EP0100377B1

EP0100377B1 - A pocket-tool, pocket-knife or similarly retractable tools

Info

Publication number: EP0100377B1
Application number: EP82200982A
Authority: EP
Inventors: Bram Jan Voslamber
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-07-30
Filing date: 1982-07-30
Publication date: 1987-09-30
Also published as: EP0100377A1; DE3277404D1; ATE29978T1

Abstract

Tool elements (1) rotating in and out of the tool holder (4) around a cylinder (2) of such dimensions and construction that it has a strength similar to the tool elements, The aperture of the cylinder can fit, for instance, a forefinger, and, together with the flanges (19) of the cylinder, it will provide the user of the pocket tool with a firm grip. The greatly increased width of the tool element around the cylinder provides for a locking device (3) consisting of a spring-loaded cath (9) and a recess arrangement (9, 10) at the rim of the tool element so as to hold the opened tool element securely when in use. The locking device can be released by pulling a catch, or with the aid of a lever (6, 7).

Description

The invention is concerned with a folding pocket tool including a set comprised of one or more tool elements, such as knife blades, said set being enclosed between two parallel cover-plates defining a handle of said pocket tool shaped to provide a firm grip for a user's hand, each tool element being individually pivotable relative to said handle about a pivot cylinder, whereby each tool element has a pivot end fully encircling a bore for close-fitting location around said pivot cylinder,

such a pocket tool is further provided with locking means for each tool element relative to the handle, comprising a latch maintainable in engagement respectively with a notch and/or a depression in the pivot end of the tool element by resilient means for locking the tool element in an extended position and for retaining it in a folded position, whereby
separating plates are preferably interposed between the tool elements of said set, and interconnected, together with said cover plates and the fixed part of said locking means, to comprise said handle, by fastening means located in bores so positioned as not to obstruct folding of said tool elements.

A pocket tool of this type is known from the U.S. Patent Specification 4,124,939. However, in order to provide a safe, reliable and sturdy foldable pocket tool, both the tool elements and their pivot structure and locking arrangement should be of substantially equal strength to resist the prevailing different loadings exertable with the tool elements which may be fitted to the pocket tool. The pivot structure according to said U.S. Patent Specification is weak compared to the size of the tool and to the size of the grip. However, a sturdy latch and notch combination to lock the tool in the extended working position is present. It is surprising that even the sturdiest foldable pocket tools known from the prior art are weak with regard to the pivot structure and many of them also with regard to weak and/or unsafe latching mechanisms. Many do not even have a reliable locking mechanism for the working position of the tool but must rely on a spring-loaded retaining arrangement. Especially bending forces acting in a plane perpendicular to the plane in which the tool pivots will give rise to distortion and damage of the pivot structure due to the forces, to which the pivot structure can be subjected. Usually the tool itself can withstand considerable higher bending forces than the pivot structure.
The invention aims to provide a sturdy and reliable foldable pocket tool in which all parts are of substantially the same resistance to the maximum load exertable by a user's hand through the grip on each type of tool which is fitted or fittable to the tool. According to the invention the above- described foldable pocket tool is characterised in that

- the outer extent of the pivot end of each tool element is defined substantially by a circular arc centered on the bore in said pivot end which locates around the pivot cylinder, said circular arc being of substantially the same diameter for each tool element,
- the pivot cylinder has at each end radially outwardly extending flange-like members abutting a flat outer surface of the respective cover plates and having an outer diameter substantially equal to the mean outer diameter of the pivot ends of the tool elements,
- whereby the pivot cylinder with its flange-like members offers resistance to stress developed during use of a tool element at least equivalent to the resistance offered by the pivot end of the tool element along its operational plane of weakness,

