Tube Cutter

Abstract

A tube cutter for use in cutting relatively soft tubing, such as plastic tubing and rubber hose, which is adapted to be operated in a user's hand to urge a cutting knife through a tube retained in the cutter by pivoting a blade carrier member relative to a base member. The carrier is biased toward the base member to urge the cutting edge of the blade into a protected relationship with the base to avoid injury to the user. The base includes a flat bottom surface permitting the tool to be also used by resting it on a flat surface and pressing down on the carrier with the user's hand.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to tube cutters and in particular to manually operated tube cutters.

2. Description of the Prior Art

In one form of tool for cutting soft tubular material, such as plastic tubing, rubber hose, etc., a knife blade is forced transversely through the tube. Different devices have been developed for effecting the forceful movement of the knife blade through the tube.

SUMMARY OF THE INVENTION

The present invention comprehends an improved tube cutter utilizing such a knife blade having improved means for manipulating the blade in the tube cutting operation. Further, the present invention comprehends such a tube cutter having improved means for effectively precluding injury to the user by the sharp cutting blade edge when the tool is not in use, such as when the tool is stored in a tool box.

More specifically, the invention comprehends providing such a tube cutter having a base having a flat bottom surface, means on the base for retaining a tube to be cut to extend parallel to the bottom surface, a cutter blade having a sharp leading cutting edge, a carrier, means mounting the carrier on the base for pivotal movement about an axial parallel to the bottom surface, and means connecting the cutter blade to the carrier to pass the cutting edge transversely through a tube retained by the retaining means as an incident of pivoting the carrier toward the base, the tube cutter being adapted selectively to be held in a user's hand with the fingers underlying the bottom surface and the thumb or palm of the user's hand engaging the carrier to urge the cutter blade through a tube retained by the retaining means as an incident of a manual squeezing action, or to have the base bottom surface rest on a horizontal support surface and have the carrier pressed down by a user's hand to urge the cutter blade through the tube retained by the retaining means.

The carrier may be provided with manipulating means for pivoting the carrier against the action of a spring arranged to bias the carrier toward the base thereby to open the tool for insertion of the tubing to be cut into holding relationship with the retaining means. The base member and retaining means may cooperatively define means for sheathing the sharp edge of the cutting blade as a result of the biasing action of the spring to a storage position of the tool.

The spring may include a mid-portion encircling the means pivotally mounting the carrier on the base and having opposite end portions egaging the base and carrier, respectively. The tool is arranged so that the spring may selectively be reversed to bias the carrier away from the base if desired.

BRIEF DESCRIPTION OF THE DRAWING

Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawing wherein:

FIG. 1 is a perspective view of a tube cutter embodying the invention with the user's hand and tube being cut being illustrated in dotted lines;

FIG. 2 is a fragmentary side elevation thereof with the carrier being shown in the "cut-start" position in dotted lines and the "cut-completed" position in full lines:

FIG. 3 is a front end view of the tube cutter;

FIG. 4 is a longitudinal section taken substantially along the line 4--4 of FIG. 2;

FIG. 5 is a transverse section taken substantially along the line 5--5 of FIG. 2; and

FIG. 6 is a transverse section taken substantially along the line 6--6 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the exemplary embodiment of the invention as disclosed in the drawing, a tube cutter generally designated 10 is shown to comprise a base 11 and a carrier 12 to which is secured a cutting blade 13 for use in cutting a tubular element T, such as a plastic tube, rubber hose, etc. Carrier 12 is pivotally mounted on base 11 by a suitable pivot means generally designated 14 and is biased to a storage position by a suitable spring means 15. In the storage position, the sharp cutting edge 16 of the cutting blade 13 is effectively sheathed, or covered, by reception thereof in a slotted portion 17 of a tube retaining means 18 carried on the base. Thus, when the tool is not in use, the carrier is biased suitably to prevent exposure of the cutting edge of the blade, effectively preventing injury to the user, such as where the tool is stored in a toolbox into which the user, at times, may insert his hand and attempt to locate a desired tool. As shown in FIG. 1 of the drawing, the tool is extremely compact with the base and carrier having a similar rectangular lateral configuration. The tool is extremely simple of operation while yet providing an improved, facilitated tube cutting operation.

