion 352B as shown in Figs. 38 and 39. A holding groove 358A and a guiding groove 359A are formed on the base of the bent por-tion 352C. As shown in Fig. 40, a holding groove 358B and a guiding groove 359B are formed on the angular part of the inclined portion 354B of each inner

-2~-~.o6Z893 holding and guiding member 354 so that when the top end face of the inclined portion 354B falls in contact with the bent portion 352C, both the grooves 358A and 358B form a gripping hole 360 and both the guiding grooves 359A and 359B form a guiding face 361 along the entire peripherys thereof. Leads of an electronic component 17 delivered from a chuck mechanism 15 are received by the guiding face 361 and held by the gripping hole 360 as shown in Figure 16.
Referring to Figures 34 to 37, an operation rod 362 is mounted on the block 348 so that it can slide in the vertical direction, and an L-shaped en-gaging portion 363 is formed on the top of the operation rod 362 and a sphe-rical projection 364 is formed in the lower portion of the operation rod 362.
The spherical projection 364 is arranged so that when it falls in contact with the inner faces of the opening and closing cams 357 for the outer holding and guiding members 352, it opens the outer holding and guiding members 352.
Presses 366 for the outer holding and guiding members 352 are mounted on both the sides of the operation rod 362, respectively, through pins 365 and spheri-cal projectlons 367 alling in contact with the outer faces of the opening and closing cams 357 are formed on the inner faces of the presses 366. A tension spring 368 is laid out between both the presses 366 for the outer holding and guiding members 352. Since the tension spring 368 is arranged so that its elastic force is larger than the elastic force of the compression spring 355 laid out between the outer holding and guiding members 352, when the spherical projections 367 are kept in contact with the outer faces of the opening and closing cams 357, the outer holding and guiding members 352 are kept closed.
Adjustment bolts 369 are disposed on the presses 366 for the outer holding and guiding members 352 to adjust the pressing degree. Spring pins 370 are further mounted on the operation rod 362. These spring pins 370 are engaged with the inner holding and guiding members 354 and press them in the closing direction by the spring force, and these springs 370 also operate the inner holding and guiding members 354 cooperatively with the vertical movement of the operation rod 362. A click stop mechanism comprising a ball 371 and a spring 372 is mounted on the block 348 to define the vertical position of the operation rod 362.
As illustrated in the foregoing embodiment shown in Figs. 14, 16 and 18 and as shown in Fig. 37, a striker 221 is mounted on the frame 23 vertically movably to operate the operation rod 362. An opening and closing cam 34 is in-tegrally formed on an upper slider assembly 24 and a link 215 having on one end thereof a roller 216 falling in contact with the opening and closing cam 34 is mounted on the frame 23. The other end of the link 215 is connected to one end of a lever 219 pivoted on the frame 23 through a rod 218, and the other end of lever 219 is connected to the striker 221 through a link 220. In this arrange-ment, when the upper slider assembly 24 is located at the uppermost position, the striker 221 is located at a lowered position, and when the upper slider assembly 24 is brought down considerably, with climbing of the rollers 216 along the inclined face of the opening and closing cam 34, the striker 221 rises up to lift up the L-shaped engaging portion 363 of the operation rod 362.
As shown in Figs. 36 and 37, a lower push bar 324 pierces through the block 348 and a push bar sleeve 387 is slidably inserted in the lower end of the lower push bar 324, and a sleeve cover 389 is attached to the push bar sleeve 387 through a pin 388. Further, a compression spring 390 urging the pin 388 dGwnwardly is disposed in the push bar sleeve 387. Thus, the push bar sleeve 387 is urged by the compression spring 390 to project downwardly, and it is contracted and elongated in the region C. Owing to this contraction and elongation, the lower push bar 324 can be brought down until the sleeve cover 389 falls in contact with the top end of the lead holding and guiding assembly 350. Accordingly, it is possible to perform insertion irrespective of the size of the electronic component supported by the lead holding and guiding assembly 350.
As in the foregoing embodiment, the lead holding and guiding assem-bly 350 is arranged so that it can rotate together with the block 348 with the ~062893 lower push bar 324 being as the center of rotation so as to accomplish change-over of the inserting direction.
Operations of the above-mentioned second embodiment will now be des-cribed by reference to Figs. 14, 16, 17, 18,41 and 45. As the cylinder 27 is operated and the upper slider assembly 24 is brought down, the bell crank 254 is turned to the left by the inclined face 247 of the sleeve cam 36 and the sleeve 35 is brought down, whereby the lower push bar 324 is driven downwardly as indicated by an arrow D in Fig. 41 through the spring 228 and coupling 227.
