Insertion apparatus for pressing a ring into a pipe

Abstract: Apparatus (3) for pressing an inner ring (2) into a pipe (1) comprising a clamp base (8), a means (5) for pressing the inner ring along the axis of the pipe and a means for generating a force (6), all of them being located on the apparatus body wherein advancement of the pressing means permits an inner ring (2) held in the pressing means to be inserted into the end of a pipe which is held fixed in a clamp base (8). The pressing means has a ring holder (16) at its forward end for detachably holding the inner ring (2) to be inserted. The force generating means are supported by the apparatus body and comprise a pinion (21) engaged with a rack (5a).

Description: The present invention relates to apparatus for pressing an inner ring into a pipe to form a bulge around the pipe, which is of synthetic resin. There are many arrangements for forming an external bulge in the end part of a pipe section which is to be connected to another pipe section so that such a bulge prevents any of the connected pipe sections from slipping out of the joints between the pipe sections. Although the prior art has proposed the formation of a bulge on a pipe in one operation, there is difficulty in forming the bulge in one operation, particularly if the pipe is made of a fluoresin, which is notoriously difficult to work. It is a primary object of the invention to provide apparatus for pressing an inner ring into a receiving pipe which requires only one step to accurately perform the insertion work without distortion, which can be easily operated by one operator without imposing any extraordinary burdens upon the operator. It is another object of the invention to provide apparatus for pressing an inner ring to be inserted into a receiving pipe which is easy to handle, inexpensive and of a simplified and small structure. It is another object of the invention to provide apparatus for pressing an inner ring into a receiving pipe which is adapted to handle a variety of insert ring and receiving pipe sizes. FR-A-1161289, forming the base for the preamble of claim 1, discloses pressing apparatus for forming a widened socket at the end of a pipe of malleable metal such as copper by the insertion of a mandrel. The apparatus comprises a clamp for fixedly holding the pipe, pressing means actuated by a rack extending along the axis of said pipe and a means for moving said rack, said means for moving said rack including a pinion to be engaged with said rack, so that the insert is inserted into said pipe when said rack is moved towards the end of said pipe. Apparatus in accordance with the present invention is characterised in that the insert is an oversized ring and the pipe is of a synthetic resin such as fluoresin having an internal diameter less than the largest diameter of the ring, the ring being left in the pipe when the rack is smoved away, in that said pressing means comprises a detachable and replaceable ring holder comprising a ring-engaging part and a pressing part adapted to support a ring and in that said rack extends horizontally and has downwardly extending teeth, the pinion being mounted in a covered box with a bore having bearings in which the rack slides. The ring supported on the holder is smoothly inserted into the pipe by the rack on rotation of the pinion. After the inner ring has been completely inserted in the receiving pipe, the pinion rotation is reversed and the rack is gradually retracted, whereby the inner ring is detached from the retreating ring holder. The ring holder being detachably mounted may be removed and replaced for different sizes of rings and pipes. The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompaning drawings. Figure 1 is a partial longitudinal side view of the apparatus according to the invention after having completed the insertion of an inner ring into a receiving pipe. Figure 2 is a side view of the apparatus of Figure 1; illustrating the commencement of the insertion process; Figure 3 is a longitudinal rear view taken along the line III - III of Figure 2; Figure 4 is a longitudinal rear view taken along the line IV-IV of Figure 2; and, Figure 5 is a cross-sectional view illustrating the clamping of a pipe having a smaller diameter than the pipe shown in Figures 1 - 4. Referring first to Figures 1 and 2, an inner ring 2, of ring-like shape, is to be inserted into the end of a receiving pipe 1, which may be a resin-made pipe. Inner ring 2 includes a portion 2a which bulges out to be slightly larger in diameter than the inner diameter of a receiving pipe 1 and also has an enlarged end part 2b which is adapted to engage the end of the receiving pipe 1 once the inner ring 2 has been inserted into pipe 1. Generally, the material for the inner ring 2 is selected to be the same as that for pipe 1. As shown in Figs. 1-4, the apparatus 3 for pressing the inner ring 2 into receiving pipe 1 comprises the apparatus body 4, means 5 for pressing the inner ring 2 along the axis of the receiving pipe 1, and means 6 for generating the required force to insert the inner ring 2 into the receiving pipe 1. The apparatus further includes a clamp base 8 and a gear box 9 both of which stand on the opposite ends respectively of base 7. The clamp base 8 is constructed of a structure being divided into two portions, namely a fixed clamp part 8a, which is attached to base 7, and a movable clamp part 8b. The movable clamp part 8b is pivoted about a clamp pin 10 as a pivot point and is operated to be pivoted between a position of clamping the pipe 1 (as shown by the dotted lines in Fig. 4), where the movable clamp part 8b engages the fixed clamp part 8a, and a position of unclamping the pipe 1 (as shown by the solid line in Fig. 4) where the upper face of the fixed clamp 8a is pivoted to an open position. Semi-circular clamp recesses 8'a and 8'b into which frictional lining pieces 11a and 11b, such as a rubber sheet or the like are inserted, are formed on the opposite faces of the clamp parts 8a and 8b respectively, so that the receiving pipe 1 to be clamped between the clamp parts 8a and 8b may be firmly clamped in a fixed position. Lever-like knobs 12a and 12b are provided to protrude from the clamp parts 8a and 8b, respectively, to cooperate with a locking lever 13 which is pivotably mounted on the base of knob 12a. When the locking lever is rotated about its pivot on knob 12a it will engage knob 12b by way of the groove 13a, if the movable clamp part 8b assumes the clamping position shown in the dotted lines in Figure 4. If the diameter of pipe 1 is smaller than the clamp grooves 8'a and 8'b as shown in Figure 5, an insert 14, having a C-shaped section made of an elastic material such as urethane, is fitted to surround the receiving pipe 1 to be clamped, whereby the receiving pipe may be firmly clamped in the clamp base 8. The insert 14 opposite the opening of the C-shape has a cut-away portion 14a. Referring now to Figures 1 and 3, a bore 9a, and a space 9b containing a pinion 21, are all a part of a gear box 9. The space 9b containing the pinion 21 has an opening on one side face of the gear box 9 and such an opening is covered with a cover 9c. Pressing means 5 for pressing the inner ring 2 is comprised of a shaft having its lower face equipped with a rack 5a extending through the bore 9a and is slidably movable therein and supported by the bearings 15. The pressing means 5 has a ring holder 16 mounted at its front end. The ring holder 16 comprises an inner ring engaging and inserting part 16a and an enlarged rim (elevated ledge) 16b to engage with and press the enlarged end 2b of the inner ring 2, and a spindle 16c fit detachably into a mounting hole 5b on the front end of the pressing means 5. Ring holders 16 of varying dimensions may be thus mounted into the mounting hole 5b of the pressing means 5. Ring holder 16 is secured, or detached, by the use of a fixing screw 17. A threaded bolt 19 protrudes from the rear of gearbox 9 through a guide plate 18 fixed to the rear end of the pressing means 5 and the stroke of the pressing means 5 may be adjusted by suitably rotating bolt 19 into, or out of, the gear box 9. As shown in Figs. 1-3, a pivot axle 6a is inserted into and supported in the wall of a gear box 9 and the lid 9c by way of the bearings 20. The pinion 21 is fixed to the pivot axle 6a by means of a pin 22 thus assuring that when axle 6a is rotated by rotating lever 6, pinion 21 will rotate and move the rack 5a backwards or forwards as desired. In operation, a ring holder 16 having an inner ring 2 mounted thereon is advanced toward the end of receiving pipe 1 held in clamp base 8. As the rack 5a advances the ring holder 16 is pressed into the end of receiving pipe 1 (such a condition is shown in Fig. 1) and ring 2 is pressed into the receiving pipe 1. After the enlarged end part 2b of the inner ring 2 engages the end face of receiving pipe 1, further rotation of lever 6 is stopped and the lever 6 is rotated in the reverse direction to withdraw ring holder 16 from the pipe.

