Improvements in Clamps Used in Dentistry.
Year: 1894

page_text: Date of Application, 19th May, 1894
Complete Specification Left, 19th Nov., 1894-Accepted, 22nd Dec., 1894
Improvements in Clamps Used in Dentistry.
A communication from abroad by HENRY F. LIBBY, of 307, Boylston Street,
Boston, in the State of Massachusetts, one of the United States of America,
Dentist.
I ALFRED GEORGE BROOKES of 55 & 56 Chancery Lane, London, Chartered
Patent Agent, do hereby declare the nature of this invention to be as follows:-
This invention relates to rubber-dam clamps used extensively in dentistry.
Clamps of this class, as usually constructed, are provided with two or more arms
adapted to be clasped upon a tooth and hold down, out of the way, a piece of
rubber placed about the adjoining teeth and covering a portion of the gum, to
prevent dampness reaching the cavity being operated upon.
The arms of the clamp, as usually constructed, are turned inwardly and preferably
shaped and sharpened to grasp at opposite sides, the neck of a tooth, the neck
being that portion of the tooth at or immediately below the termination of the
enamel.
A clamp constructed to engage a tooth in this manner, must, of necessity, have
its two arms or members of substantially the same length, for if one arm is longer
than the other the two arms will not act opposite each other upon the tooth, and
the clamp will not therefore be firmly held upon the tooth.
The inner arm of the clamp, ie., the arm which acts upon the inside of the tooth,
cannot engage the tooth below the neck without being buried in the gum, while it
is frequently necessary, in operating upon what are commonly known as labial
cavities, that the outer arm engage the outer face of the tooth at a considerable
distance below the neck of the tooth, or at or near the point at which the outer
face of the tooth enters the gum, which is usually at a much lower level than the
point at which the inner face enters the gum.
The object of this invention. is to provide a rubber-dam clamp which can be
applied to a tooth with its outer arm engaging the tooth at a point considerably
below the neck, i.e., below any labial cavity, and which may be firmly retained
in position clasping the tooth without necessitating the burying of the inner
arm in the gum.
To accomplish this object I provide the inner arm of the clamp with a clasping
shoe jointed to the end of said arm, and hollowed at its upper end to clasp the neck
of the tooth, said shoe bearing upon the gum below the neck of the tooth, thereby
enabling the end of the inner arm attached to the said shoe, to be carried dowD
upon but without entering the gum, to such a level that it will act against the
tooth substantially opposite the clasping end of the outer arm, said shoe, by clasping
the neck of the tooth, retaining the clamp firmly in position.
My improved clamp comprises say two arms or members preferably united by a
resilient or spring crown portion say a single piece or strip of resilient metal though
said arms may be otherwise formed or connected, if desired.
The lower or clasping end of the outer arm may be turned inwardly, and is made
concave and sharpened to embrace the outer face of a tooth.
The lower or clasping end of the inner arm, is connected, by a hinge joint or
pivot, to a clasping shoe which may be a substantially flat piece of metal concaved

page_text: and preferably sharpened at its inner end, to engage or clasp the inner face of a
tooth at its neck, and at its opposite end made rounding to better fit the contour of
the gum.
Preferably-say
if a labial cavity, be located below the neck of a tooth, and in
operating upon this cavity, it is desirable that the rubber-dam and clasping end of
the outer arm of the clamp be considerably below the cavity to permit free
manipulation of the instruments.
c
To apply my improved clamp to a tooth having such a labial cavity, the ends of
a pair of spring pliers such as are commonly employed for this purpose, are inserted
in the hole in the end and in the eye formed at the end of the arm and the two arms
spread to enable the clamp to be placed upon the tooth, the inturned clasping end
of the outer arm' being placed against the face of the tooth below the cavity, and
the shoe placed with its clasping end under the neck of the tooth at the inner face
thereof, and permitted to press upon the gum below the neck.
While if the concave knife edge of the shoe engages the neck of the tooth above
the gum; the point of attachment of the arm is carried below the said neck and
upon the gum so as to carry the said end down to a position substantially opposite
the clasping end of the arm at the outer side face of the tooth, the ends of the
two arms being pressed towards and substantially opposite each other by the spring
crown thereby retaining the clamp firmly in position upon the tooth.
The shoe may be made louger or shorter as desired, to carry the end of the inner
arm to a greater or less. distance below the neck of the tooth to bring it at such a
level or
or position as shall cause it to act substantially opposite the end of the outer
arm, yet the said shoe is never objectionable when resting upon the gum as shown,
and by clasping the neck of the tooth at its upper end, holds the clamp firmly in
position.
The neck of the tooth at the inner side is always higher or nearer the top of the
tooth than the neck at the outer side of the tooth, and it is evident that a clamp, in
which the two arms are of equal or of substantially equal length, even when applied
with its clasping ends at the neck of the tooth at each side, must stand in an
inclined position, and the inclination would be much more were it attempted to
carry the clasping end of the outer arm down below the neck for a labial cavity
without carrying the clasping end of the inner arm also below the neck.
When this is attempted the inclination is found to be so great as to cause the
end of the outer arm to slip upwardly upon the tooth towards the neck thereof,
making it impossible to hold the dam down below the cavity.
With my improved device, however, the shoe upon the end of the inner arm,
while clasping the neck of a tooth, enables the end of said arm to be carried to a
considerable distance below the said neck to thereby bring it in proper operative
position with relation to the clasping end of the outer arm, when the latter engages
the tooth low down upon the outer fave thereof.
Preferably the inturned clasping end of the outer arm is offset from the arm in
such a manner as to carry the arm to one side of the tooth to clear the instruments
when in use.
I prefer to apply the shoe to the inner member or arm of the clamp alone,..but
the said shoe may be applied to any other member or members of the clamp if
found desirable.
The shoe may be of metal with no soft or padded face, for such a face would not
be suitable for dental work, the sole object of the shoe being to distribute the
pressure upon the gum to prevent pain, and at the same time embrace or clasp, the
neck of the tooth to hold the clamp in position, for the said clamp would not be
held in position if the shoe did not engage the tooth.
Dated the 18th dor of M 1904
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicant..

