U.S. patent number 3,810,305 [Application Number 05/248,304] was granted by the patent office on 1974-05-14 for blade unit.
This patent grant is currently assigned to The Gillette Company. Invention is credited to Roger L. Perry.
United States Patent |
3,810,305 |
Perry |
May 14, 1974 |
BLADE UNIT
Abstract
A safety razor blade unit is constructed for use with a safety
razor handle having a head portion which is of fixed size and shape
and which includes movable latch means. The blade unit comprises a
frame and blade means secured in the frame. The frame defines a
recess of the above-mentioned fixed size and shape for receiving
the handle's head portion therein. The blade unit also comprises
latch structure disposed to be engagable with the handle latch
means when the handle head portion is so received in the blade unit
recess.
Inventors: |
Perry; Roger L. (Lynnfield
Center, MA) |
Assignee: |
The Gillette Company (Boston,
MA)
|
Family
ID: |
22938530 |
Appl.
No.: |
05/248,304 |
Filed: |
April 27, 1972 |
Current U.S.
Class: |
30/47; 30/50;
30/346.58 |
Current CPC
Class: |
B26B
21/24 (20130101) |
Current International
Class: |
B26B
21/24 (20060101); B26B 21/08 (20060101); B26b
021/54 (); B26b 021/06 () |
Field of
Search: |
;30/32,50,51,62-65,68,346.58,346.59 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Smith; Al Lawrence
Assistant Examiner: Smith; Gary L.
Attorney, Agent or Firm: Ertman; Willis M.
Claims
What is claimed is:
1. A safety razor blade unit adapted to be releasably mounted upon
a safety razor handle head portion which is of fixed size and shape
and includes movable latch means,
said blade unit comprising a frame and blade means secured in said
frame,
said frame defining an elongated recess that includes a bottom
surface and opposed side surfaces that extend parallel to the
cutting edge of said blade means, said opposed side surfaces
adapted to engage cooperating surfaces of said handle head portion
for providing positive positioning of said blade unit relative to
said handle head portion, and
said blade unit further comprising latch structure disposed to be
engageable with said handle latch means when said handle head
portion is received in said recess, said latch structure comprising
a pair of projections extending outwardly from the bottom surface
of said recess, each said projection comprising a stem portion and
a wider foot portion defining an inclined planar latch surface that
faces the bottom surface of said recess and an inclined camming
surface facing away from said frame, each camming surface merging
in a smoothly rounded surface with a latch surface.
2. A blade unit as claimed in claim 1 wherein said recess is of
generally rectangular configuration and said foot portions extend
parallel to the long dimension of said recess.
3. A blade unit as claimed in claim 1 wherein said recess is of
generally rectangular configuration and said foot portions extend
transversely to the long dimension of said recess.
4. A safety razor blade unit adapted to be releasably mounted upon
a safety razor handle head portion which is of fixed size and shape
and includes movable latch means, said blade unit comprising a
frame comprising cap and base members and blade means clamped
therebetween said frame defining a recess of said fixed size and
shape for receiving said handle head portion therein, said blade
unit further comprising latch structure integral with said frame
disposed to be engageable with said handle latch means when said
handle head portion is received in said recess, said latch
structure comprising a projection from the under side of said base
member, said projection comprising a stem portion and a wider foot
portion defining a planar latch surface for engagement with said
handle latch means, said latch surface facing said under side of
said base member and further including a camming surface facing
away from said under side of said base member, said camming surface
merging in a smoothly rounded surface with said latch surface.
5. A blade unit as claimed in claim 4 wherein said recess defining
structure includes two spaced, opposed surfaces that extend
parallel to the cutting edge of said blade means for engaging
cooperating surfaces of said handle head portion.
6. A blade unit as claimed in claim 4 wherein said recess is of
generally rectangular configuration and said foot portion extends
parallel to the long dimension of said recess.
7. A blade unit as claimed in claim 4 wherein said recess is of
generallly rectangular configuration and said foot portion extends
transversely to the long dimension of said recess.
