Title:
FINGER MOUNTABLE GUITAR STRING CONTACT DEVICE
United States Patent 3854368


Abstract:
A device is provided for snug mounting on the middle segment of the fourth finger of a guitar player for use in altering the normal vibration of a vibrating guitar string. The device can be rotated from a full storage position on the dorsal side of the finger to a full use position on the ventral side of the finger. Intermediate partial use positions between the full storage and full use positions are possible. The device includes a generally cylindrical string contact member having a longitudinally extending axis, the length of which varies according to the specific circumferential location on the surface thereof. The maximum axial length of the string contact member is such that when the device is positioned with the maximum length on the dorsal side of a finger, the finger is useable to perform virtually all of the normal guitar playing fingering movements. In addition, the device is constructed to permit mounting on a finger with a part thereof in a position intermediate the dorsal and ventral sides of a finger of a user for contacting at least one vibrating guitar string while permitting substantially unincumbered movement of the finger on which the device is mounted.



Inventors:
POGAN L
Application Number:
05/453859
Publication Date:
12/17/1974
Filing Date:
03/22/1974
Assignee:
POGAN L,US
Primary Class:
Other Classes:
984/110
International Classes:
G10D3/00; (IPC1-7): G10D3/00
Field of Search:
84/319,322
View Patent Images:
US Patent References:
3638525FINGER GLIDE BAR1972-02-01Sciurba et al.
3457822STEEL GUITAR,STEELS AND METHOD1969-07-29Mull
3442169GUITAR PICK HOLDER1969-05-06Bowers
1748053Apparatus for playing stringed instruments1930-02-25Blair
1741285Pick for musical instruments1929-12-31Carpenter
0413579N/A1889-10-22
0388519N/A1888-08-28



Primary Examiner:
Franklin, Lawrence R.
Claims:
What is claimed is

1. A device to be mounted on a finger for use in altering the vibration of a normally vibrating guitar string, said device comprising: string contact means extending at least partially around the circumference of a finger for contacting a vibrating guitar string; said string contact means having a longitudinal axis, a first end and a second end spaced circumferentially from said first end; said string contact means having a length along said longitudinal axis being a first value at said first end and being a second value, smaller than said first value, at said second end; means for snugly mounting said string contact means on the finger of a user so that said longitudinal axis is aligned with said finger; said mounting means and said string contact means being constructed and arranged to permit said string contact means first end to be selectively mounted in a use position on the ventral side of a user's finger, in a storage position on the dorsal side of a user's finger, and in a position on a user's finger intermediate said dorsal side and said ventral side.

2. The invention according to claim 1 wherein said mounting means is fixed to said string contact means at an included angle of approximately 80° relative to said longitudinal axis thereof.

3. The invention according to claim 1, said length of said string contact means at said first end being a value to permit contact thereby of at least three strings of a guitar with said first end of said device being mounted on the medial segment of a finger of a user on the ventral side thereof.

4. The invention according to claim 1, said length of said string contact means at said second end being of a value to permit contact of at least two strings of a guitar thereby with said device being mounted on the medial segment of a finger of a user with said second end of said string contact means being on the ventral side thereof.

5. The invention according to claim 1, said length of said string contact means at said second end being of a value to permit contact of one string of a guitar thereby with said device being mounted on the medial segment of a finger of a user with said second end of said string contact means being on the ventral side thereof.

6. The invention according to claim 1, said length of said string contact means at said second end being a value to permit contact of two strings of a guitar, said respective lengths of said string contact means first and second ends each being a value to permit flexing of a finger of a user with said device mounted on the medial segment thereof with said string contact means first end located intermediate the dorsal and ventral sides of said finger.

7. The invention according to claim 6, said string contact means first and second ends being circumferentially spaced from one another a given amount such that said second end is located on the ventral side of said finger upon said first end being intermediate said dorsal and ventral sides thereof.

8. The invention according to claim 1, said length of said string contact means at said first end being a value to permit flexing of a finger upon said device being mounted on the medial segment of said finger with said first end intermediate said dorsal and ventral sides of said finger.

9. The invention according to claim 8 wherein said mounting means includes means for accommodating expansion of a medial segment of a finger upon said device being mounted on the medial segment of a finger and said finger being flexed.

