Tubular cutting instrument

Claim 2

In a cutting instrument having an elongated tubular housing formed with a cutting orifice, a resilient, inner tubular member slidably mounted coaxially within said tubular housing, and driving means for reciprocating said inner tubular member, the improvement comprising: means defining a bend in said tubular housing between said driving means and said cutting orifice displacing said cutting orifice in a direction toward said resilient, inner tubular member, such that as the end of said resilient, inner tubular member passes across said cutting orifice, said end is resiliently urged into shearing contact with said cutting orifice.

Claim 3

The apparatus of claim 1 in which said cutting orifice is displaced by said bend a distance toward said resilient, inner tubular member which exceeds the clearance between said housing and said inner tubular member.

Claim 4

The apparatus of claim 1 in which said cutting orifice is displaced by said bend a distance toward said resilient, inner tubular member which exceeds the clearance between said housing and said inner tubular member by a factor of between two and six.

Claim 5

The apparatus of claim 1 in which said housing comprises first and second cylindrical sections joined by an intermediate section, said first section having a smaller inner diameter than said second section, said orifice being located in said first section, and said bend displacing said first section angularly with respect to said second section.

Claim 6

The apparatus of claim 1 in which said inner tubular member is made of full-hard stainless steel and said tubular housing is made of fully annealed stainless steel.

Claim 7

In an ophthalmic instrument for removing vitreous and the like from the eye having an elongated, tubular housing with an outer diameter less than 0.100 inch formed with a cutting orifice, an inner, resilient tubular member slidably mounted coaxially within said tubular housing with a clearance of less than 0.0015 inch, and driving means for reciprocating said inner tubular member, the improvement comprising: means defining a bend in said tubular housing between said driving means and said cutting orifice displacing said cutting orifice in a direction toward said inner, resilient tubular member a distance which exceeds said clearance, so that as the end of said inner, resilient tubular member passes across said cutting orifice, said end is resiliently urged into shearing contact with said cutting orifice.

Claim 8

In an ophthalmic instrument for removing vitreous and the like from the eye having an elongated, tubular housing with an outer diameter less than 0.100 inch formed with a cutting orifice, an inner, resilient tubular member slidably mounted coaxially within said tubular housing with a clearance of less than 0.0015 inch, and driving means for reciprocating said inner tubular member, the improvement comprising: means defining a bend in said tubular housing between said driving means and said cutting orifice displacing said cutting orifice in a direction toward said inner, resilient tubular member a distance which exceeds said clearance, so that as the end of said inner, resilient tubular member passes across said cutting orifice, said end is resiliently urged into shearing contact with said cutting orifice.

Claim 9

In an ophthalmic instrument for removing vitreous, lens and the like, from the eye, having an elongated tubular housing with an open end and a closed end, an orifice formed in said tubular housing, an inner tubular member slidably mounted coaxially within said tubular housing, said inner tubular member providing a passage for the vitreous material, and the like, drive means for producing relative axial movement between said tubular housing and said inner tubular member, means coupling said inner tubular member to a vacuum source to draw vitreous, and the like, up through said inner tubular member; and means for introducing replacement fluid into the eye to maintain constant pressure within the eye; the improvement comprising: a bend in said tubular housing between said driving means and said cutting orifice displacing said orifice toward said inner tubular member, such that as the end of said inner tubular member passes across said orifice, said end is resiliently urged into shearing contact with said orifice.

Claim 10

In an ophthalmic instrument for removing vitreous, lens and the like, from the eye, having an elongated tubular housing with an open end and a closed end, an orifice formed in said tubular housing, an inner tubular member slidably mounted coaxially within said tubular housing, said inner tubular member providing a passage for the vitreous material, and the like, drive means for producing relative axial movement between said tubular housing and said inner tubular member, means coupling said inner tubular member to a vacuum source to draw vitreous, and the like, up through said inner tubular member; and means for introducing replacement fluid into the eye to maintain constant pressure within the eye; the improvement comprising: a bend in said tubular housing between said driving means and said cutting orifice displacing said orifice toward said inner tubular member, such that as the end of said inner tubular member passes across said orifice, said end is resiliently urged into shearing contact with said orifice.