8. A safety razor blade unit adapted to be releasably mounted upon
a safety razor handle head portion which is of fixed size and shape
and includes movable latch means, said blade unit comprising a
frame and blade means secured in said frame, said frame defining a
recess of said fixed size and shape for receiving said handle head
portion therein, said recess including spaced, opposed surfaces for
engaging cooperating surfaces of said handle head portion, said
blade unit further comprising latch structure disposed to be
engageable with said handle latch means when said handle head
portion is received in said recess, said latch structure comprising
a pair of spaced, planar projections that extend outwardly from
said recess, each said projection comprising a stem portion and a
wider foot portion that defines a pair of planar latch surfaces
that face outwardly in opposite directions from said stem portion
for engagement with said handle latch means.
Description
This invention relates to safety razors and, more particularly, to
blade units suitable for releasable mounting on a safety razor
blade.
It is a principal object of the present invention to provide a
blade unit which is simple and inexpensive to manufacture while
providing for easy attachment to and removal from a safety razor
handle.
It is an additional object to provide a blade unit which can be
firmly retained on a safety razor handle while engaging the handle
only on the under side of the blade unit, thereby allowing the
provision of blade unit cutting edges on opposite sides of the
handle.
A safety razor blade unit constructed according to the invention is
designed for use with a safety razor handle having a head portion
which is of fixed size and shape and which includes movable latch
means. The blade unit comprises a frame and blade means secured in
the frame. The frame defines a recess of the above-mentioned fixed
size and shape for receiving the handle's head portion therein. The
blade unit also comprises latch structure disposed to be engagable
with the handle latch means when the handle head portion is so
received in the blade unit recess. In preferred embodiments the
frame comprises plastic cap and base members and the latch
structure comprises a projection having a stem portion integral
with the base member and a wider foot portion which defines a pair
of latch surfaces. It is also preferred that the recess be
rectangular in shape, and that there be provided a pair of planar
parallel projections which project from the recess.
Other objects, features, and advantages of the invention will
appear from the following description of particular preferred
embodiments taken together with the accompanying drawings. In the
drawings:
FIG. 1 is a perspective view of a razor handle and a blade unit
constructed according to the invention suitable for use with that
handle;
FIG. 2 is a partially broken-away, exploded view of the handle of
FIG. 1;
FIG. 3 is a partially broken-away top plan view of the handle of
FIG. 1;
FIG. 4 is a partially broken-away front elevation of the upper
portion of the handle of FIG. 1;
FIG. 5 is a sectional side view of the upper portion of the handle
of FIG. 1 and the blade unit of FIG. 1, the blade unit being
retained on the handle in position for a shaving operation;
FIG. 6 is a view similar to FIG. 5 with the blade unit being
removed from the handle;
FIG. 7 is a bottom plan view of the blade unit of FIG. 1;
FIG. 8 is a view taken at 8--8 of FIG. 7;
FIG. 9 is a perspective view of an alternative embodiment of a
razor handle and a blade unit constructed according to the
invention suitable for use therewith;
FIG. 10 is a side elevation of the handle and blade unit of FIG.
9;
FIG. 11 is a view taken at 11--11 of FIG. 10;
FIG. 12 is a view similar to FIG. 11 with the blade unit being
removed from the handle;
FIG. 13 is an exploded perspective view of the upper portion of the
handle of FIG. 9 and of the blade unit of FIG. 9;
FIG. 14 is a bottom plan view of the blade unit of FIG. 9;
FIG. 15 is a view taken at 15--15 of FIG. 14; and
FIG. 16 is a view taken at 16--16 of FIG. 14.
One preferred embodiment may be described with reference to FIGS.
1-8. Referring in particular to FIG. 1, there is shown a safety
razor comprising a handle 10 and a blade unit 12 releasably
mountable upon the handle. The handle includes integral elongated
grip portion 14 and head portion 15, the latter suitable for
receiving the blade unit 12. The handle is 4.295 inches high and
the head portion 15 defines an upper rectangular surface which is
1.560 inch long and 0.420 inch wide, having a central rectangular
opening 108 for receiving latch members 26 of the blade unit 12.