More specifically, base 11 defines a lower flat surface 19 adapted to rest on a horizontal surface S, such as a table top. Alternatively, as shown in FIG. 1, the base is adapted to be supported by the user's fingers F turned thereunder with the user's thumb Th engaging the upper surface 20 of the carrier 12.

Upstanding from the base 11 is a pair of uprights 21. Carrier 12 includes a pair of outboard depending flanges 22 and a pivot pin 23 extends through flanges 22 and the uprights 21 to pivotally mount the carrier on the base for rotation about an axis parallel to the bottom flat surface 19 and to the axis of the tube T retained in the holding means 18. The spring 15, as shown in FIG. 6, includes a coiled mid-portion 24 turned about the pin 23 between the uprights 21, a first end portion 25 received in a downwardly opening notch 26 in a lug 27 depending from a rear end portion 41 of the carrier, and an opposite end portion 28 engaging the upper surface 29 at the rear of base 11. Thus, spring 15 effectively comprises a torsion spring biasing the carrier in a counterclockwise direction relative to the base, as seen in FIG. 2.

In pivoting the carrier to the open position shown in broken lines in FIG. 2, the user merely presses down on the rear extension 41 against the action of spring 15, thereby raising the blade sufficiently to permit the insertion of the tube T into the retaining means 18 under the tip 30 of the blade.

Carrier 12 is further provided with a depending boss 31 to which the blade 13 is secured by suitable means, such as screws 32. As shown in FIG. 3, the cutting edge 16 of the blade extends below the lower end 33 of the boss 31. The boss defines a downwardly opening recess 34 which accommodates the tube when the blade 13 is moved fully downwardly therethrough, as shown in FIG. 2.

The tube holding means 18, as seen in FIG. 1, includes a pair of upstanding bosses 35 spaced apart laterally of the base, i.e., parallel to the axis of pivot pin 23 and defining upwardly opening V-shaped recesses 36 for receiving the tube subjacent the cutting blade 13 when the carrier is pivoted to the open position of FIG. 2. As shown in FIG. 3, the lefthand boss 35 defines an upper surface 37 abutted by the lower surface 33 of the carrier boss 31 to limit the downward movement of the blade between the bosses 35 and thereby prevent damage to the sharp cutting edge 16 and tip 30 after the blade has cut fully through the tube. Thus, the blade edge is further effectively sheathed, or covered, by the bosses 35 in the storage arrangement of the tool to which the tool is brought by the action of spring 15 as discussed above.

The use of the tube cutter 10 is extremely simple. The user may alternatively effect a cutting operation by holding the tool in his hand or by placing the tool on a suitable horizontal surface, such as a table top. In the hand-held operation, the user merely pivots the carrier in a clockwise direction, as shown in FIG. 2, against the action of spring 15 by pressing down on the rearward extension 41 of the carrier, such as by the rear portion of his thumb, while supporting the base portion on his fingers. The tube to be cut is then inserted into the recesses 36 of the holding means to the desired position perpendicular to the flat plane of the cutting blade. The carrier is then forced in a counterclockwise direction by the user squeezing his hand with the force being applied by his thumb or palm of his hand directly over the blade 13 to firstly urge the tip 30 into the tube wall and then cause the sharp cutting edge to slice downwardly through the tube wall until the blade reaches the final "cut-completed" position of FIG. 2 wherein the cutting edge has passed fully through the tube. The portions of the tube may then be removed axially while retaining the sharp cutting edge in the enclosed condition thereby avoiding contact of the user's fingers with the sharp edge. The spring maintains the tool in the blade enclosing condition until such time as the user again pivots the carrier against the action of the spring to the "cut-start" position shown in dotted lines in FIG. 2 to effect a subsequent cutting operation.

Alternatively, the user may place the base on the table surface S and press down on the extension 41 to permit the tube to be inserted into the recess 36 below the blade. Thereupon the user may urge the palm of his hand against the portion of the carrier overlying the blade to press the blade through the tube to effect the desired cut. It should be noted that in each of the alternative uses of the tool, the force urging the blade through the tube is directed directly in line with the movement of the cutting edge.

For facilitated manipulation, the upper rear surface portion 44 of carrier 12 and rear portion 38 of lower surface 19 of base 11 may be serrated. Ashallow recess 39 may be provided in the upper front surface portion 40 of the carrier.