The roller 55 falling in contact with the lower slider cam 29 separates from the flat portion 57 of the lower slider cam 29. Accordingly, the bell crank 54 is slightly rotated to the right, whereby the lower slider assembly 25 is raised up and the lead holding and guiding assembly 350 moving vertically to-gether with the lower slider assembly 25 is driven upwardly as indicated by an arrow F. Accordingly, the electronic component 17 held by the chuck mechanism 15 is pressed by the sleeve cover 389 and the leads 53 of the electronic com-ponent 17 are guided in and held by the gripping holes 360 between the outer holding and guiding members 352 and inner holding and guiding members 354.
During the foregoing inserting operation, owing to buffer actions of the springs 228 and 390, the electronic component 17 is prevented from being damaged and insertion of the electronic component 17 is accomplished under an appropriate pressing force.
When the upper slider assembly 24 is further brought down, the bell crank 254 is further turned to the left by the inclined face 249 of the sleeve cam 36 and also the sleeve 35 is brought down. At this point, since the upper push bar 225 is clamped by the clamp 38, the movement of the sleeve 35 is trans-mitted to the lower push bar 324 through the upper push bar 225 and coupling 227. Simultaneously, since the bell crank 54 is turned to the left by the in-clined face of the lower slider cam 29, also the lower slider assembly 25 is brought down. Since the inclined face 249 of the sleeve cam 36 and the inclined face of the lower slider cam 29 are arranged so that the descending speed of the sleeve 35 is equal to the descending speed of the lower slider assembly 25, both the lower push bar 324 and the lead holding and guiding assembly 350 are brought down as indicated by arrows G and H in Fig. 42, and the leads 53 of the electronic component 17 are inserted into the printed circuit board 19.
Then, by the action of the opening and closing cam 34, the link 215 is turned to the right and the striker 221 is lifted up. At this moment, the operation rod 362 mounted on the block 348 is driven upwardly, and the inner holding and guiding members 354 engaged with the spring pins 370 are turned as indicated by an arrow I in Fig. 43 to release gripping of the leads 53.
The downward movement of the lower push bar 324 is continued for a while as indicated by an arrow J in Fig. 44 even after stopping of the lead holding and guiding assembly 350, whereby the leads 53 are inserted into the printed circuit board 19 sufficiently deeply.
Since the push bar sleeve 387 inserted in the lower push bar 324 is elongated and contracted in the region C shown in Fig. 37, the push amount of the lower push bar 324 can easily be set, and a variety of electronic compo-nents differing in shape and size in a broad range can be inserted. In par-ticular, electronic components having a very small outer shape, such as straight lead ceramic condensers, can be inserted conveniently.
Then, the inner faces of the opening and closing cams 357 of the outer holding and guiding members 352 are pressed by the spherical projections 364 on the top end of the operation rod 362, and the outer holding and guiding members 352 are outwardly opened as indicated by an arrow K in Fig. 44. When the operation rod 362 further rises, the engagement between the outer holding and guiding members 352 and the presses 366 therefor is released and the elon-gating spring 368 has no action on the outer holding and guiding members 352 any more. Accordingly, the outer holding and guiding members 352 are further opened in a direction indicated by an arrow K by the action of compression spring 355.
After the foregoing operations, as indicated by arrows L and M in Fig. 45, both the lower push bar 324 and the opened lead holding and guiding assembly 350 are returned to the rising positions. Thus, a series of opera-tions for inserting the electronic component 17 into the printed circuit board 19 have been completed.
According to the above-mentioned embodiment, since the operation of opening the outer holding and guiding members 352 in the lead holding and guiding assembly 350 is performed in two stages and since necessary and minimum opening is forcibly accomplished by a mechanical force of cam means and further opening is accomplished by an elastic force of the compression spring 355, even if the outer holding and guiding members 352 fall in contact with the subse-quent adjacent electronic component when they are opened, they do not damage the adjacent electronic component at all. Therefore, the distance between two adjacent electronic components can be remarkably narrowed. Further, since the top ends of the outer and inner holding and guiding members 352 and 354 are formed into inclined portions 352B and 354B extending downwardly and obliquely, even if a coaxial type electronic component has been inserted in advance in the vicinity of the insertion position, a subsequent electronic component can be inserted conveniently.
Still further, in the above-mentioned embodiment, by virtue of the feature that the push bar sleeve is disposed in the lower push bar and is urged downwardly by the spring and the sleeve cover is mounted on the push bar sleeve so that the sleeve cover presses the electronic component, it is possible to insert a variety of electronic components differing in the size and shape in a broad range assuredly, and there is attained an advantage that electronic com-ponents having a very small outer shape can be inserted assuredly.