Spring 84 is disposed in the head portion 15 to engage the blade
unit latch members 26 when the blade unit is mounted on the
handle.
The blade unit 12, which has an overall length of 1.560 inch and an
overall width of 0.800 inch, comprises a pair of plastic cap and
base members 20, 22 which are permanently secured to each other and
which have blade means 166 clamped between them. The member 22
includes a downward-facing recess 24, of generally rectangular
cross section, which is suitable for receiving the upper portion of
handle 10 (as described in detail below). Recess 24 is 0.440 inch
wide, suitable for receiving the head portion of handle 10. The
latch members 26 project downwardly from the bottom of base member
22.
The details of construction of the handle 10 will be described with
reference to FIGS. 1-6.
The handle consists of a plastic body 16, a pair of identical
metallic side plates 60, latch spring 84, and a pair of identical
release members in the form of plastic levers 92 suitable for
applying pressure against portions of the latch spring 84 as
described in detail below.
The plastic body 16 includes a central web 28 which is integral
with symmetrically disposed end panels 30. Panel 30 have a
multiplicity of ridges 18 on their outer surfaces in the grip
portion 14. The longitudinal axis of the handle 10, and in
particular of the grip portion 14, is coincident with the center of
web 28. Reinforcing ribs 32 are provided on opposite sides of web
28 and are integral with web 28 and panels 30. A pair of downwardly
opening notches 31 are provided in the thickened lower end 33 of
web 28.
Panels 30 merge in a smooth curve with flanges 34 of head portion
15. The flanges 34 are generally planar and the plane in which they
lie is generally perpendicular to the axis of the grip portion 14
of the handle. Each flange 34 is integral with a raised platform
36. The upper surface of platform 36 includes a raised portion 38
and a depression 40. The platform 36 is also integral with
downwardly extending reinforcing leg 42, itself integral with the
upper most reinforcing rib 32a and an end panel 30. Rod 44 extends
between legs 42 intermediate platforms 36 and rib 32a. The legs 42
present surfaces 46 which face each other and have a separation of
0.100 inch. Offset parallel end surfaces 48 of platform 36 have a
separation of 0.220 inch. Lips 50 at the outer ends of flanges 34
extend upwardly providing upper surfaces 52 and side surfaces 54.
The metal side plates 60 each include an elongated planar panel 62
having a pair of inwardly directed flanges 64 which extend the
length of panel 62, the width of flanges 64 increasing uniformly
from bottom to top. Foot 66 and upward projection 68 are integral
with panel 62.
Flanges 64 merge at their upper, wider ends with flanges 70 which
protrude from the lower edges of widened head portion 72 of side
plate 60. The head portion 72 includes an integral upper plate 74
projecting from right angle bend 73. The plane of plate 74 is thus
perpendicular to that of vertical surface 71 adjacent bend 73. The
plate 74 includes a central notch 76, 0.210 inch wide and 0.155
inch deep. Tabs 78 are bent downwardly from the inner edge 80 of
plate 74. Each tab 78 is 0.200 inch wide and extends downwardly
from the upper surface of plate 74 for a distance of 0.090
inch.
Opening 82 is provided in each panel 62 which is 0.100 inch wide
and 0.351 inch high with its lower edge being 0.693 inch below the
upper surface of plate 74.
The panel 62 is 0.357 inch wide at its lower end where it is
integral with foot 66 and each lateral edge of the panel 62 tapers
inwardly at 0.degree.43'. Each flange 64 is approximately 0.105
inch wide at its upper portion where it is integral with flange 70
and tapers at 1.degree.04' to a zero width adjacent foot 66.
Spring 84 is formed in a generally "dumbell" shape from 0.025 inch
diameter stainless steel, spring tempered wire. The central,
narrower formed portion includes parallel lengths 86 of wire which
are separated by 0.155 inch. The total width at each of the wider
formed ends 88 is 0.350 inch and the total length of the spring is
1.440 inch. At one of the ends 88 the two ends 90 of the wire from
which the spring 84 is formed are bent back toward the center of
the spring.
