U.S. patent number 3,787,899 [Application Number 05/270,605] was granted by the patent office on 1974-01-29 for ear muff assembly.
This patent grant is currently assigned to Imperial Optical Company Ltd., trading as Safety Supply Co.. Invention is credited to Alois Albin Krawagna.
United States Patent |
3,787,899 |
Krawagna |
January 29, 1974 |
EAR MUFF ASSEMBLY
Abstract
An ear muff assembly for use with a headband including an ear
cup, a circerentially extending first bearing, the ear cup being
mounted in the first bearing for rotation about a first axis, a
yoke, the circumferentially extending bearing being mounted in the
yoke for rotation about a second axis which extends laterally of
the first axis, the yoke being mountable on the headband.
Inventors: |
Krawagna; Alois Albin (Toronto,
Ontario, CA) |
Assignee: |
Imperial Optical Company Ltd.,
trading as Safety Supply Co. (Toronto, Ontario,
CA)
|
Family
ID: |
23032012 |
Appl.
No.: |
05/270,605 |
Filed: |
July 11, 1972 |
Current U.S.
Class: |
2/209; 381/371;
381/378 |
Current CPC
Class: |
H04R
1/1066 (20130101); H04R 1/1008 (20130101); H04R
5/0335 (20130101) |
Current International
Class: |
H04R
1/10 (20060101); A41d 021/00 () |
Field of
Search: |
;2/209,6
;179/156R,182R,156,182 ;181/33R,20 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Franklin; Jordan
Assistant Examiner: Nerbun; Peter
Attorney, Agent or Firm: Gordon W. Hodson et al.
Claims
What I claim as my invention is:
1. An ear muff assembly comprising
a. a U-shaped head band having a pair of oppositely disposed ends,
a transverse ridge projecting inwardly of said U-shaped
configuration at each end of said head band, a longitudinal ridge
projecting outwardly of said U-shaped configuration at each end of
said head band and extending longitudinally thereof,
b. a pair of Y-shaped yoke members each having a leg portion
releasably connected at one end to an end of said head band and a
pair of arm portions projecting outwardly from the other end of
said leg portion, said one end of each leg portion being formed
with a U-shaped channel adapted to receive an end of said head band
in a close fitting sliding relationship, a pair of flanges
projecting inwardly of the U-shaped section of said leg portion and
extending longitudinally of said leg portion from said one end of
said leg portion, said flanges being spaced from the base of the
U-shaped channel a distance which is less than the combined
thickness of the head band and the transverse ridge at the end of
the band whereby the ends of said head band are releasably locked
in said U-shaped channels, said arm portions having transversely
extending axially aligned passages formed adjacent the outer ends
thereof, said arms being formed to locate said axially aligned
passages inwardly of the arc of curvature of said head band,
c. a pair of ear cup members, each having a central axis, an outer
surface and an inner surface, said cup members opening inwardly
from said head band and being disposed inwardly of said yoke
members to be located directly between said yoke members and the
head of the wearer in use, a circumferentially extending recessed
bearing channel formed in a unitary portion of the outer surface of
each of said cup members concentric with respect to said central
axis,
d. a bearing collar having a circumferentially extending body
portion adapted to fit within said recessed bearing channel of each
ear cup in a close fitting sliding relationship whereby said ear
cup may be rotated with respect to said bearing collar about said
central axis, each of said bearing collars having a pair of
diametrically opposed bearing shafts projecting radially from
diametrically opposite sides of said body portion, said shafts
being mounted for rotation within said transversely extending
axially aligned passages of said arms of said yoke member to permit
rotation of said ear cups about the axis of said transversely
extending passages,
e. said bearing collar being radially split in a plane which
extends through said body portion and at least one of said bearing
shafts whereby said body portion may be opened to permit location
of said collar in said recessed grooves, at least one of said
transversely extending passages of said yoke retaining the two
portions of a split shaft therein to lock said body portion of said
bearing collar within said bearing channel of said ear cup, and
f. said head band and yoke members being rotatable about said
central axis of said cup members by rotation of said bearing collar
members with respect to said cup members through an angle of at
least 120.degree. whereby the head band may be moved from a
position overlying the head of the wearer to a position underlying
the head of the wearer as required in use.
