IL105443A - Hand tool for punching holes in plastic irrigation pipes - Google Patents

Description

HAND TOOL FOR PUNCHING HOLES IN PLASTIC IRRIGATION PIPES n>opi?£j n> >p\yn rmsa -nvrfc Background of the Invention 1. Field of the Invention The invention generally relates to producing holes, and more specifically relates to a hand tool for punching holes preferably in plastic irrigation pipes of which there are two types. The one leaves the factory already equipped with drips installed at regular intervals and the second is a so-called plain pipe that has to have the holes punched in it when the pipe is laid out in the field or garden and have the drips mounted afterwards. The invention relates substantially to the second type of pipes although it can be used in connection with the first type as well, when there may be necessity to add holes. The invention also can be used for producing holes in any flexible plastic piping. 2. Description of the Prior Art Hand tools for the drilling of holes or punching of holes in agricultural plastic irrigation pipes are known. They are formed as a short tubular cutting element connected to a handle, much like a short screwdriver handle and the use therof presents several difficulties. In order to use it successfully one has to exercise physical effort, concentration and expertise in order that the hole punched should not go through to the other side of the pipe, and that the device should allow mounting on the pipe in such a manner that there is achieved punching in the diametral crossection. Another disadvantage associated with known devices lies in the fact that the cutting element is unprotected and can easily be blunted and, in so being unprotected, also proves to be dangerous and accident-prone.

Over the last few years new improved hole punchers have been designed and registered by myself as registered designs (see appendix page 1) and have solved the deficiencies mentioned above, although each tool is limited to specific sized pipes; one is suitable only for 16 mm. (5/8") pipes, one for 16-20 mm. (5/8"-3/4") pipes, and another for 25-32 mm. (1"-1.25") pipes. Some of these tools have a slidably mounted adaptor that fits into the tool from the side and gives it the versatility of use with two pipe sizes.

Another disadvantage associated with the above mentioned hole puncher is connected with its relatively short service life. The round-shaped male projection (Fig.llB) on the sliding adaptor fitted into the female recess on the body of the tool from the side (Fig.llA) and this proved to be a point of weakness as fatigue stresses developing in the upper jaw during the punching action were transferred via the pipe to the lower jaw (Fig.llX) thus occasionally causing a crack or even a complete split (38) from the point of the recess across to the bottom of the tool (Fig.llA).

Summary of the Invention Against the described background it is therefore a general object of the invention to provide an improved hand operated tool that sufficiently improves all disadvantages mentioned above. More specifically the object of the invention is to provide a puncher suitable for producing holes in plastic pipes of different diameters by means of a single tool. More specifically the object of the invention is a selection of sliding adaptors that fit into the tool from the front and not from the side, since inserting the sliding adaptors from the front is easier. The above mentioned object is achieved by means of preferably T-shaped male projection (12) and T-shaped female recess (11) members mating each other. This achieves the object of strengthening both the tool and the sliding adaptor, which achieves the object of the invention to provide a puncher with improved tool life. Still another object of the present invention is to provide a puncher of simple construction which is easy and comfortable to use, requiring minimal physical effort and expertise. Yet another object is to provide a puncher comprising of a tubular cutting element in sizes according to the users' needs. The cutting element can be exchanged with another spare cutting element of a different size stored in the open cavity (31) in the rear end of the body of the tool, by simply extracting the hinge pin (6) that holds the handle (2) to the body of the tool ( 1 ) .

The above mentioned objects are achieved by means of a hand operated tool constructed so that the irrigation pipe or any flexible pipe is placed in the jaw (21) and the exertion of hand-clasp pressure causes a lever action that punches the hole in the pipe. Into this ring-shaped hole, irrigation drips or sprinklers are inserted.

The accompanying drawings, which are incorporated in and form a part of the specification, illustrate preferred embodiments of the present invention and together with the description, serve to explain the principles of the invention. In the drawings : Brief Description of the Drawings Figure 1 : A general view of the whole tool.

Figure 2 : Partial longitudinal cross-section view of the tool, shown in Fig. 1.

Figure 3: The cutting element together with tubular holder implemented in the tool, shown in Fig. 1.

Figure 4 : Front view showing the T-shaped female recess for insertion of the sliding adaptor.