Tube cutter 10 is extremely simple of construction and of minimal size while yet providing the facilitated tube cutting operation discussed above, together with the improved safety feature of the enclosed cutting edge at all times except during the actual tube cutting operation. In the illustrative embodiment, the cutting tip defines an angle of approximately 120.degree. to provide an improved cutting action. The blade 13 is readily replaced as desired by the removal thereof permitted by screws 32.

If desired, the tube cutter may be rearranged to cause the carrier 12 to be biased away from the base 11 rather than biased toward the base 11 by a simple reversal of the spring 15. The carrier 12 may be provided with a second depending lug 42 spaced forwardly of lug 27 to be disposed forwardly of the vertical plane of the pivot pin 23. Lug 42 may be substantially similar to lug 27 being provided with a downwardly opening notch 43 corresponding to notch 26 of lug 27. As shown in FIG. 6, the lug extends only partially across the width of the carrier so that the end portions 25 and 28 of the spring 15 may be slipped past the lug 27 to the side thereof in turning the spring from the full line rearwardly extending position of FIG. 2 to the broken line forwardly extending position wherein the spring end portion 28 is received in the notch 43 of lug 42 and the opposite end portion 25 rests against the base surface 29. In this arrangement, the spring biases the carrier away from the base for facilitated insertion of the tube to be cut. Rearrangement of the spring may be readily effected by suitable conventional means such as a needle nose pliers and, thus, the tool is readily adapted for alternative biasing arrangment as desired by the user.

The foregoing disclosure of specific embodiments is illustrative of the broad inventive concepts comprehended by the invention.

Claims

We claim:

1. A cutter for cutting soft tubing comprising: a base having a flat bottom surface; means on the base for retaining a tube to be cut to extend parallel to said bottom surface; a cutter blade having a sharp leading cutting edge including a distal tip between opposite rectilinear receding slicing portions; a carrier having an upper surface; means mounting the carrier on the base for pivotal movement about an axial parallel to said bottom surface; means connecting the cutter blade to said carrier to pass said cutting edge transversely through a tube retained by said retaining means as an incident of pivoting said carrier toward said base, said tube cutter being adapted selectively to be held in a user's hand with the fingers underlying said bottom surface and the thumb engaging said carrier upper surface adjacent said cutter blade to urge the cutter blade tip firstly into the tube and then cause the cutting edge slicing portions to slice through a tube retained by said retaining means as an incident of a manual squeezing action, or to have said base bottom surface rest on a horizontal support surface and have said carrier pressed down by a user's hand adjacent said cutter blade to urge the cutter blade through the tube retained by said retaining means; and means for selectively biasing the carrier toward the base or away from the base as desired including a torsion spring having projecting end portions one of which engages the carrier and the other of which engages the base, means for mounting the spring coaxially of said mounting means axis with said projecting end portions being spaced from said mounting means axis to effect said selective biasing, and integral lug means for engaging a projecting end portion of the spring.

2. The tube cutter of claim 1 wherein means are associated with said lug means for retaining said projecting end of the spring.

3. A cutter for cutting soft tubing comprising: a base having a flat bottom surface; means on the base for retaining a tube to be cut to extend parallel to said bottom surface; a cutter blade having a sharp leading cutting edge including a distal tip between opposite rectilinear receding slicing portions; a carrier having an upper surface; means mounting the carrier on the base for pivotal movement about an axis parallel to said bottom surface; means connecting the cutter blade to said carrier to pass said cutting edge transversely through a tube retained by said retaining means as an incident of pivoting said carrier toward said base, said tube cutter being adapted selectively to be held in a user's hand with the fingers underlying said bottom surface and the thumb engaging said carrier upper surface adjacent said cutter blade to urge the cutter blade tip firstly into the tube and then cause the cutting edge slicing portions to slice through a tube retained by said means as an incident of a manual squeezing action, or to have said base bottom surface rest on a horizontal support surface and have said carrier pressed down by a user's hand adjacent said cutter blade to urge the cutter blade through the tube retained by said retaining means; and means for selectively biasing the carrier toward the base or away from the base as desired including a torsion spring having projecting end portions one of which engages the carrier and the other of which engages the base, means for mounting the spring coaxially of said mounting means axis with said projecting end portions being spaced from said mounting means axis to effect said selective biasing, and integral lug means defining notch means for engaging and removably retaining a projecting end portion of the spring.