2. An ear muff assembly comprising
a. a generally U-shaped head band,
b. a pair of Y-shaped yoke members, each having a leg portion
connected at one end of said head band and a pair of arms
projecting outwardly from the other end of said leg portion, said
arms having transversely extending aligned passages formed therein
adjacent the outer ends thereof,
c. a pair of ear cup members opening inwardly of said head band and
mounted inwardly of said yoke members to be disposed directly
between said yoke members and said head band whereby the clamping
force of said head band is transmitted directly to said ear cups,
said ear cups having a circumferentially extending recessed bearing
channel formed in a unitary portion of the outer surface
thereof,
d. a bearing collar having a circumferentially extending body
portion adapted to fit within said recessed bearing channel of each
ear cup in a close fitting sliding relationship whereby said ear
cup may be rotated with respect so said bearing collar about said
central axis, each of said bearing collars having a pair of
diametrically opposed bearing shafts projecting radially from
diametrically opposite sides of said body portion, said shafts
being mounted for rotation within said transversely extending
axially aligned passages of said arms of said yoke member to permit
rotation of said ear cups about the axis of said transversely
extending passages,
e. said bearing collar being radially split in a plane which
extends through said body portion and at least one of said bearing
shafts whereby said body portion may be opened to permit location
of said collar in said recessed grooves, at least one of said
transversely extending passages of said yoke retaining the two
portions of a split shaft therein to lock said body portion of said
bearing collar within said bearing channel of said ear cup.
3. An ear muff assembly as claimed in claim 2 wherein said arms of
said yoke member extend inwardly of the arc of curvature of said
head band to dispose said collar member radially inwardly of said
arc of curvature of said head band, whereby said head band may be
spaced outwardly.
Description
FIELD OF INVENTION
This invention relates to ear muff assemblies. In particular, this
invention relates to an ear muff assembly for use with a headband
wherein the ear muffs are pivotally mounted about two axes without
forming passages in the cup to provide the pivotal mounting.
PRIOR ART
Ear muff assemblies such as sound absorbing muffs and head phones
are mounted on headbands so as to be positional over the ears of
the wearer. Generally, the headband is intended to extend upwardly
over the head of the wearer. However, in many applications the
wearers prefer to locate the headband in an area remote from the
hair, either in front of or behind the head. Where the ear muffs
are circular, this presents no problem in that the ear muffs may be
positioned at any position relative to the ear. It is, however,
frequently desirable to contour the ear muffs so as to fit
comfortably over the ears of the wearer and to provide for a
mounting of the ear muffs to permit the headband to be moved
relative to the ear muffs when being worn. The pivotal mountings
which have been provided prior to the present invention employ a
mounting screw or pivot pin which extends through the cup and
pivotally connected to a support carried by the headband. It has
been found that a pivot pin mounted directly in a passage formed in
the ear cup decreases the effectiveness of the sound attenuation of
the ear muffs by reason of the fact that vibrations established in
the headband are transmitted directly to the walls of the ear cup.
Furthermore, the assembly of the component parts of the ear muff to
include a pivot pin mounted within the ear cup is time
consuming.
SUMMARY OF INVENTION
The present invention overcomes the difficulties of the prior art
described above by providing an ear muff assembly which is simple
in construction and inexpensive to assemble and which provides a
pivotal mounting of the ear muff about two axes without requiring a
pivot pin extending through the walls of the cup.
According to the embodiment of the present invention, an ear muff
assembly for use with the headband includes the improvement of an
ear cup, a collar, the ear cup being mounted in the collar for
rotation about the first axis extending normal to the ear cup, a
yoke for the collar, the collar being mounted in the yoke for
rotation about a second axis which extends laterally of the first
axis and means for mounting the yoke on a headband.
PREFERRED EMBODIMENT
The invention will be clearly understood after reference to the
following detailed specification read in conjunction with the
drawings wherein,
FIG. 1 is a pictorial view of an ear muff assembly according to an
embodiment of the present invention;
FIG. 2 is a sectional view in the direction of the line 2--2 of
FIG. 1;
FIG. 3 is a pictorial view of a collar according to an embodiment
of the present invention; and
FIG. 4 is a sectional view taken along the line 4--4 of FIG. 2.
With reference to the drawings, the reference numeral 10 refers
generally to a head set according to the present invention which
includes a pair of ear muff assemblies 12 connected to one another
by means of a headband 14. Each of the ear muff assemblies 12
consists of a yoke 16, a cup 18 and a collar 20.
The yoke 16 has a generally U-shaped lower end having a pair of
arms 22 formed with axially aligned passages 24. The upper end of
the yoke is formed with a resilient body portion 26 and side walls
28, each of which have inwardly directed flanges 30 cooperating
with the body portion 26 to form a channel for receiving the
headband 14. The headband 14 has a ridge at each outer end thereof
which engages the inner edge of the flanges 30 when the yokes are
mounted on the headband (FIG. 2).
