Knife blade and handle

[57] ABSTRACT

A flat sheet steel knife blade is provided with three equidistantly spaced openings. Two of these openings permit the blade to be used in one, or a reversed position, in a holder made up of two separable mating parts. These handle parts need not be separated in order to remove the blade for reversing or replacement. A leaf spring mounted in the holder has projecting pins which are adapted to enter the two blade openings in the blade, said leaf spring being manually movable between a blade clamping and a blade release position.

Claims, 4 Drawing Figures

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PATENTEDMOV 51974

3.845,554

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3.845.554

KNIFE BLADE AND HANDLE

SUMMARY OF THE INVENTION

This invention relates generally to utility knife blades and holders therefore, and deals more particularly with a utility knife of the type used by craftsman or tradesman to sever and install various types of floor coverings, wall materials such as sheet rock and other sheet materials.

A primary object of the present invention is to provide an improved knife blade and holder which will permit the blade to be removed and reversed or replaced without separating the mating handle parts or halves.

Another object of the present invention is to provide a holder which will permit a plurality of knife blades to be stored for easy access, again without separating the handle halves.

Still another object of the present invention is to provide an improved knife blade suitable for use in a holder of the foregoing type, which blade can be readily reversed to permit the use of opposite cutting edges defined thereon.

A still further object of the present invention is to provide an improved knife blade and holder which holder has an attractive low profile appearance, is of a simplified yet durable construction, and which is economical to manufacture and assemble.

The essential elements of the present invention comprise two mating handle parts, or halves, one of which has an internal blade clamping compartment, and the other of which parts has an internal receptacle for receiving a blade engaging portion of a leaf type spring. The leaf spring is adapted to have its blade engaging portion overlie the compartment in which the blade is adapted to be retained, and manual button means is provided external to the mating handle parts for moving the spring from its clamping to its release position. Biasing means is provided for urging the blade engaging spring portion toward its blade clamping position. Preferably, the spring includes projecting pins which are adapted to be received in two of three openings provided for this purpose in the blade, and as such, the blade can be conveniently removed and reversed or replaced without the necessity for separating the mating handle parts or halves.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. i is a plan view of a holder incorporating the present invention together with an associated blade.

FIG. 2 is a plan view of the lower handle part which mates with the upper handle part of FIG. 1 to provide the holder for the blade.

FIG. 3 is a vertical sectional view taken along the line 3-3 of FIG. 1.

FIG. 4 is a detailed view of a portion of the handle of FIG. 3 with the leaf spring being shown in its deformed position suitable for release of the blade.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Turning now to the drawing in greater detail, FIGS. 1 and 2 show the mating handle parts or halves 10 and 12 respectively, which parts cooperate to define a grip portion adapted to be held in the hand of the user, and a somewhat smaller nose portion adapted to receive a blade B. These mating handle parts 10 and 12 are separably joined one to the other, preferably by means of a pair of mounting screws, 14, 14. While one such screw might be used for this purpose, two such screws 5 are preferably employed, and at the end of the grip portion of these handle parts a projecting pin 16 on the upper part 10 is adapted to be received at a suitable mating recess defined for it in the lower part 12 as best shown in FIG. 3.

¹⁰ These mating handle parts 10 and 12 can be seen from FIG. 3 to cooperate with one another to define a blade storage compartment 18 in which a plurality of blades B, B are adapted to be stored for future use. Biasing means is provided in this storage compartment 18 ¹⁵ for urging all of these blades toward a finger opening 20, and preferably said biasing means comprises a generally U-shaped spring element 22 which carries a blade backing plate 24 somewhat larger than the size of the finger opening 20 in order to avoid loss of the U^υ shaped spring element 22 when all of the blades B, B are exhausted. Each of the blades B, B is fabricated from sheet steel stock, and has a regular shape so that the uppermost blade B in FIG. 3 can be moved or with₂₅ drawn rearwardly through a slot 27 provided for this purpose in the upper handle part 10. As so constructed and arranged, the user of the improved blade holder described and claimed herein can conveniently remove one blade from the storage compartment without the 30 necessity for separating the handle parts 10 and 12. This advantage to the present holder construction will be even more apparent in connection with the description of the blade retaining nose portion (to be described) which portion is so designed as to permit re35 moval and replacement of the active blade, again without the necessity for separating the handle parts.