10. A device to be mounted on a finger for use in altering the vibration of a normally vibrating guitar string, said device comprising string contact means extending at least partially around the circumference of said finger for contacting a vibrating guitar string, said string contact means having a longitudinal axis, means for mounting said string contact means on a finger with said longitudinal axis thereof being aligned with said finger, said string contact means including a generally rectangular first contact section and a tapering second contact section, said first contact section including a longitudinal axis and a transverse axis, said first contact section being arranged relative to said mounting means with said longitudinal axis thereof being aligned with the longitudinal axis of said string contact means and extending along said longitudinal axis for a length within a range of about three to five centimeters, said second contact section having a base and tapering therefrom in the direction of said transverse axis to an end wall, said base being contiguous to said first contact section and said end wall being spaced from said first contact section, said end wall being generally aligned with the longitudinal axis of said contact means and having a length in said longitudinal direction of about one to one and one-half centimeters.

11. The invention according to claim 10, said string contact means including a third contact section contiguous to said second contact section and extending along the direction of said longitudinal axis of said string contact means a length of approximately one half centimeter.

12. A device for mounting on a finger for use in contacting a vibrating guitar string to alter the normal vibration thereof, said device comprising a guitar string contact member of a generally cylindrical configuration having a longitudinal axis, means for snugly mounting said string contact member on the finger of a user for controlled movement on said finger about said axis, said cylindrical configuration of said contact member varying in longitudinal extent at disparate circumferential locations about said contact section from a first, maximum length to a second, minimum length, said total contact section extending over less than about 180°, said contact section and said mounting means being constructed and arranged to permit mounting of said device with said mounting means on the medial segment of a finger of a user with said first, maximum string contact section adjacent the outside of a user's finger, said first maximum length being of a value to permit the flexing of the finger on which it is mounted.

Description:
The present invention relates generally to a device for modifying the normal vibration of a guitar string, and in particular to a finger mountable device for altering the normal vibration of a guitar string which is rotatable between a full use and full storage position on the finger of a user.

In recent times the guitar has become one of the more popular musical instruments. Both the electric guitar and the non-electric or acoustic guitar have become very popular with great numbers of people. Large numbers of people have been learning to play the guitar either under the tutelage of an instructor or by teaching themselves to play, sometimes with the aid of instruction manuals and/or records.

In the play of a guitar, the instrument is supported either on the knee of a player if the guitar is to be played in a seated position or by a strap or other support attached to the guitar usually worn about the neck and shoulder of a player. For a right-handed player the neck of the guitar is cradled and partially supported by the left hand. The right hand of the player is used to set tautly stretched strings vibrating either by use of a pick which may be made of plastic, bone or some other convenient material and snapping the string or the strings are plucked directly by the fingers.

While the present invention is useable with virtually any type of guitar, its use shall be discussed primarily with regard to the non-electric or acoustic guitar.

Sound produced by a guitar is initiated by plucking or otherwise causing one or more strings on the guitar to vibrate. This vibration is transmitted to the body of an acoustic guitar which enhances the sound produced by the strings. The strings which initiate the sound production are supported at one end on the body or sounding board of the guitar and at the other end on a finger board or neck which extends out from the guitar the strings being normally unsupported between these two points.

The strings are maintained under tension which varies from one string to the next and are either formed of different materials or different thicknesses of the same material. The different tension and differing materials and thicknesses, and a combination thereof, produces different musical notes when the strings are caused to vibrate.

In addition, a single string can be made to produce different notes by effectively shortening its vibrating length by use of the left hand of a right-handed player to force the string to bear against a projection from the neck of the guitar. This pressure against a projection, called a fret, raises the frequency of vibration of a vibrating string higher than the frequency of the string when the entire string vibrates.

A student of the guitar first learns basic chords and notes and how to produce them consistently. Once having mastered the basics, the student progresses toward producing special effects on the guitar by varying the basic vibration of a vibrating string.

Numerous devices exist which are used by the beginner and experienced guitarist to alter the vibration of a vibrating guitar string thereby producing a sound which varies from the sound produced by a normally vibrating string.

Many years ago it was discovered that the generally cylindrical neck of a bottle, when separated from the main part of the bottle, could be applied by a guitarist with his left hand to bear against vibrating strings. The sound which was produced was pleasant and caused a desirable variation in normal guitar sound. The technique of using the neck of a bottle to vary the sound produced by a normally vibrating guitar string became known as "bottlenecking" and commercial versions of "bottlenecks" appeared in the market.

The "bottlenecks" which appeared were approximately three inches long and of a diameter to permit insertion of a finger of a user therein for aid in controlling application of the bottleneck to the vibrating strings on the neck of a guitar.

A great disadvantage of the commercially available bottlenecks, as well as actual bottlenecks, is that when they are in place on the finger of a user the normal use of the finger is impaired to such a degree that the bottleneck must be removed for normal playing of the guitar.

It is an object of the present invention to provide a device for mounting on the finger of a user for altering the normal vibration of a vibrating guitar string which device is to remain on the user's finger in a storage position when not in use for altering the vibration of a guitar string.

It is a more particular object of the present invention to provide a device for mounting on the finger of a user in a use position for contacting vibrating strings of a guitar and which may be rotated on the finger to a storage position to permit virtual unincumbered movement of the finger in the play of a guitar and is also positionable in an intermediate use position on the finger where it may be used to alter the vibration of vibrating guitar strings while permitting somewhat restricted movement of the finger on which it is mounted.

Broadly, the apparatus of the present invention includes a device to be mounted on a finger for use in altering the vibration of a normally vibrating guitar string. The device includes string contact means extending at least partially around the circumference of a finger for contacting a vibrating guitar string. The string contact means has a longitudinal axis, also has a first end and has a second end spaced circumferentially from the first end. The string contact means has a length along said longitudinal axis, which is a first value at the first end. The length along the longitudinal axis is a second value, smaller than said first value, at the second end of the string contact means. The device includes means for snugly mounting the string contact means on the finger of a user so that the longitudinal axis is aligned with the finger. The mounting means and the string contact means are constructed and arranged to permit the string contact means first end to be selectively mounted in a use position on the ventral side of a user's finger, in a storage position on the dorsal side of a user's finger, and in a position on a user's finger intermediate the dorsal side and the ventral side.

The above brief description as well as further objects, features and advantages of the present invention will be more fully understood by reference to the detailed description of the presently preferred but nonetheless illustrative embodiment in accordance with the present invention when taken in conjunction with the accompanying drawing, wherein:

FIG. 1 is a perspective view of an illustrative form of the present invention shown from the underside of the string contact means;

FIG. 2 is a plan view of the device of the present invention showing the underside of the string contact means;

FIG. 3 is an elevation view of the device of the present invention showing FIG. 2 viewed from the right;

FIG. 4 is a sectional elevation view taken substantially along the line 4--4 of FIG. 2 and looking in the direction of the arrows;

FIG. 5 is a sectional elevational view taken substantially along the line 5--5 of FIG. 2 and looking in the direction of the arrows;

FIG. 6 is a perspective view of a prior art device;

FIG. 7 is an end view of the device of the subject invention looking from the left of FIG. 1;

FIG. 8 is a perspective view showing the device of the subject invention in place on a finger of a user;

FIG. 9 is a side view of the device of the present invention showing the device in place on a finger of a user showing said device in a suggested use;

FIG. 10 is a view of FIG. 9 taken from the left thereof;

FIG. 11 is a plan view of the neck of a guitar showing the size of part of the string contact means of the device of the present invention in phantom as it would appear in relation to a guitar neck and guitar strings;

FIG. 12 is a view of the device of the present invention in place on the finger of a user in a storage position with the finger shown pushing on a guitar string;

FIG. 13 is a view of the device of the present invention in a storage position on the finger of a user with the finger being used to pull a guitar string;

FIG. 14 is a view of the device of the present invention shown in a use position on the finger of a user with the device being applied to four strings of a guitar; and,

FIG. 15 is a view of the device of the present invention showing the inside of the string contact means with a finger of a user shown in phantom with the device shown in a use position relative to said finger and said device being applied to four strings of a guitar.

Referring now specifically to the drawing and first to FIG. 1, in accordance with an illustrative embodiment demonstrating objects and features of the present invention, there is provided a finger mountable guitar string contact device, generally designated by the reference numeral 20, which may be fashioned of metal, glass or ceramic and which includes a string contact means 22. A mounting means 24 is fixed to the string contact means.

Both the string contact means 22 and the mounting means 24 are made of a substantially rigid material and may be separately formed of metal and fixed to one another by welding or the like or may be integrally formed of plastic by injection molding or the like. Both the string contact means 22 and the mounting means 24 should be constructed to be relatively non-yielding for a purpose to be described more fully hereinafter.