page_text: A communication from abroad by HENRY F. LIBBY, of 307, Boylston Street,
Boston, in the State of Massachusetts, one of the United States of America,
Dentist..
I ALFRED GEORGE BROOKES of 55 & 56 Chancery Lane in the County of
London, Chartered Patent Agent, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement':―
This invention relates to rubber-dam clamps.used extensively in dentistry.,
Clamps of this class, as usually constructed, are provided with two or more
arms adapted to be clasped upon a tooth and hold down, out of the way, a piece
of rubber placed about the adjoining teeth and covering a portion of the gum, to
prevent dampness reaching the cavity being operated upon..
The arms of the clamp, as usually constructed, are turned inwardly and
preferably shaped and sharpened to grasp at opposite sides the neck of a tooth...
the neck being that portion of the tooth at or immediately below the termination
of the enamel.
A clamp constructed to engage a tooth. in this. manner, must,, of necessity have
its two arms or members of substantially the same length, for if one arm is longer
than the other the two arms will not act opposite. each other upon the tooth, and
the clamp will not therefore be firmly held upon the tooth.
The inner arm of the clamp, i.e., the arm which acts upon the inside of the
tooth, cannot engage the tooth below the neck without being buried in the gum,
while it is frequently necessary, in operating what are commonly known as, labial
cavities, that the outer arm engage the outer face of the tooth at a considerable
distance below the neck of the tooth, or at or near the point at which the outer
face of the tooth enters the gum, which is usually at.a. much lower level than the
point at which the inner face enters the gum.
The object of this invention is to provide a rubber-dam clamp which can be
applied to a tooth with its outer arm engaging the tooth at a point considerably
below the neck, i.e., below any labial cavity, and which may be firmly retained in
position clasping the tooth without necessitating the burying of the inner arm in
the gum
To accomplish this object I provide the inner arm of the clamp with a clasping
shoe jointed to the end of said arm, and hollowed at its upper end to clasp the
neck of the tooth, said shoe bearing upon the gum below the neck of the tooth,
thereby enabling the end of the inner arm attached to the said shoe, to be
carried down upon but without entering the gum, to such a level that. it will
act against the tooth substantially opposite the clasping end of the outer
arm, said shoe, by clasping, the neck of the tooth, retaining the clamp firmly in
position.
:
In the drawing,
Fig. 1 represents in perspective, one form of clamp embodying my invention,
as it will appear when applied to a tooth with the clasping end of its outer arm
low down to clear a labial cavity, the rubber-dam being omitted for the sake of
clearness..
Fig. 2, a view looking at the face of the tooth upon which the clamp.
clasped; and
Fig. 3 a perspective view of the clamp by itself.
is
Referring to the drawing, my improved clamp comprises the two arms.or