As best shown in FIG. 3, the lower handle part 12 includes a blade clamping compartment 30 in which a blade B is adapted to be securely held by a leaf spring 40 32, and its associated pins 34 and 36. The blade clamping compartment 30 is preferably of rectangular contour, as best shown in FIG. 2, so as to accommodate blades of various regular shape. Preferably, however, the blade B is generally trapezoidal in shape and in45 eludes three openings 34α, 36α and 34b. The cutting edge or tip of the blade B carries reference numeral 38 but it will be apparent that the oppositely arranged cutting edge 40 is symmetrically configured so as to permit removal and reversing of the blade B. Still with refer⁵⁰ ence to the construction of the blade B, it is noted that although the longer edge of the trapezoidally shaped blade is shown as relieved to define a cutting edge 39, it will be apparent that the shorter symmetrically arranged edges 37 and 41 might instead be relieved in the ⁵⁵ fabrication of the blade to define symmetrically arranged cutting edges at 37 and 41. Other blade shaped might be fabricated for use in a holder of the present invention, and the essential features of a blade constructed according to the present invention will be de^υ fined herein below.

Still with reference to FIG. 3, the upper handle part 10 defines an internal spring receptacle 50 for receiving the blade engaging portion of the leaf spring 32 ₆₅ when said leaf spring is deformed from the FIG. 3, or normal position, to the FIG. 4, or blade release position. In the release position of FIG. 4, it will be apparent that the blade B can be manually withdrawn from

3,845,554 the blade clamping compartment 30 without the necessity for separating the handle parts 10 and 12.

Turning now to a more detailed description of the operation for the leaf spring 32, the inner portion of said spring 32 defines a manually operated means in the form of a button 60, which button projects through an opening provided for this purpose in the upper handle part 10. The button 60 is conveniently accessible for operation by the thumb of the user. The leaf spring 32 preferably has a shape such that manually depressing the button 60 as shown in FIG. 4 causes the leaf spring 32 to assume a shape whereby the pins 34 and 36 are withdrawn from the openings 34α and 36α in the blade B. The dimension of the internal spring receptacle 50 in the handle part 10 is such that these pins 34 and 36 will not interfere with the blade B during blade removal (FIG. 4) for reversing or replacement. Although not essential to the present invention, the lower handle part 12 may include receptacles 46 and 48 for the pins 34 and 36 respectively in order to securely anchor the blade B in place when the spring 32 is in its spring retaining position as shown in FIG. 3.

Still with reference to the spring 32, it will be apparent from a comparison of FIGS. 3 and 4 that the outer or blade engaging portion of this leaf spring 32 cooperates with the inner button portion thereof to define an intermediate portion which serves as a fulcrum acting against the lower handle part 12 to achieve the necessary motion described above. Furthermore, a land 52 defined for this purpose in the upper handle part 10 assures that the leaf spring 32 is properly restrained for achieving the motion defined for in FIGS. 3 and 4 of the drawing. As mentioned above, biasing means is provided for urging the spring 32 toward its blade clamping position, and preferably said means comprises a small coil spring 54 which exerts a light spring force between the lower handle part 12 and the inner portion of the leaf spring 32. However, it should perhaps be noted that the function of this spring 54 might be conveniently provided for as a result of redesigning the inner portion of the leaf spring 32, or by utilizing equivalent biasing means such as, for example, a torsion spring provided in the space adjacent the upper surface of the inner portion of the leaf spring 32, i.e., opposite the coil spring 54, or by providing a tension spring in this area. It should perhaps be noted that very little biasing force is required to urge the spring 32 toward its FIG. 3 position for clamping the blade B in its associated receptacle 30. The important function of the leaf spring 32 resides in said spring’s capability of assuming the configuration shown in FIG. 4 whereby the blade B can be conveniently removed from its receptacle, and whereby the pins 34,36 associated with the leaf spring 32 are raised out of the openings in the blade to allow said blade to be so removed.

Finally, and still with reference to the leaf spring 32, said spring has a non-deformed configuration of generally flat slightly Z-shape, the inner portion thereof defining said Z-shape as indicated generally at 62 in FIG. 3. This Z-shaped inner portion 62 of the leaf spring 32 is arranged in a relatively narrow recess 64 defined in the upper handle portion 10, and the lateral dimension of this recess is so chosen that the spring 32 is maintained in the orientation shown for it in FIG. 2. Thus, the lateral dimension of the recess 54 is somewhat exaggerated in FIG. 2 for clarity, but it will be apparent that this recess, together with the opening for the but ton 60, assures that the leaf spring 32 remains in position during removal of a blade B. The corresponding recess 66 in the lower handle part 12 may be of a corresponding dimension, but the chief function of this recess 66 is to provide space for the inner portion 62 of the leaf spring 32 when the spring is moved from and to its normal blade clamping position to and from its blade release position.