Levers 92 are molded from a resilient plastic and are mounted for
rotational movement about rod 44. Each lever includes a surface 94
for engagement of a length 86 of spring 84 and has an arcuate
recess 96, having a radius of curvature of 0.050 inch, which
engages the rod 44. Surface 98 above recess 96 and surface 100
below recess 96 (seen best in FIGS. 5 and 6) are inclined to each
other at an angle of 15.degree.. Surface 102, on the opposite side
of the main body 104 of the lever 92 is parallel to surface 100.
Cantilevered finger 106 projects at an angle of 30.degree. from the
lower portion of surface 94 for a distance of approximately 0.200
inch. The finger 106 is approximately 0.015 inch thick and 0.050
inch wide. As best seen in FIGS. 1, 5 and 6, in the assembled
handle 10 the body 104 of lever 92 partially projects through
opening 82 in side plate 60 with exposed surface 102 making an
angle of approximately 30.degree. with the axis of the handle
10.
In the assembled handle 10, spring 84 lies on platforms 36 with
raised platform portions 38 disposed between parallel lengths 86 of
the spring 84. Levers 92 have surfaces 94 in contact with lengths
86 of spring 84, recesses 96 engaged with rod 44, and surfaces 102
protruding through openings 82 in side plates 60. Each side plate
60 has its projection 68 inserted into a notch 31 and flanges 64
disposed between panels 30 to abut reinforcing ribs 32. In the head
portion flanges 70 of the side plates overlie flanges 34 of the
plastic body, while plate 74 overlies platforms 36. Tabs 78 are
disposed within recesses 40 of platforms 36. Recesses 76 on the
upper plates 74 of side plates 60 cooperate to provide a
rectangular opening 108 in the upper surface of handle head portion
15, which surface is defined by plates 72 and edges 52 of lips 50
of a plastic body 16. Central, latching portions 110 of parallel
lengths 86 of spring 84 are exposed in opening 108 as are the upper
portions of levers 92.
The blade unit 12 may be described with reference to FIGS. 1 and
5-8. A frame comprises plastic cap and base members 20, 22 which
are secured together, with blade means 116 disposed therebetween,
by means of pins 124 of member 20 which pass through cooperating
openings 126 in member 22. Pins 124 have deformed heads 128 which
bear upon bosses 130 of member 22 to secure the components of blade
unit 12 together as a single unit. The member 22 includes a
platform comprising integral planar portions 132, 134 the upper,
blade-supporting surfaces of which intersect in an angle of
140.degree.. (The axis of handle 10 bisects this angle so that each
blade lies in a plane inclined at 70.degree. to the handle's axis).
Outer blade supports 136 are connected to the platform by webs 138
defining debris removal apertures 139. Guard structures 140 are
spaced apart from supports 136 and are connected thereto by webs
142. Apertures 144 are thus provided between the guard structures
140 and the supports 136.
The base member 22 has a set of five ribs 146 extending
transversely across the lower surfaces of portions 132, 134 and
integral therewith. Ribs 146 provide downwardly facing, horizontal
surfaces 148 and, where the ribs 146 are integral with webs 138,
vertical surfaces 150. Surfaces 148 and 150 cooperate to define the
recess 24 mentioned above. As best seen in FIG. 7 a symmetrically
located pair of ribs 146a includes tiny crushbump locators 151
protruding from its vertical surfaces 150a. Latch members 26,
integral with portions 132, 134, include an upper stem 154 and a
wider foot portion 156 which serves as a latching structure and has
shoulders 158 adjacent the stem 154. Camming surfaces 160 are
provided on portions 156 below shoulders 158. (Rectangular openings
162, 164 in portions 132 and 134 simplify molding of plastic member
22.)
Cap member 20 includes an opening 161 in each end wall 163 (best
seen in FIG. 1). A pair of projections 165 protruding from the
central undersurface of member 20 are seated in appropriately
positioned recesses 167 (best seen in the embodiment of FIG. 15) on
member 22.
