U.S. patent number 3,927,473 [Application Number 05/461,887] was granted by the patent office on 1975-12-23 for replaceable blade knife.
This patent grant is currently assigned to Philip Morris Incorporated. Invention is credited to Paul A. Braginetz.
United States Patent |
3,927,473 |
Braginetz |
December 23, 1975 |
Replaceable blade knife
Abstract
A knife with replaceable blades embodying a handle in which a
working blade is clamped in a holder which in turn is releasably
clamped in an outer end of the handle, the handle having a cavity
in which is pivotally mounted a tray for new blades, which are
supported therein in a manner rendering the individual blades
readily removable, the blade holder being mounted on a clamping
screw threaded pivot bolt enabling the holder and its blade upon
release of the clamping bolt to be rotated when not in use into a
blade protected position within the handle and being arranged in
such position to lock the blade tray from being moved from within
the handle.
Inventors: |
Braginetz; Paul A. (Staunton,
VA) |
Assignee: |
Philip Morris Incorporated (New
York, NY)
|
Family
ID: |
23834347 |
Appl.
No.: |
05/461,887 |
Filed: |
April 18, 1974 |
Current U.S.
Class: |
30/125; 30/162;
30/331; D8/98; 30/164 |
Current CPC
Class: |
B26B
5/00 (20130101) |
Current International
Class: |
B26B
5/00 (20060101); B26B 005/00 () |
Field of
Search: |
;30/2,125,151,155,156,161,164,320,321,330,331 ;145/62,64 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Smith; Al Lawrence
Assistant Examiner: Watson; Robert C.
Attorney, Agent or Firm: Watson Leavenworth Kelton &
Taggart
Claims
I claim:
1. A knife having an elongated handle with opposed side walls and a
cavity therebetween and a blade removably mounted at one end of the
handle for replacement by a new blade, a tray for new blades
normally positioned within said cavity and mounted for movement
into a closed position within said cavity and outwardly thereof
through an opening in an edge of the handle for removal of a blade,
said tray having a supporting platform for a stack of blades, a rib
extending upwardly from said surface transversely of the direction
of said movement adapted to receive thereover the slots of a stack
of slotted blades, said rib having end lug portions extending above
the stack of blades with a depression between the lugs, and the
corresponding handle wall having a downwardly projecting fixed rib
extending into said depression in closed position of the tray
transversely of said tray rib to maintain the top blade below the
top of said lug portions.
2. A knife in accordance with claim 1 in which the tray is
elongated and pivoted at one end and said tray rib extends
longitudinally thereof and said fixed rib extends transversely
thereof in said depression in closed position of the tray.
3. A knife in accordance with claim 1 in which there is a detent
means spaced from said pivotal end of the tray for releasably
holding the tray in closed position.
4. A knife comprising a handle, a blade holder, a tray for new
blades, said tray having a pivotal mounting within the handle about
which it may be swung outwardly for exposure of the blades, means
for mounting the blade holder in an outer end of the handle, said
holder being selectively movable on said mounting means to an outer
working position, or to an inner blade edge protective position
within the handle, and interlocking means between the holder in its
inner position and the blade tray to prevent the tray from being
swung outwardly from its position in the handle.
5. A knife in accordance with claim 4 in which the mounting means
for said blade holder comprises a pivot about which the blade
holder is rotatable to its different positions.
6. A knife in accordance with claim 5 in which said pivot comprises
a screw threaded bolt means adjustable to clamp the blade holder in
its selected positions.
7. A knife in accordance with claim 6 in which the blade holder
comprises a pair of opposed halves between which the blade is
located and clamped in place by the clamping of the holder in the
handle.
8. In a replaceable blade knife having a handle and a tray for
supporting a stack of new blades, means for mounting the tray in a
cavity in the handle for movement outwardly from the cavity to
expose the blades, said tray having a top surface with raised rails
for supporting thereon the stack of blades elevated from the tray
surface, said rails including a longitudinally extending rail
section and a cross rail section, the latter spaced inwardly from
an end of the blade stack about which one or more blades comprising
the stack may be rocked by cantilever action by finger pressure on
said end.
Description
BACKGROUND OF THE INVENTION
The invention is concerned with a type of knife adapted for such
purposes as cutting carpets or linoleum or many other uses, the
knife comprising a handle adapted to hold a blade replaceable by a
new blade when through use or other conditions the blade becomes
worn or damaged. Many varied designs for this general type of knife
have heretofore been used or proposed such as that which is the
subject of U.S. Pat. No. 3,577,637 of the present inventor; and
reference may be made also to the U.S. Pat. No. 3,593,417. Commonly
the handle has a cavity for storing a supply of new blades. In some
cases access to the new blades is through separation of the handle
halves but in the case of the above noted patents the individual
blades are removable through means of a pivoted tray. In the case
of the U.S. Pat. No. 3,577,637 the tray is adapted to remove a
single blade from the stack and in the case of the U.S. Pat. No.