Compared to all known foldable pocket tools the sturdy pivot cylinder with its flanges provides a greatly increased width at the pivot end. When the pocket tool is of a larger type, according to a preferred embodiment, the pivot cylinder may have a concentric bore sized to allow insertion of a finger for improved grip of the pocket tool.
Since the highest loads on the pocket tool are concentrated near the pivot region, the overall width of the pocket tool may be substantially larger at its pivot end than over the central part of the pocket tool which serves as handle for the user. This provides for a still safer grip of the tool by the user's hand.
In itself a pocket tool with a hollow cylindrical pivot arrangement is known from the U.S. Patent Specification 2,798,290. It even has small flanges at its end. However, it is clear that the cylinder and its flanges in this case are of very modest size and strength.
In the description of the accompanying figures below structural details of preferred embodiments of the pivot structure are revealed. One preferred embodiment wherein the pivot cylinder consists of two cylinders closely fitting one into the other, mutually fastened together by screw threads, is such that each cylinder carries one of said flanges, whereby the outer cylinder extends from the flange at one end to its other end over a distance which, when assembled, corresponds substantially to the combined width of the set of tool elements, of any separating plates present and of both cover plates. In doing so, certain tool elements may easily be replaced by others or interchanged for other types. Without complicating the pocket tool by adding devices, it has become more effective since it can be adapted to all kinds of operations.
Since the pocket tool mentioned above as having a reliable strong and resistant pivot structure to withstand an operational load from virtually any type of tool element is foldable, it can only be reliable if the locking mechanism is as reliable and strong as the tool elements and the pivot structure. Therefore a foldable pocket tool with one or more tool elements is preferably further characterised in that there is only one single latch extending over the combined width of the tool element, such as to be engageable with the notches of every tool element and/or retaining the hold positions at the end of the depression of every tool element, said latch extending parallel to the axis of the pivot cylinder, having a width at least equal to the width of the packaged set consisting of all tool elements and of any separating plates present. Since the position of the latch and cooperating notches is at the outer circumference of the pivot end of the pocket tool, greatly increased forces can be resisted, compared to all known structures where the latch-notch combination is located much nearer to the centerline of the pivot.
Further preferred embodiments of the latch-and notch arrangement will be discussed below in connection with the figures.
It will be evident to the skilled man that sizes and dimensions of the locking mechanism and the pivot structure will depend on the field of application for which the pocket tool is designed.
The invention is further detailed below in the description of the figures illustrating preferred embodiments.
The figures 1, 2 and 3 show a pocket-tool in closed position comprising essentially a tool element, a cylinder 2 around which the tool element 1 can rotate, a springloaded locking device 3 securing the tool element 1, coverplates 4, separating plates 5 and lifting handles 6, 7 and 8.
In accordance with the invention, the tool-element 1 is firmly placed with flat surfaces between flat mating surfaces of separating plates 5 or coverplates 4. Likewise the inner surfaces of the flanges 19 of cylinder 2 rest firmly and with flat surfaces against mating surfaces of the cover- plates 4.
The springloaded locking device 3 keeps the tool-element 1 locked when latch 9 falls in recess or notch 10, which can be achieved by rotating tool-element 1 around cylinder 2.
Lifting the locking device 3 can be accomplished in various ways, in figure 1 for instance a recess 12 is provided which can have various shapes and can also be a gap. By pulling disengagement of latch 9 is achieved. Latch 9 moves into depression 13 where tool-element 1 is nearing its rest position as is shown in figure 1 and 2. This retains the tool-element 1 in its folded or rest position.
In figure 2 lifting levers 6 and 7 are shown as variations for lifting the spring-loaded locking device 3 when more force is required than can be reasonably expected from a thumbnail. Lever 6 pivots around pin 15 which runs through the separating plates 5 and coverplates 4. Separating plates 5 each have a recess 16 to accommodate lever 6. On lever 6 a stud 17 is provided resting with one side against the springloaded arm of locking device 3. When lifting and rotating lever 6, stud 17 rotates and lifts locking device 3 whereby face 18 becomes engaged.
Lever 7 is pivotable around pin 15 in the same chamber that gives accommodation to the tool-element 1 thereby lifting locking device 3.
A cross-section of the cylinder 2 is given in section B-B of figure 2 showing an alternative solution to the locking of the tool-elements 1 and plates 4 and 5; instead for instance of direct riveting, a ring 20 is slipped over the unfinished end of the cylinder till it meets a stepwise increase in the diameter at the location of end plate 4 so that ring 20 is locked in the right position when the cylinder extension is rolled into a flange. The advantage of this variation is that the contact force of ring 20 onto coverplate 4 by which the tool-elements 1 are locked can be well controlled. Ring 20 can have a circular shape or any other shape to improve its strength.
Figure 3 shows a locking device whereby latch 9 extends over all tool-elements 1, serving all tool-elements 1 simultaneously. For lifting the locking device 3 any lifting device can be used. Shown is a handle 8 rotating around cylinder 2. Rim 21 in contact with latch 9 is curved such that a larger radius lifts the locking device 3 when handle 8 is rotated. For passing handle 8, locking device 3 is provided with a window 22. The fixed end of locking device 3 for instance has recesses 23 for accommodating separating plates 5. Holes 24 for instance indicate a fastening means for cover- plates 4, separating plates 5 and the locking device(s) 3.
Two more possible means of constructing the cylinder 2 are illustrated. In detail A a double cylinder consisting of an inner cylinder 25 and an outer cylinder 26 are screwed in each other with matching thread so that the tool-elements 1, separating plates 5 and coverplates 4 are locked together as tight as required between the surfaces 27 and 28. The position of the two cylinders 25 and 26 can be secured for instance with a spring 29 provided in one of the coverplates with a butt 30 that fits into a recess in the flange of one of the cylinders 25 and 26 while the other cylinder flange is secured for instance with a fixed pin. This construction allows replacement of tool-elements 1 and cleaning.
Another method of securing the two cylinders together is by rolling the inner cylinder end into a flange 31 fitting a recess in the flange of the outer cylinder 26 for instance as shown in detail B.