The blade means, indicated generally at 166, comprises two sets,
each set including a pair of blades 168, 170 having cutting edges
172, 174 respectively, and a spacer 176 between the blades. Edges
172 overlie slots 144 and edges 174 are spaced further inwardly of
the blade unit 12 from edges 172. Blades 168, 170 and spacers 176
include appropriate openings for receiving projections 124.
Additionally, lower blades 168 include openings aligned with
apertures 139 of member 22 (see FIG. 7), thereby permitting shaving
debris which is deposited between blades 168 and 170 to flow
through apertures 139 and away from cutting edges 172, 174.
In the embodiment described above, the blade unit 12 is releasably
mountable on the handle 10 as follows. The blade unit 12 is moved
toward the handle 10 oriented such that the planes of the stems 154
of latch members 26 are parallel to the axis of the handle 10 with
the latch members 26 directly above opening 108 in the upper
surface of the handle head portion 15. As the blade unit and handle
are brought together, the camming surfaces 160 on latch members 26
force the center, latch sections 110 of spring lengths 86 away from
each other to permit the passage of wider, lower portions 156 of
latch structures 26 past the spring. As this is accomplished, the
respective spring latch portions 110 snap back to their original
configuration and latch the shaving head 12 to the handle by
bearing upon shoulders 158, as best seen in FIG. 5.
In addition to the latching action between the handle and blade
unit, the recess 24 in the underside of blade unit 12 serves as a
socket to receive the appropriately shaped and sized head portion
15 of handle 10. Specifically, the horizontal surfaces 148 of ribs
146 engage the upwardly facing flat portions 74 of side plates 60
and edges 52 of lips 50. The flat vertical side surfaces 71 of side
plates 60 adjacent the right angle bend 73 engage the vertical
surfaces 150 at the sides of recess 24. The crush-bump locators 151
deform to accommodate the exact size of the particular handle head
portion and thereby assure a snug fit.
The snug fit of the head portion of the handle into the recess
formed in the lower portion of the blade unit is effective to
prevent slight relative movement of the blade unit with respect to
the handle during a shaving operation, while the latching
engagement of the latch members (i.e., spring portions 110) of the
handle with the latch structures 26 of the blade unit serves to
retain the blade unit upon the handle.
With the blade unit 12 thus mounted on the handle 10 the razor is
ready for use in a shaving operation. Removal of the blade unit 12,
for replacement or other reasons, is accomplished by exerting
compressive force against the oppositely disposed surfaces 102 of
the movable levers 92 thus causing rotation, in opposite senses, of
the levers 92 about the rod 44. Surfaces 94 bear upon latch
sections 110 of the spring 84 and force those sections outwardly
against the force of the spring as a whole, the levers 92 thus
serving as release members. This motion of the spring latch
sections 110 removes them from engagement with shoulders 154 on
blade unit latch members 26 and thus unlatches the blade unit 12
thereby permitting its removal (see FIG. 6).
As best seen in a comparison of FIGS. 5 and 6, this rotation of
levers 92 also causes a deformation of the levers 92 in that the
projection 106 is bent toward the main body of the respective lever
92. Since the lever 92 is formed from a resilient plastic material,
this deformation produces a biasing force, in addition to the force
exerted by spring 84, tending to return the levers 92 to the
orientation shown in FIG. 5 once the external force exerted by the
razor's user is withdrawn.
(Openings 161 in end walls 163 of member 20 provide for a thin
central portion of end walls 163 which serve to permit flexure of
member 20, as may occur, for example, during assembly of the blade
unit.)
Another embodiment of the invention is illustrated by FIGS. 9-16.
The blade unit 12a is identical to the blade unit 12 of FIGS. 1 and
5-8 but for the 90.degree. rotation of latch members 26a and
openings 162a, 164a (best seen in FIG. 14).
The handle 200 includes an elongated grip portion 202 of generally
circular cross section and tapering diameter and a head portion
203. The handle 200 is substantially the same height as the handle
described above and the upward facing surfaces (discussed further
below) of the head portion 203 again define a rectangle 1.560 inch
long and 0.420 inch wide.