3,593,417 the entire stack of blades is mounted on the tray and is
adapted to be swung outwardly for removal of a blade. Detent means
are provided in each case for releasably holding the tray within
the handle.
The blade in the general type of knife here concerned is held at
the outer end of the handle when the knife is in use but commonly
means are provided for moving the blade into a retracted protected
position. Many and varied holding means are provided for
positioning the blade in either its operative location or retracted
protected location a common form comprising a slidable carrier on
which the blade is mounted.
THE PRESENT INVENTION
The main features and physical elements of the present invention
comprise an elongated handle with the working blade rigidly clamped
in a holder positioned at the outer end of the handle, the holder
having a pair of halves in which the blade is clamped with an
exposed cutting edge. A single screw threaded bolt rigidly clamps
the holder in a slot between fingers at the outer end of the
handle. The blades are double edge for economy and mounted in the
holder and extending over the inoperative edge is a protective
shield which likewise is clamped in the blade holder by the single
screw part just mentioned. By loosening the screw the blade holder
may be rotated to position the normally exposed cutting edge in a
protected location interiorly of the handle.
The means for maintaining a supply of new blades embodies a blade
tray pivotably mounted within a cavity in the handle, and
associated with the tray is a detent means positioned entirely
interiorly of the handle when the tray is in closed position, the
detent means being releasable by engagement of a finger piece
adjacent the detent but exposed exteriorly of the handle. The stack
of blades which are of the type having a longitudinal central slot
are positioned over a rib on the tray and associated therewith is
an arrangement whereby the blades are maintained below a certain
level so as not to interfere with the movement of the tray to its
outer exposed position for removal of the top blade.
Other physical elements and features comprising the combination
will be made apparent by consideration of a representative
embodiment of the invention. Accordingly, in connection with the
description reference should be made to the accompanying drawings
in which:
FIG. 1 is a top plan view of the assembled knife showing in broken
lines the blade tray swung to an outer exposed position.
FIG. 2 is an edge plan view of the assembled razor.
FIG. 3 is a cross-sectional view taken on the plane 3--3 of FIG. 1,
the knife accordingly being inverted from the normal position shown
in FIG. 1.
FIG. 4 is an end view taken from the position indicated by the
arrows 4--4 in FIG. 1.
FIG. 5 is a cross-sectional view taken on the plane 5--5 of FIG.
1.
FIG. 6 is an end view taken from the position indicated by the
arrows 6--6 in FIG. 1.
FIG. 7 is a plan view of the blade holder as initially formed in
open position.
FIG. 8 is a cross-sectional view taken on the plane 8--8 of FIG.
7.
FIG. 9 is a cross-sectional view taken on the plane 9--9 of FIG.
7.
FIG. 10 is a plan view of the blade holder of FIG. 8 to 9 with the
halves of the holder folded over and a blade positioned between the
halves.
FIG. 11 is a plan view of the blade tray.
FIG. 12 is a cross-sectional view taken on the irregular section
indicated by 12--12 in FIG. 11.
FIG. 13 is a fragmentary view corresponding to FIG. 1 but with the
blade holder rotated to its blade protective position.
FIG. 14 is a fragmentary cross-sectional view taken on the plane
14--14 of FIG. 11 but illustrating the blade stack tipped by finger
pressure to render the individual blades readily removable.
The knife embodies a main casing having two side walls comprising
opposed complemental handle halves, one of which will be referred
to as the right half 15 and the other as left half 16. As shown
clearly in the cross-sectional view of FIG. 3 the halves are held
together by a pair of screws 17 and 18, the screw 17 being threaded
into a boss 19 extending from the left half 16 into the depression
20 in the right half 15, the left half also has a blank stud or
post 21 projecting into a recess 22 in the right half. The opposed
faces of the handle halves are hollowed out to form a slot or
cavity with an edge access opening 23 as indicated in FIGS. 4 and
5. Pivotably mounted on the boss 19 is a blade tray 25 in which is
positioned normally a stack of blades 26. Normally clamped between
the outer end of the handle is a blade holder or retainer 27 in
which is releasably clamped a blade 26a. The blade holder, as
initially formed is shown in the plan view of FIG. 7 and in
cross-section in FIGS. 8 and 9. The holder is composed of a
suitable plastic material such as polypropylene and is cast in
extended condition as shown in FIGS. 7 and 8 with the halves
connected by a portion 30 of reduced thickness and flexible to form
what is sometimes referred to as a living hinge. When folded into
the form shown in, for example, FIG. 10 with an intervening blade
26a, lugs on one half project through the blade into recesses in
the opposed half, the blade in the present case having a central
slot 31 through which the lugs extend. The lugs comprise an
elongated rib 32 extending through the blade slot 31 into a recess
33 in the opposed half and similarly a lug 34 extending into a
recess 33 in the opposed holder half, the lugs determining the
transverse position of the blade and the lug 34 acting as a blade
stop in the direction toward the right and shoulders 35 and 36
limiting opposite movement of the blade toward the left. The blade
retainer is clamped between the two handle halves by the screw bolt
18 as shown in FIG. 3 which also serves to clamp the blade 26a in
the retainer. The screw bolt in the present case comprises a screw
countersunk in the handle half 15 and threaded into the other
handle half 16. A split tube 40 serves as a shield extending over
the upper edge of the blade and preferably slightly beyond the
outer end. The protective sleeve is clamped between the two halves
of the blade retainer 27 by the screw 18. In normal use the
operator engages a thumb against an upper finger piece comprising a
projection 41 of the blade retainer which is preferably serrated as
indicated at 42 and the shield 40 protects the operator in the
event his hand or a finger should accidently extend beyond the
finger piece 41.