Claims

1. A folding pocket tool including a set comprised of one or more tool elements (1), such as knife blades, said set being enclosed between two parallel cover-plates (4) defining a handle of said pocket tool shaped to provide a firm grip for a user's hand, each tool element being individually pivotable relative to said handle about a pivot cylinder (2), whereby each tool element has a pivot end fully encircling a bore for close-fitting location around said pivot cylinder (2),

-the pocket tool being provided with locking means (3, 9,10,13) for each tool element relative to the handle, comprising a latch (9) maintainable in engagement respectively with a notch (10) and/ or a depression (13) in the pivot end of the tool element (1) by resilient means (3) for locking the tool element in an extended position and for retaining it in a folded position,

- separating plates (5) being preferably interposed between the tool elements (1) of said set, and interconnected, together with said cover plates (4) and the fixed part of said locking means, to comprise said handle, by fastening means located in bores (24) so positioned as not to obstruct folding of said tool elements (1), characterised in that

- the outer extent of the pivot end of each tool element (1) is defined substantially by a circular arc centred on the bore in said pivot end which locates around the pivot cylinder (2), said circular arc being of substantially the same diameter for each tool element,

- the pivot cylinder (2) has at each end radially outwardly extending flange-like members (19; 27, 28; 31) abutting a flat outer surface of the respective cover plates (4) and having an outer diameter substantially equal to the mean outer diameter of the pivot ends of the tool elements (1),

-whereby the pivot cylinder (2; 25, 26, 31) with its flange-like members (19) offers resistance to stress developed during use of a tool element at least equivalent to the resistance offered by the pivot end of the tool element (1) along its operational plane of weakness,

which resistance is determined by the resistance of the tool element of said folding pocket tool at its zone of application to the load exerted by a user's hand when gripping said handle.

2. Pocket tool according to claim 1, characterised in that
the pivot cylinder (2) has a concentric bore sized to allow insertion of a finger for improved grip of the pocket tool.

3. Pocket tool according to claim 1 or 2, characterised in that
the overall width of the pocket tool at its pivot end perpendicular to the pivot centerline is substantially larger than the width of the central part of the pocket tool which serves as handle for the user.

4. Pocket tool according to claim 1, 2 or 3, characterised in that
the pivot cylinder has an integral flange (19) at one end whereas at the other end a concentric cylindrical portion of reduced outer diameter forms a shoulder with stepwise change in diameter, the distance between said shoulder and the integral flange being substantially equal to the combined width of the set of tool elements (1), of any separating plates (5) present and of both coverplates (4), whereby a closing ring (20) abuts against said shoulder when located around the portion of reduced outer diameter, said closing ring (20) having an outer diameter substantially equal to the diameter of the flange (19), and in which the part of the pivot cylinder (2) extending past the closing ring is rolled out by plastic deformation to lock the closing ring firmly to the pivot cylinder.

5. Pocket tool according to any one of claims 1 to 3, wherein the pivot cylinder (2) consists of two cylinders (25, 26) closely fitting one into the other, mutually fastened together, by screw-threads or by plastic deformation such as resulting from rolling, characterised in that
each cylinder carries one of said flanges (27; 28), whereby the outer cylinder (26) extends from the flange at one end to its other end over a distance which, when assembled, corresponds substantially to the combined width of the set of tool elements (1), of any separating plates (5) present and of both cover-plates (4).

6. Pocket tool according to any one of the preceding claims, in which the pocket tool has one or more tool elements, characterised in that
the latch (9) extends over the combined width of the tool elements (1), so as to be engageable with the notches (10) of every tool element, and/ or retains the hold-position at the end of the depression (13) of every tool element, said latch (9) extending parallel to the axis of the pivot cylinder (2), having a width at least equal to the width of the packaged set consisting of all tool elements (1) and of any separating plates (5) present.

7. Pocket tool according to any one of the preceding claims, characterised in that
when the tool elements are in the 16cked position the free end of the resilient means (3) of the latch (9) is spaced from the central grip nearest the pivot end to form at least on one side a gap (12) permitting insertion of a finger nail preferably through a small recess in the cover-plate(s) (4) and/or in the latch carrier (3), to directly unlock the locking means (Fig. 1).

8. Pocket tool according to any one of the preceding claims, in which there is a hand-operable lever (6, 7, 8) pivoted in the handle (4), having a protruding part (17, 21) positioned close to the resilient means (3) of the latch (9) so that pivoting of the lever to a position outside the handle (4) moves the protruding part (17, 21) to engage and displace the resilient means (3) to a position in which the latch (9) releases the tool elements.