The handle grip portion 202 comprises a metallic body 204 and a
pair of plastic inserts 206, each having a multiplicity of ridges
208. The head portion 203 is mounted upon a reduced diameter
portion 210 of metallic body 204 and comprises a base 212, a pair
of springs 214, and a cap 215. Base 212 includes a pair of side
edges each having a depressed central portion 218 which support
springs 214. End walls 220 of base 212 provide side edges 222 and
upper edges 224. The cap 216 includes horizontal plate 226 and
vertically disposed side flanges 228 integral therewith. Plate 226
has a central opening 230 and depressed tongues 232 on either side
of opening 230 spaced apart therefrom. Downward projecting tabs 234
are integral with plate 226 adjacent the side edges of opening 230.
Raised end portions 236 of the side edges of base 212 join the
depressed central portions 218 to provide stop surfaces 238. The
upper surface of plate 226 and edges 224 of end walls 220 define
the rectangular structure, mentioned above, which can be received
in the recess 24 (see FIG. 15) on the associated blade unit.
Springs 24 are accordian-like, formed wire compression springs
having five parallel formed legs each, with neighboring legs
connected by rounded 180.degree. bends. The innermost legs 214a
serve, in a manner to be described, as latch members for engagement
with latch structures 26a on blade unit 12a.
In the assembled handle, base 212 is mounted upon portion 210 of
body 202 and springs 214 are supported on edge portions 218 with
their outermost legs abutting stop surfaces 238. The innermost legs
214a of springs 214 underlie opening 230 of cap 216 and abut the
side edges of tabs 234. The cap 216 is placed over the base 212
with flanges 228 lying outside of side edges 236, 218. Ends 220 of
base 212 are crimped inwardly to retain cap 216 in place. Tongues
232 cooperate with stop surfaces 238 to provide a firm structure
against which the outermost lengths of springs 214 bear.
Movable release member 240 is disposed within body 204 and includes
a head 242 having inclined surfaces 244 which engage the innermost
lengths 214a of springs 214. The opposite end 246 of member 240 is
provided with teeth 248 which engage mating structure 249 on the
internal surface of actuator 250. Actuator 250 includes a portion
252 which extends beyond the outer end of body 204 and flange 254
immediately thereabove. Coil spring 256 is disposed around actuator
250 between flange 254 and stationary ring 258.
In the assembled handle, spring 256 biases actuator 250, and thus
movable member 240, downwardly for a maximum exposure of portion
252 and maximum withdrawal of head portion 242 of member 240 below
springs 214. The user may apply pressure to portion 252 to overcome
the biasing force of spring 256 and move plunger 240 in the
direction of cap 216 of the handle 200. As this is done the tapered
surfaces 244 cam outwardly (i.e., toward the respective ends 220 of
base 212) the innermost lengths 214a of springs 214 (compare FIGS.
11 and 12).
The attachment and release of a blade unit 12a to the handle 200 is
as follows. The blade unit 12a is brought together with the cap 216
with latch members 26a aligned with opening 230. The head portion
242 of plunger 240 is located centrally within the opening 230 and
is sized to fit between the two members 26a as they are inserted
through the opening 230. As the blade unit 12a and handle are
brought together, surfaces 160a of members 26a cam lengths 214a of
springs 214 outwardly. After the surfaces 160a have passed below
the level of lengths 214a, the latter spring back into their
original positions and latch the members 26a by bearing upon
shoulders 158 adjacent stem portions 154, as best seen in FIG. 11.
Concurrently, edges 224 and 222 of end portions 220 of base 212
engage surfaces 148a and 150 of outermost ribs 146 and plate 226
engages surfaces 148 and 150 of interior ribs 146 (see FIG.
11).
Release of the blade unit 12 is accomplished by the user by
applying pressure to portion 252 of actuator 250, as described
above. This pressure forces plunger 240 upward thereby causing
surfaces 244 to cam length 214a of springs 214 outwardly, thus
releasing the latching action upon shoulders 158 and permitting
removal of the blade unit 12a, as shown in FIG. 12.
While particular presently preferred embodiments of the invention
have been described in detail, it will be apparent that other
embodiments are within the scope of the invention and the appended
claims.
* * * * *