Each of the cups 18 has an outer surface 32, an inner surface 34
and an end face 36. The outer surface 32 is formed with an annular
U-shaped bearing recess 38. In the embodiment illustrated, the
inner surface 34 is formed with a radially projecting face 40
disposed inwardly from the edge 36. A shallow annular groove 42
extends around the inner face of the cup adjacent the face 36. An
end plate 44 is formed with a shoulder 46 adapted to fit in a close
fitting relationship within the groove 42 so as to mount the ring
44 in a position extending over the edge 36 of the cup. A resilient
pad 48 is adapted to extend over the face of the plate 44 and has a
lip 50 which extends over the adjacent side wall of the plate 44
and the cup 18 so as to be mounted thereon. The collar 20 (FIG. 3)
provides a circumferentially extending first bearing and has an
inner surface 52 and a pair of side surfaces 54 adapted to fit in a
close fitting sliding relationship within the U-shaped channel 38.
A pair of circular lugs 56 project radially from the outer surface
57 of the collar 20. One of the lugs 56 is radially split so as to
provide a pair of oppositely disposed faces 58. Each of the lugs 56
is formed with an annular recess 60 disposed inwardly of the end
thereof. The lugs 56 are adapted to fit in a close fitting
relationship within the passages 24 of the yoke 16. The annular
recess 60 is adapted to receive a small flange formed adjacent the
inner end of the passages 24 of the yoke so that the lugs may be
retained therein.
The ear muffs are assembled as shown in FIG. 1 of the drawings so
that the cup is rotatable about a first axis 62 (FIG. 2) which
extends substantially normal to the head engaging surfaces by
rotating the cup relative to the collar 20. The cup is also
rotatable about an axis 64 which extends transversely of the arms
of the yoke 16 by rotating the collar relative to the yoke about
the lugs 56. The muff may be rotated about the axis 64 from the
normal position shown in FIG. 2, the two alternative broken line
positions also shown in FIG. 2 of the drawings.
In use, the ear muffs may be placed over the ears of the wearer
with the headband in any position relative to the ear muffs by
reason of the rotation provided by the mounting of the collar on
the cup and the ear muffs may be aligned with the head of the
wearer by rotation of the muffs about the axis 64.
An important feature of the present invention is the fact that the
pivotal mounting of the cup relative to the headband is provided
without mounting any pivot pins in passages extending through the
body of the cup. It will be noted that any vibrations picked up by
the headband will not be transmitted directly to the cup in view of
the fact that there is no rigid connection between the headband and
the wall of the cup. Furthermore, the fact that there are no
passages opening through the wall of the cup prevents extraneous
vibrations being transmitted to the interior of the cup.
The muffs may be used to either dampen sound or as receiver ear
phones. When the muffs are used as ear phones, a speaker 66 is
mounted on a face plate 68 which is in turn mounted on the radially
extending ledge 40 of the cup. The speaker 66 is disposed within
the cup and a through passage 70 (broken lines, FIG. 2) is formed
in the walls of the cup to permit a conductor to communicate with
the speaker. In use, the conductor will be sealed within the
passage 70 by means of a suitable sealing compound. It will be
noted that forming a passage in the wall of the cup to receive a
conductor does not have the same deleterious effect on the sound
attenuation characteristics as the mounting of a pivot on the cup
or in a passage formed through the wall of the cup.
To assemble the ear muff of the present invention, the collar 20 is
located in the position extending around the U-shaped channel 38.
The mounting of the collar in the channel 38 is facilitated by
splitting at least one of the lugs 56 as shown in FIG. 3 of the
drawings. When the collar is in position, the yoke is located over
the lugs 56. The yoke serves to clamp the split sections of the
split lug 56 together so as to maintain the collar in a close
fitting sliding relationship within the channel 38. It will be
noted that the ear muff assembly may be completed without requiring
any hand tools.
From the foregoing, it will be apparent that the present invention
provides a simple and inexpensive ear muff assembly for use with
teh headband which has the advantage of being pivotable about a
pair of axes without the direct mounting of a pivot pin through the
wall of the ear cup.
The ear cup collar and yoke may be formed from any of the well
known materials used for the manufacture of ear muffs. The
construction of the ear muff for the present invention is
particularly suitable for moulding in plastic material and may be
formed from a plastic material such as LEXAN (trade mark),
available from Canadian General Electric Company Limited.
Various modifications of the present invention will be apparent to
those skilled in the art without departing from the scope of the
invention. For example, the collar 20 may be split along both lugs
56 so this is formed in two parts. It is, however, advantageous to
form the collar in one part as it facilitates the assembly of the
device.
It will also be understood that the circumferentially extending
bearing formed by the collar 20 may also be provided by a pair of
arcuately shaped segments, each of which may have a pivot pin
formed thereon for engagement with the yoke.
It will be apparent to those skilled in the art that it is not
essential to form the circumferentially extending first bearing
means to extend around the entire length of the bearing surface of
the cup. However, as previously indicated, the split collar has the
advantage of being easy to mount and remove as required in use.
* * * * *