Claims: Apparatus for pressing an insert into a pipe (1), such apparatus comprising a clamp (8) for fixedly holding said pipe (1), pressing means, actuated by a rack (5a) extending along the axis of said pipe and a means for moving said rack (5a), said means for moving said rack including a pinion (31) to be engaged with said rack, so that the insert is pressed into said pipe when said rack is moved towards the end of said pipe, characterized in that the insert is an oversized ring (2) and the pipe (1) is of a synthetic resin such as fluoresin having an internal diameter less than the largest diameter of ring (2), the ring (2) being left in the pipe (1) when the rack is moved away, in that said pressing means comprises a detachable and replaceable ring holder (16) comprising a ring-engaging part (16a) and a pressing part (16b) adapted to support a ring (2) and in that said rack (5a) extends horizontally and has downwardly extending teeth, the pinion (21) being mounted in a covered box (9) with a bore (9a) having bearings (15) in which the rack (5a) slides. Apparatus according to Claim 1, wherein clamping recesses (8a) and (8b) of clamp (8) include friction lining pieces (11a, 11b) to enhance the clamping grip on the pipe. Apparatus as claimed in Claim 1 or Claim 2 wherein the clamp (8) includes a C-shaped insert (14) made of elastic material to hold a pipe with a diameter substantially smaller than clamping recesses (8a) and (8b). Apparatus as claimed in Claim 3 wherein the insert (14) has a cut-away part (14a) opposite the opening of the C-shape. A method of forming a bulge in a pipe (1) made of fluoresin or other synthetic resin using apparatus according to Claim 1, such method comprising the steps of inserting an oversized ring (2) on holder (16) into the pipe end and subsequently withdrawing the holder (16) leaving the ring (2) in pipe (1) to form the bulge.

Inventors: NISHIO KIYOSHI, NISHIO, KIYOSHI
Applicants: NIPPON PILLAR PACKING, NIPPON PILLAR PACKING CO., LTD.
Application year: 1991
Main classification: B21D39
IPC codes: B21D39