page_text: members a, a, preferably united by a resilient or spring crown portion a², and
shewn as formed from a single piece or strip of resilient metal, though said arms,
so far as concerns my present invention may be otherwise formed or connected if
desired.
The lower or clasping end as of the outer arm a is turned inwardly, as shewn,
and is made concave and sharpened to embrace the outer face of a tooth.
The lower or clasping end of the inner arm a¹ is connected by a hinge joint or
plvot á², to a clasping shoe b, shewn as a substantially flat piece of metal concaved
and preferably sharpened at its inner end 2, to engage or clasp the inner face of a
tooth at its neck, and at its opposite end 3 made rounding to better fit the contour
of the gum.
:
Referring now particularly to Figs. 1 and 2, 4 represents a labial cavity located.
below the neck: 5 of a tooth, and in operating upon this cavity, it is desirable
that the rubber dam and clasping end of the outer arm of the clamp be
considerably below the cavity to permit free manipulation of the instruments.
To apply my improved clamp to a tooth having such a labial cavity, the ends of
a pair of spring pliers such as are commonly employed for this purpose, are
inserted in the hole 6 in the end a and in the eye 7 formed at the end of the
arma, and the two arms spread to enable the clamp to be placed upon the tooth,
the inturned clasping end as of the outer arm a being placed against the face of
the tooth below the cavity, and the shoe 6 placed with its clasping end under the
neck of the tooth at the inner face thereof, and permitted to press upon the gum
below the neck, as shewn,
By reference to Fig. 1 it will be seen that while the concave knife edge 2 of the
shoe b engages the neck of the tooth above the gum, yet the point of attachment/a
of the arm a' is carried below the said neck and upon the gum so as to carry the
said end down to a position substantially opposite the clasping end 1 of the arm a
at the outer side face of the tooth, that the ends of the two arms being pressed
towards and substantially opposite each other by the spring crown a³, thereby
retain the clamp firmly in position upon the tooth:
: :
The shoe b may be made longer or shorter as 'desired to carry the end of the
inner arm a¹ to a greater or less distance below the neck of the tooth to bring it
at such a level or position as shall cause it to act substantially opposite the end of
the outer arm, yet the said shoe is never objectionable when resting upon the gum
as shewn, and by clasping the neck of the tooth at its upper end, holds the clamp
firmly in position.
The neck of the tooth at the inner side is always higher or nearer the top of the
tooth than the neck at the outer side of the tooth, and it is evident that a clamp, i
in which the two arms are of equal or of substantially equal length, even when
applied with its clasping ends at the neck of the tooth at each side, must stand in
an inclined position, and the inclination would be much more were it attempted to
carry the clasping end of the Outer arm down below the neck for a labial cavity
without carrying the clasping end of the inner arm also below the neck:
When this is attempted the inclination is found to be so great as to cause the
end of the outer arm to slip upwardly upon the tooth towards the neck thereof,
making it impossible to hold the dam down below the cavity.
'With my improved device, however, the shoe upon the end of the inner
arm, while clasping the neck of a tooth, enables the end of said arm to
be carried to a considerable distance below the said neck to thereby bring it
in proper operative position with relation to the clasping end of the outer arm,
when the latter engages the tooth low down upon the outer face thereof.
"It will be noticed that the inturned clasping end of the outer arma is offset
from the arm in such a manner as to carry the arm, see Fig. 2, to one side of the
tooth to clear the instruments when in use.
!.:
I have herein shewn and prefer to apply the shoe to the inner member or arm
of the clamp alone, but the said shoe may be applied to any other member or
members of the clamp if found desirable."
9...
1

page_text: The shoe herein shewn is of metal and has no soft or padded face, for such a
face would not be suitable for dental work, the sole object of the shoe being to
distribute the pressure upon the gum to prevent pain and at the same time embrace
or clasp the neck of the tooth to hold the clamp in position for the said clamp
would not be held in position if the shoe did not engage the tooth.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. A rubber dam clamp, consisting of an-shaped spring having one of its arms
bent inwardly and concaved at its end to fit the neck of a tooth, and a metallic
shoe pivoted to the other arm of said spring and adapted to press upon the gum,
said shoe being also hollowed at one end to fit the neck of a tooth at the inner
side of the latter, substantially as described.
2. A rubber dam-clamp, consisting of a shaped spring having one of its arms
bent inwardly and adapted at its end to clasp the neck of a tooth at the outer
side thereof, and a metallic clasping shoe pivoted to the end of the other arm of
said spring and adapted at its upper end to clasp said tooth also at the neck and
at the inner side thereof and to carry the end of the said other arm below the said
neck, substantially as described.
3. The construction or arrangement and use of a dental clamp having its parts
adapted to co-operate substantially as and for the purpose hereinbefore described
and shewn by the drawings.
Beted the 10th dow of November 1894.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicant.