Utility cutter

Abstract

An auto-retracting utility cutter includes a cutter body, a handle and an access door enabling top loading of replaceable blades into an slidable internal blade carriage. The blade carriage is actuated when sufficient force is applied to a linkage connected to the blade carriage which overcomes the inertia of the linkage but is resistant to casual squeezing and prevents injury from inadvertent deployment of the blade.

Claims

1. A utility cutter apparatus comprising: a body with a depressible handle; a blade carriage configured to house at least one blade, the blade carriage slidably movable within the body, the blade carriage actuable by the depressible handle via a linkage; the linkage including a pair of pivotably connected arms: a forward arm of the pair connected to the blade carriage and a rearward arm of the pair pivotably attached to the body; and, the linkage having a resting position where an inside angle between the pair of arms is less than 90 degrees and at least one tensioned active position where the inside angle between the pair of arms is greater than 90 degrees and the at least one blade is translated to an exposed position exterior to the body; a spring member having a first end to the rearward arm and a second end connected to the blade carriage bypassing the forward arm and configured to retract the carriage and the at least one blade from the exposed position; and, a linkage stop transversely disposed between the forward and rearward arms; a blade carriage access door disposed on a top side of the body, the blade carriage further comprising a flip up blade securing latch at the top side of the blade carriage and accessible directly beneath the blade carriage access door.

2. The utility cutter apparatus according to claim 1, the blade carriage access door configured to expose a blade re-fill slot disposed atop the blade carriage and adapted to receive replacement blades.

3. The utility cutter apparatus according to claim 1, the depressible handle requires an initial squeezing force of at least 1 kg required to depress the handle and move the blade carriage from the resting position to the active position.

4. The utility cutter apparatus according to claim 1, the blade configured to retract when force is relieved from the depressible handle.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

(1) FIG. 1 is a side elevation of an example utility cutter according to the present invention;

(2) FIG. 2 is a perspective view showing an exterior thereof;

(3) FIG. 3 is a perspective view showing an exterior of the body with a blade carriage access door opened;

(4) FIG. 4 is a perspective view showing an exterior of the body with a blade carriage access door opened and a blade securing latch in an opened position;

(5) FIG. 5 is a perspective view showing an exterior of the body with a blade carriage access door removed;

(6) FIG. 6 is a perspective view showing an interior of the body;

(7) FIG. 7 is a side view showing an interior of the body with blade carriage in retracted position;

(8) FIG. 8 is a side view showing an interior of the body with blade carriage in extended position;

(9) FIG. 9 is a perspective view of an interior of the example utility cutter.

REFERENCE LISTING OF THE NAMED ELEMENTS

(10) 100 utility knife 101 body 102 handle 102a handle pivot 103 anti-wear edge 104 blade carriage 105 carriage slide 106 blade carriage access door 107 top-loading aperture 108 blade securing latch 109 access door latch 110 blade 111 linkage 112a link arm 112b link arm 112c translatable joint 112d spring 113 rotatable pivot 114 linkage stop 116 carriage roller 117 eccentric slot 118 follower portion 119 spring anchor 120 blade slot

DEFINITIONS

(11) In the following detailed description, the singular terms “a”, “an”, and “the” include plural referents unless the context clearly indicates otherwise. Similarly, the word “or is intended to include “and” unless the context clearly indicates otherwise. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of this disclosure, suitable methods and materials are described below. It should be understood that the objects, features and aspects of any implementation/embodiment disclosed herein may be combined with any object, feature or aspect of any other implementation/embodiment without departing from the scope of the invention. The term “comprises” means “includes.” All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety for all purposes. In case of conflict, the present specification, including explanations of terms, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

(12) Referring generally to FIGS. 1-9 a safety utility cutter (100) includes a body (101) and a handle (102). Inside the body is a slidable blade carriage (104) actuated by depressing the handle (102) which is linked to the blade carriage by a follower portion (118) at the end of one of two pivotably connected arms (112a, 112b) forming a linkage (111). Medially disposed between the follower portion (118) connected to the blade carriage and a non-translatable but rotatable pivot (113) is a translatable joint (112c) where the two arms (112a, 112b) pivotably connect. When joint (112c) translates; e.g., moves laterally, by the application of force against the joint (112c) by squeezing handle (102), an inside angle between the two arms of the linkage (111) moves from an acute angle to an obtuse angle and thereby slides the blade carriage (104) and held blade (110) forward. A force between 0.8 kg and 1.5 kg caused by squeezing handle (102) and bearing on translatable joint (112c), is required to increase the inside angle between arms (112a, 112b). Typically the resting position of the linkage (111) exists when the handle is released. When the handle (102) is squeezed or depressed with a force, the inertia of the acute angular position is overcome and the linkage assumes an obtuse angle between the pivotable arms, thereby moving the blade carriage forward and exposes the blade for cutting purposes. When the handle (102) is released, a spring (112d), which in some implementations may be a coil type spring or an elastomeric band, is attached at one end to the blade carriage (104) and to the body interior at another, retracts the blade carriage and the held blade (110).

(13) FIG. 1 is a side view of an example cutter showing a body (101), that includes a blade assembly access door (106) and a handle (102). FIG. 2 is a perspective view of the example cutter.

(14) FIGS. 3 and 4 are perspective views showing the assembly access door (106) in an open position which exposes portions of the blade assembly carriage (104). FIG. 4 shows a blade securing latch in an up position which allows the top loading of replaceable blades (110) into the blade carriage (104).

(15) FIG. 5 is a perspective view of the example cutter (100) which shows an interior of the cutter body (101). FIG. 6 shows blade carriage (104) which is configured to slide between carriage slide (105) below the carriage, and roller (116) above the carriage which produces smooth linear movement. Linkage (111) includes arm (112a) which is secured to the body (101) at rotatable pivot (113) and a second arm (112b) which is secured to arm (112a) at translatable joint (112c), and second arm (112b) is connected to the blade carriage at follower (118) as shown. Blades (110) are removable from the carriage and insertable into the blade carriage (104) via top loading apertures (107), and the installed blades are secured by fold down latch (108) which may typically engage with the notches found in common utility blades.

(16) FIG. 7 is a side view showing an interior of the example cutter (100). When handle (102) is squeezed with a force of at least 0.8 kg, an inner portion of the handle bears against joint (112c) causing linkage (111) to translate as shown in (FIG. 8). Initially (FIG. 7) inside angle f between arms (112a, 112b) is less than 90 degrees. Squeezing/depressing the handle then causes the arms to move apart as joint (112c) slides along an inner surface of the handle causing arm (112b) to push the blade carriage (104) forward via follower (118) entrapped in eccentric slot (117). When the handle is released spring (112d) pulls the blade carriage (104) rearwardly and retracts the blade (110) back into the body. In this way the blade auto-retracts when the handle is not being depressed.

(17) FIG. 9 is a perspective view showing the interior workings of the example cutter (100) and a wear guard (103) that protects a portion of the body (101) below the cutting edge of blade (110) from excessive wear.

(18) It should be understood that the drawings and detailed description herein are to be regarded in an illustrative rather than a restrictive manner, and are not intended to be limiting to the particular implementations, forms and examples disclosed. Accordingly, it is intended that this disclosure encompass any further modifications, changes, rearrangements, substitutions, alternatives, design choices, and implementations as would be appreciated by those of ordinary skill in the art having benefit of this disclosure, and falling within the spirit and scope of the following claims.