Figure 5 : A & B: Respectively front and side views of the sliding adaptor provided with a T-shaped male projection mating with T-shaped female recess shown in Fig. 4.

Figure & Side views of sliding adaptors intended for use Figure with pipes of different diameters.

Figure 8: A & B: Respectively front and side views of sliding adaptor showing T-shaped male projection provided with lateral stopper for use with special drip pipes .

Figure 9: A & B & C: Respectively exploded cross sectional views of the top part of the body of the tool, the cutting element and the tubular holder and spring.

Figure 10: A & B & C: Alternative configurations of male and female mating members in sliding adaptors.

Figure 11: Isometric view of sliding adaptor and lower jaw of the earlier unsuccessful configuration which this present invention achieves to improve.

Detailed Description of the Parts of the Tool and How they Operate With reference to Fig. 1 the punch consists of Body (1) preferably made of high strength moulded plastic material onto which all the other parts of the tool are connected.

The T-shaped female recess in Fig.4 (11) allows for inserting S~ the male projection (12) of the sliding adaptors into the lower jaw in the frontal part of the body of the tool.

At the rear end of the body is the open cavity (31) which provides the storage place for the spare cutting element. The indentation (30) allows for easy access to and extraction of Io the spare cutting element. The jaw (21) is the place into which the pipe is inserted and held when the hole is punched into it. It is advantageous to provide the inwardly facing surface of the upper jaw with a rim (25) strengthening the body of the tool. In addition the tool might have two 1·Υ" strengthening supports (26 & 27). There is provided a hole (28) in the frontal part of the body wich connects the body with a handle (2) as to ensure its pivoting about the pin ( 6 ) . The handle is preferably made of high strength moulded plastic material, shaped to fit comfortably into the palm of the hand and has a protruding knob (34) that ensures correct hand position. There are two small guiding tabs (15) on the underside of the handle that prevent the cutting elements' tubular holder (3) from being rotated about. A small step (29) formed on the outermost extremity of the ¾T handle limits the opening span of the handle. The tubular holder (3) for the cutting element is also preferably made of moulded plastic material. The cutting element (4) is afixed to one end of the holder where there is provided a step (22) that doesn't allow the cutting element to go in any further. "io At the other end there is an exit opening (9) that allows the waste plastic cut out of the pipe to be discharged through it. The exit opening always faces in the direction of the handle. The cutting element (4) is usually made of hardened steel and is permanently mounted by pressure into the interior of the tubular holder (3). The cutting element as shown in Fig.9B may be provided with circular grooves around it (23 & 24) that prevent it from falling out of the interior of the holder once pressurised in. The sharpness of the cutting extremity of the element and its proper geometry allow for the waste plastic cut out of the pipe to be pushed up and be discharged out from the top of the exit opening (9) at the top of the tubular holder. Removal of waste plastic cut-outs (35) takes place after the interior of the cutting element fills up after punching several holes (Fig.9B). The spring (5) is preferably made of tempered steel and its function is to return the cutting element fixed in the tubular holder back to its resting position on completion of the hole punching operation. The spring embraces the tubular holder and cutting element and fits into the tubular cavity (36) in the top of the body of the tool. The step (37) ensures that the spring stays in its proper place. The hinge pin (6) is also preferably made of moulded plastic material and holds the handle to the body of the tool. The groove (13) at the end of the pin allows it to be easily dismantled and replaced. The reinforcing oppositely located protrusions (14) prevent the pin from falling out. There is a selection of sliding adaptors (7) also preferably made of moulded plastic material that each have an identical T-shaped male projection (12) on their underside extremity that mates with the T-shaped female recess (11) provided in the lower jaw of the body of the tool. The configuration of the female recess and the male protrusion is formed as to provide their mating and reliable mounting and fixation of the sliding adaptor onto the body. The preferable configuration shown in Figs. 4 and 5 and 6 are T- shaped protrusion and recess, but it should be understood that other configurations are possible as well, such as for example, prismatic V-shaped, or other shapes as shown in Fig.10. By virtue of the direction of the said recess and projection along the lower jaw, there is achieved the possibility of elimination of fatigue stresses developing at the upper jaw during the punching action, and transferring via the pipe to the lower jaw. The exterior size of each sliding adaptor is made to suit an individual pipe diameter .

See Fig. 5 for 25 mm. (1") pipes (16).

Fig. 6 for 20 mm. (3/4") pipes (17).

Fig. 7 for 16 mm. (5/8") pipes (18).

Fig. 8 for special drip pipes (19).

Fig. 2 is without an adaptor for 32 mm. (1.25") pipes (20) In Fig. 8 there is shown an additional embodiment of the sliding adaptor provided with a U-shaped inwardly facing surface provided with a step (32). This embodiment is suitable for punching holes in drip pipes, which have sections of enlarged diameter, and by virtue of this step it is ensures that the tool is always held in its correct position with respect to the pipe. The going-through hole (33) in the U-shaped surface allows the cutting element to pass through it when the handle (2) is pressed down. The spare cutting element (8) has an open storage cavity (31) provided for it in the rear part of the body of the tool that is shaped to fit the cutting element and tubular holder.

These parts are easily pushed into the storage place and held there by means of protrusions (10) made on the inwardly facing opposite surfaces of the cavity.

Operation of the Invention A. Choose the sliding adaptor of suitable size required for the diameter of the pipe to be used. Slide the adaptor into place mating the male projection with the female recess.

B. Fit the pipe into the open jaw (21) of the body of the tool .

C. Holding the tool in the palm of the hand exert hand-clasp pressure causing a lever action that brings the handle (2) to press down on the cutting elements' tubular holder (3) in the direction of the pipe and so causing the cutting element (4) to cut a round hole in the pipe. The waste plastic cut out of the pipe is pushed into the tubular cutting element, from there into the tubular holder and is then discharged through the exit opening (9) in the upper part of the holder out in the direction of the handle. The appropriate position of the holder with respect to the handle is ensured by means of tabs (15) interacting with the exit opening (9) in the upper part of the holder.

D. On release of the hand-clasp pressure the spring (5) returns the cutting element and tubular holder back into its initial position.

Claims (1)

1. Claims (1). A hand punching tool, preferably for producing holes in plastic irrigation pipes or any other pipes made of flexible material comprises an elongated body provided with upper and lower jaws at its frontal extremity for mounting on the pipe to be punched, and a handle, pivotably mounted on the said body and carrying a tubular holder with a tubular cutting element, and the said lower jaw is adapted to carry interchageable sliding adaptors that embrace the pipes mounted in the body of the said tool, and the said lower jaw has a female recess mating with a male projection provided in the sliding adaptor, and the said recess and projection are directed along the longitudinal axis of the said body. (2). A hand punch as claimed in claim (1) in which the said tubular holder is provided with a spring as to ensure its return to the initial position after completion of the punching action, and the upper part of the said holder is formed with an exit interacting with appropriate guiding tabs provided on the underside of the handle as to eliminate its rotation. (3). A hand punch as claimed in claim (2) in which the rear part of the said body is provided with an open storage cavity for a spare tubular holder and/or cutting element. (4). A hand punch as claimed in claim (1) in which one of the said sliding adaptors is provided with a U-shaped inwardly facing surface interacting with the pipe to be punched and formed with a step as to ensure fixation of the tool with respect to the said pipe. (5). A hand punch as claimed in claim (1) in which the said female recess in the lower jaw of the body and male projection in the sliding adaptor have a T-shaped crossectional configuration. (6). A hand punch as claimed in claim (1) in which the said female recess in the lower jaw of the body and male projection in the sliding adaptor have a prismatic V-shaped, or any other suitably shaped, crossectional configuration. Appendix Page 1. Earlier hole puncher designs registered by me. Registered design no: 15885 in Israel, 22.12.89. Registered design no: 16673 in Israel, 4.7.90. Registered design no: DM/017821 International deposit at WIPO, 11.10.90. Registered design no: 17888 in Israel, 28.5.91. Registered design no: DM/021371 International deposit at WIPO, 9.12.91. Registered design no: 19064 in Israel, 4.2.92. Registered design no: 0259 in South Africa, 27.3.92. Registered design no: 115082 in Australia, 9.9.92. 5. Registered design application no: 20303 in Israel, 30.12.92.