As may be most clearly seen by reference to FIG. 2, the string contact means 22 is generally oblong and includes a longitudinally extending length axis which generally extends along the line 4--4 of FIG. 2. The string contact means 22 is formed to curve one half way or approximately 180° around the finger of a user as may be seen by reference to FIG. 8, and the axis thereof generally extends longitudinally in the same direction as the finger of a user when the device 20 is mounted thereon.

The string contact means 22, as may be best seen in FIGS. 1, 2 and 8, has first and second ends generally designated by reference letters A and C with end A being circumferentially spaced from end C.

As may be seen by reference to FIG. 2, the length of the string contact means 22 at one end A is a given value and the width at the other or second end C is a second given value, less than said first given value.

The string contact means 22 is shown in the preferred embodiment as being generally curved to generally follow the outer contour of a finger of a user (see FIGS. 8 and 10). Naturally, other configurations for the string contact means 22 are possible including plane or other than generally cylindrical curves or combinations thereof.

The mounting means 24 is a generally cylindrical ring shaped member and is fixed to the string contact means 22 forming an included angle, designated by the reference letter D in FIG. 4, of approximately 80° with the axis of the string contact means 22.

The mounting means 24 is not centered with respect to the longitudinal dimension of the string contact means 22 but is closer to the end 26 of the string contact means 22 than it is to the end 28 thereof.

As may be best seen by reference to FIG. 2, the string contact means 22 includes what may be described as a generally rectangular section of substantially the same length for a part of its circumferential extent or width to a point designated B on the end 26 thereof and which extends to a point designated by the letter E on the end 28 thereof. As may be noted by reference to FIG. 2, the point B on the side 26 of the string contact means 22 is displaced about the circumference or width of the string contact means from the point E for a purpose to be described hereinafter.

Circumferentially past the points B and E on the ends 26, 28 of the string contact means 22, the length along the axis thereof of the string contact member tapers and decreases until it reaches its smallest length at a point indicated by C (see FIG. 2).

The different length of the longitudinal dimension of the string contact means of the present invention at disparate circumferential locations permits it to remain on the finger of a user and permits flexing of the finger whether the device is in a use or storage position as described hereinafter.

In addition, the angular relationship between the mounting means 24 and the string contact means 22 aids in the present invention being useable when it is necessary or desirable to bend the finger on which it is mounted as described hereinafter.

FIG. 7 most clearly shows that the mounting means 24, which is generally cylindrical on its interior surface 30, includes a relief 32 therein. The relief 32, if the mounting means 24 is fashioned of metal, may be formed by a broach or some other machining process. If the device 20 is to be formed by injection molding the mold can contain provision for formation of the relief 32.

The relief 32 aids in positioning the device 20 on the finger of a user by indicating, without visually checking, its location by touch. In addition the relief 32 accommodates for expansion of the medial segment of a finger when it is flexed with the device 20 mounted thereon.

In use, the device 20 is placed on the finger P of a user, normally the fourth finger or pinkie, on a middle segment MS by placing the pinkie P through the mounting member 24 with the end 26 of the string contact means 22 toward the distal segment DS of the pinkie P.

As may be seen by comparing FIGS. 8, 9 and 10, the device 20 is rotatable about the finger P once located on the middle segment MS thereof. Rotation of the device 20 places the string contact means 22 in various locations relative to the finger.

Some of the possible locations on the finger P of the string contact means 22, axis A, are the top or dorsal side of the middle segment MS shown in FIGS. 12 and 13, the ventral or bottom side shown in FIGS. 14 and 15 or in an intermediate position as shown in FIG. 9.

It should be noted that the mounting means 24 is of a fixed interior diameter and is selected to fit on the medial segment MS of the pinkie finger P of a user snugly to prevent unwanted rotation of the string contact member 22 with respect to the finger P once the device is in place thereon.

As may be seen by reference to FIGS. 8 and 12 through 15, the device 20 is placed on the finger of a user with the mounting means 24 turned so as to place the end 26 of the string contact means 22 toward the forward or distal segment DS of the finger P. The placement of the end 26 toward the distal segment DS of the finger P, by virtue of the location of the mounting means 24 toward the end 26 of the string contact means 22, mounts the device 20 on the medial segment MS of the finger with a greater proportion of the string contact means 22 extending basally of the end of the finger P than distally thereof.

This arrangement of the device 20, in conjunction with the approximate 10° off-set from the vertical of the included angle D (see FIG. 4) permits virtual complete freedom of movement of the finger P when the device 20 is rotated on the finger P to the storage position with the end A on the dorsal or top side of the finger as shown in FIG. 8. The flexed position of the finger P shown in phantom in FIG. 8 illustrates this freedom of movement.

As will be explained more fully hereinafter, flexing of the finger P is required to perform many of the "action touches" used by the advanced guitar player which require great dexterity and strength. In addition, the fact that the mounting means 24 is sized to snugly mount the device 20 on the finger P of a user permits secure positioning of the device in either the full storage position shown in FIGS. 8, 12 and 13 or in the full use position shown in FIG. 14 or in a position intermediate the full storage and full use position as shown in FIG. 9.

FIGS. 9, 10, and 11 show a fragment of the finger board or neck N or an acoustic guitar to demonstrate one of the manners of use of the device 20 of the present invention. Typically, an acoustic guitar has six strings S which are generally spaced apart from one another approximately 7/16 inch or approximately 1.1 centimeters. The strings S' of an electric guitar are typically spaced somewhat closer together being generally on the order of 3/8 inch or approximately 0.95 centimeters. The strings S' of an electric guitar are represented in FIGS. 14 and 15.

The primary use of the device 20 of the present invention occurs when it is desired to alter the vibration of a normally vibrating guitar string by applying part of the string contact means 22 to at least one of a plurality of vibrating guitar strings S (see for example, FIGS. 9 and 10).

Contacting the vibrating strings S with part of the string contact means 22, without causing the strings to contact a fret R, alters the sound which emanates from the string by adding or subtracting various overtones but without changing the basic note emanating therefrom.

Typically, the method of changing the note emanating from the vibrating string in this manner is followed by sliding the device 20 up and down the neck N of the guitar while maintaining the string contact means 22 in contact with the string as indicated in FIG. 14. The technique of thus varying the sound produced by a vibrating string of a guitar is termed "bottlenecking."

The bottlenecking technique is extensively used by the amateur and the professional guitar player when playing what is generally termed "blues" or "rock" music and is becoming an increasingly popular technique with many guitarists.

Due to the popularity of the technique of "bottlenecking" commercially available slides for use in "bottlenecking" exist in the market place. An example of a typically available bottleneck slide L is shown in FIG. 6. The slide L is generally cylindrical and approximately 2 to 21/2 inches long and may be made of glass, ceramic or metal. Typically, the slide L is designed to be placed on the third finger of the left hand of a right-handed guitar player and generally covers all of the medial segment and a substantial portion of the distal segment of the third finger of the user on which it is mounted.

The slide L is designed to be used in the manner described above when "bottlenecking" is desired and must be removed from the finger of a user when it is desired to otherwise use the finger on which it is mounted. The third finger must be bent when varying the tone produced by a vibrating string in a normal manner by forcing the string to bear against a fret R.

In addition the finger must be bent if it is desired to use the finger on which the slide L is mounted for one of the action touches described hereinafter. As may be seen by reference to FIG. 6, bending of the finger is impossible with the slide L in place thereon.

In view of the necessity for removal of the slide L whenever it is desired to play the guitar to produce sound other than those produced by "bottlenecking" the prior art slide L is most inconvenient to use. In addition, the lack of ready availability of the slide L for use greatly hinders artistic variations of sound which would be possible if the slide L did not prohibit normal use of the finger on which it is mounted.

As may be seen by reference to FIG. 11, the length of the device 20 of the present invention in the axial direction which would align with the finger of a user is sufficient to contact three strings S of an acoustic guitar and would, of necessity, be on the order of between 31/2 and 4 centimeters at its maximum dimension along the side designated A of FIGS. 2 and 7.

FIG. 7 shows, in end view, the circumferential extent of the string contact means 22 (which as noted above is approximately 180°) and the circumferential extent of what may be generally termed a rectangular section or segment of the device 20.

It has been found by experimentation that a range for the maximum axial length for the string contact member of approximately 3 to 5 centimeters permits bottlenecking of a sufficient number of strings to permit use of the device on three strings S of an acoustic guitar (FIG. 11) when the device is mounted on a finger in the use position with the maximum dimension on the ventral side of the middle segment MS of the finger P of a user.

As may be seen by reference to FIGS. 14 and 15 the same three to five centimeter length range permits bottlenecking of four strings S' on an electric guitar due to the closer spacing of the strings thereon (see FIGS. 14 and 15).

In addition, a maximum length of approximately five centimeters along the longitudinal axis of the string contact member permits rotation of the device 20 to a full storage position with the maximum dimension on the dorsal side of the middle segment MS of a finger P as shown in FIGS. 8, 12 and 13 without interfering with normal use of the finger P in applying pressure on the strings against a fret or in executing some of the action touches to be described.

As may be noted by reference to FIGS. 1 through 4, 8, 9, and 15, the length along the longitudinal axis of the string contact means 22 varies from the edge A to the edge C tapering to a dimension which is approximately one centimeter long at edge C and which includes a central segment which is approximately 2.5 centimeters long. Naturally, the device may be formed with the string contact means terminating at a smallest length of 2.5 centimeters and having a circumferential extent of only approximately 90°.

As may be best seen by reference to FIG. 9, the part of the string contact means 22 which is approximately 2.5 centimeters wide, is useable to contact two strings S for bottlenecking thereof when the device 20 is mounted on the finger P of a user on the median segment MS thereof in a position intermediate the full storage and full use positions. This position, which may be termed a compromise or partial use position, is illustrated in FIG. 8 as well and, as may be seen by reference to FIG. 8 and the phantom view of the finger P shown therein, only slightly restricts the movement of the finger P when mounted in the intermediate position due to the reduction in length of the contact means 22 while still permitting use of the device 20 for bottlenecking as shown in FIG. 9.

One of the "action touches" referred to above is the technique of "bending" which is an often-used technique for altering the sound produced by a vibrating guitar string which changes the pitch thereof.

Bending is accomplished by pushing or pulling a string with a force which is applied perpendicularly to the length of a string S and FIG. 13 illustrates the use of a finger P in pulling a string S. As may be seen by reference to FIG. 13, pulling a string S requires bending or flexing of the finger P between the medial and distal segments thereof.

In addition to pushing and pulling on the string, bending requires that pressure be simultaneously applied to the string and that the pressure be directed toward the neck N of the guitar for the note to sound. Bending results in a temporary tightening of the string S being played thereby raising the pitch from the original pitch produced by plucking or striking the string and permitting a variation in the sound produced thereby.

A slow rate of bending (push, pull, push, pull, etc.) will slowly raise the frequency of the sound produced, and, conversely, rapid bending will rapidly raise the pitch of the sound being produced.

If bending is repeated rhythmically, a sound variation termed vibrato results and, as is well-known, vibrato is often used by guitarists not only in popular music but in classical music as well.

As may be seen by reference to FIG. 6, if the slide L of the priot art were mounted on the finger of a user and it was desired or necessary to use that finger to produce vibrato, the required bending of the finger would be impossible. To produce vibrato, the slide L would have to be demounted from the finger and remounted thereon when it was again desired to produce the slurring sound greatly facilitated by the slide L.

The device 20 of the present invention permits mounting of the device 20 on the finger of a user in the full use position shown in FIGS. 10, 14 and 15 for bottlenecking. If it is then desired to perform bending or some of the other action touches, the device 20 may be rotated to the full storage position shown in FIGS. 12 and 13. With the device in the full storage position unhampered bending of the finger P is possible with the length along the longitudinal axis being sufficient to permit bending without the device 20 contacting the neck of the guitar.

Further, as may be seen by reference to FIGS. 8 and 9, the device is mountable on the finger of a user in a partial position intermediate the use and storage positions whereby contact of two strings for bottlenecking is possible with only limited restriction of finger movement and is even mountable with the smallest length of the string contact means 22 in position on the distal part of the medial segment of the finger of a user while permitting almost complete freedom of movement of the finger P.

As noted above, the circumferential size of the mounting means 24 should be selected to snugly mount the device 20 on the medial segment MS of the finger P of the user. The snug mounting of the device permits retention of the device 20 in the use, storage or intermediate positions without unwanted rotation thereof to a position which is not desired by the user.

As will be readily apparent to those skilled in the art, the invention may be used in other specific forms or for other purposes without departing from its spirit or essential characteristics. The present embodiment is, therefore, to be considered as illustrative and not restrictive, the scope of the invention being indicated by the claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalents of the claims are therefore intended to be embraced therein.