Claims (8)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In a machine for automatically inserting parallel lead type elec-tronic components into holes in a printed circuit board, the improvement comprising inserting means for receiving an electronic component at a pre-determined position and inserting same into an inserted position, said inserting means including (a) a frame, (b) driving means mounted on said frame, (c) first slider means driven by said driving means to move vertically, (d) second slider means movable vertically in response to the movement of said first slider means, (e) lead holding and guiding means for holding and guiding parallel leads of said electronic component, said lead holding and guiding means being movable vertically with the movement of said second slider means, and said lead holding and guiding means including a pair of outer holding and guiding members and a pair of inner holding and guiding members, said pair of outer holding and guiding members being arranged to engage cooperatively said pair of inner holding and guiding members and thereby effect a guiding and gripping of said electronic component parallel leads therebetween at said predetermined position, and (f) push bar means movable vertically in response to the movement of said first slider means, said push bar means being arran-ged to engage said electronic component when same is guided and gripped by said lead holding and guiding means and displace said electronic component parallel leads from said predetermined position to said inserted position under the guiding control of said lead holding and guiding means.

2. A machine as claimed in claim 1, wherein each of said outer hold-ing and guiding members has a holding groove and a conical face guiding groove above said holding groove and each of said inner holding and guiding members has a holding flat face and a conical face guiding groove above said holding flat face.

3. A machine as claimed in claim 1, wherein each of said outer holding and guiding members has an inwardly bent L-shaped portion on the top end thereof, said L-shaped portion having a holding groove and a conical face guiding groove above said holding groove on the base portion thereof, and each of said inner holding and guiding members has a holding groove and a conical face guiding groove above said holding groove on the corner of the top end thereof, each of said inner holding and guiding members being pivoted on the inner side face of the corresponding outer holding and guiding member so that each of said top ends of the inner holding and guiding members falls in con-tact with the inner face of said L-shaped bent portion of the corresponding outer holding and guiding members.

4. A machine as claimed in claim 1, wherein said push bar means includes a sleeve movable vertically in response to said first slider means, an upper push bar slidably supported in said sleeve, a spring interposed between said sleeve and said upper push bar, a lower push bar connected to the lower end of said upper push bar and a clamp mounted on said sleeve, said clamp controlling a sliding movement of said upper push bar supported in said sleeve.

5. A machine as claimed in claim 1, wherein said lead holding and guid-ing means is adapted to be rotated about the vertical axis to effect angular reorientation of said electronic component prior to displacement of same to said inserted position.

6. A machine as claimed in claim 2, wherein said lead holding and guid-ing means includes hold releasing means for releasing the gripping of said lead holding and guiding means.

7. A machine as claimed in claim 3, wherein said lead holding and guid-ing means includes a spring for urging and opening said outer holding and guid-ing members, an operation rod movable vertically and outer holding and guiding member-pressing members for defining the degree of opening of said outer hold-ing and guiding members, and thereby said outer holding and guiding members being forcibly opened by the first moving action of said operation rod and said pressing members being released from said outer holding and guiding members by the second moving action of said operation rod to open said outer holding and guiding members by said spring.

8. A machine as claimed in claim 4, wherein said lower push bar includes a push bar sleeve inserted slidably in the lower end portion of said lower push bar, a spring for urging said push bar sleeve downwardly and a sleeve cover disposed on the lower end of the push bar sleeve and for pushing the electronic component in said inserted position.