The blade tray 25, pivoted on the boss 19, has an outer forked end
50 including spaced fingers 50a. It has a serrated upper edge 51
for engagement normally by the thumb of the operator. The handle
halves 15 and 16 have an arc-shaped depression 52 to allow the
finger piece 50 to be positioned below the upper edge of the handle
but readily engageable by the thumb or finger of the operator. As
viewed from the right end in the drawings, the outer end of the
tray has the shape of an inverted U formed by the pair of spaced
fingers 50a with an intervening slot 55. Each of the fingers has a
slot 56 therein as shown particularly in FIG. 13 which slots
register with each other. The tray is composed of a material such
as preferably a plastic and the slots 56 result in a flexible wall
portion 57. Between the flexible portion 57 and the main body of
the tray there is formed a tapered notch 58 as shown particularly
in FIG. 11 and when the tray is swung into the closed position as
shown in the upper part of FIG. 1 the notch 58 engages over the
post 21 of the handle half 16 as shown particularly in FIG. 13. The
flexible strip portion 57 has an arc-shaped depression 60 in which
the post 21 engages resulting in a releasable detent enabling the
tray to be moved to a released position by pressure on the finger
piece 50 a distance sufficient where the tray can be grasped
directly and moved to a fully open position such as indicated at
25' in FIG. 1.
The tray 25 provides a platform with the stack of blades normally
threaded over a longitudinally extending rib 70 thereon, the rib
extending up through the blade slots 31. Normally in removing a
blade from the stack in the handle the knife is held in the left
hand and positioned horizontally as shown in FIG. 1 with the tray
and blade stack facing upwardly as indicated in FIG. 14 which is
reversed from the position shown in cross-sectional FIG. 3. The rib
70 has a lug 73 projection extending upwardly at each end with an
intervening depression 74 and the right half 15 of the handle has a
fixed cross rib 75 extending into the depression 74 (FIG. 3).
Accordingly the top of the blade stack is maintained below the tops
of the lugs 73 and, bearing in mind that in removing a blade the
tray and related elements will be reversed from that shown in FIG.
3, the arrangement ensures against any interference in opening the
tray.
The tray embodies structural means of advantage in removing
individual blades and particularly the last blade of the stack
which on a flat tray surface would be subject to cohesion thereto.
The top surface of the tray as seen in FIGS. 11 and 14 has a pair
of raised but low rails 76 extending longitudinally of the tray
with a connecting cross rail 77 on which the blade stack normally
rests. To select a new blade the tray is swung to a position such
as that indicated at 25' in FIG. 1 and the operator then applies
finger pressure, usually through the thumb, to the top of the stack
nearest to the pivot point 17 as indicated at F in FIG. 14 which by
cantilever action about the cross rail 77 as a fulcrum elevates the
outer end of the stack to the position indicated at 26' in FIG. 14
where it is freely exposed for easy removal of the top blade. The
arrangement is of particular advantage when the last blade in the
stack is reached. The rails maintain the last or bottom blade
elevated from the tray surface and avoid cohesion to an overall
flat surface and the finger pressure elevates the outer end of the
blade where it is readily peeled off by the fingers of the
operator's other hand. It should be understood that when reference
is made herein including the claims the term "stack" is intended to
apply where there is one or more blades positioned on the tray.
When the knife is not in use the blade holder 27 and its blade may
be rotated into the position shown in FIG. 13 where the normally
working edge of the blade and the protective sleeve 40 are
positioned within the handle between the fingers 50a of the tray
member 25 and the then outer end of the blade is locked within the
halves of the blade retainer as indicated at 27a in FIG. 13. Also
in this position the blade tray is locked against outward movement
since the corner 78 of the blade lies in the path of the inner
surface 79 of the part connecting the spaced fingers 50a at the
outer end of the tray 25. The blade holder and its blade may be
readily clamped into the blade edge protective position by
tightening the screw 18.
The blade 26a may be easily removed from the handle by removing
screw 18 and sliding out the retainer which is easily opened to
release a blade and a new blade inserted. The cutting position of
the knife may be reversed from that shown in FIG. 1 by removing the
blade holder and turning it over and clamping it in the reversed
position.
Various modifications and changes may be made in the handle and the
operating parts comprising different embodiments of the principles
of the invention. Accordingly it is intended that all matter
contained herein shall be interpreted as illustrative and not in a
limiting sense.
* * * * *