US3822461A - Disposable lancet - Google Patents

Abstract

A disposable lancet used for piercing the tissue of a finger to obtain blood specimens. The lancet is designed to contain minimum material to achieve low material costs which still have the strength and rigidity to be completely functional. The lancet design permits multiple lancets to be punched from a strip of sheet steel to obtain economy in the manufacturing operation.

Description

I ited States Patent [191 aimstrom DISPOSABLE LANCET Inventor: Sven-Erik Malmstrom, Reftele,

Sweden Assignee: Swedish Hospital Supply SHSAB,

Malondal, Sweden Filed: June 22, 1973 Appl. N0.: 372,487

Related U.S. Application Data Division of Ser. No. 182,862, Sept. 22, 1971.

US. Cl. 29/415 1m. e1B2ld 28/06 Field at Search 113/116 BB; 29/412, 415,

References Cited UNITED STATESPATENTS 11/1875 Lyon 29/415 [451 July 9, 1974 3,037,271 6/1962 Schilberg 29/415 3,143,793. 8/1964 Griffitts etal. 29/417 FOREIGN PATENTS OR APPLICATIONS 1,013,193 4/1952 France 29/412 Primary Examiner-Richard J. Herbst Attorney, Agent, or Firm-Albert L. Jeffers; Roger M. Rickert ABSTRACT A disposable lancet used for piercing the tissue of a finger 'toobtain blood specimens. The lancet is designed to contain minimum material to achieve low material costs which still have the strength and rigidity to be completely functional. The lancet design permits multiple lancets to be punched from a strip of sheet steel to obtain economy in the manufacturing operation. 1

4 Claims, 2 Drawing Figures 1 DISPOSABLE LANCET RELATED APPLICATION This is a Divisional Application of my co-pending application, Ser. No. 182,862, filed Sept. 22, 1971.

BACKGROUND OF THE INVENTION The invention described herein relates to surgical instruments and more particularly to a lancet used for collecting small amounts of blood for test purposes.

A lancet is a'surgical instrument having a sharp pointed end used for piercing the tissue of a patients finger to obtain blood specimens. It is manufactured from stainless steel and comprises a piercing portion having a sharp point which merges into 'a shoulder of substantially greater width which restricts the penetration depth of the lancet. The shoulder is integrally formed with a relatively long handle or grip portion having an outer end (pressure surface) against which a persons thumb is placed for pushing the pointed end of the lancet into the tissue of a finger.

Conventional lancets of this-kind have a handle or grip portion of' uniform width, and the handle width is determined more with regard to the required size of the pressure surface and the'shoulderthan with regard to the required stiffness of the lancet.

As a result, the handle includes substantially more material than is necessary for the lancet to perform its intended function. It has been estimated that the cost for materials in a lancet constitutes more than 40 percent Of the lancet sales price and it therefore is obvious that reduction in the amount of material used will be reflected in reduced costs to the purchaser. Also,'for

only once and then discarded and this fact accordingly dictates that the lancet must be designed to achieve ac-- ceptable performance at the lowest manufacturing and material costs.

The present invention reduces the material and manufacturing costs for a lancet by about 50 percent. This reduction is obtained by the fact that the shoulder is connected with the handle by means of a neck portion having'reduced width in'relation to the shoulder and that the width of the handle-increases from the width of the neck portion at the connection thereto in the direction of the free end of the handle. Another feature is that the handle is-provided with recesses which are of the same size and shape as the shoulder portion or sections thereof. For example, the shoulder portion comprises two sections symmetrically positioned or only one section positioned at one side of the lancet. v

To obtain economy in the manufacturing process, lancets preferably are stamped from strips having substantially the same width as the entire length of each lancet, one lancet being positioned in one direction and the adjacent lancets being positioned in the opposite direction, the sections of the shoulder of one lancet being formed by corresponding recesses in the adjacent lancets.

SUMMARY OF THE- INVENTION Briefly stated, the above disadvantages of the prior art are eliminated by providing a disposable lancet which contains the minimum amount of material necessary to impart strength and rigidity to the lancet structure while still permitting the lancet to perform its intended function at an optimum performance level. To

BRIEF DESCRIPTION OF THE DRAWING While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter of the invention, it is believed the invention will be better understood from the following description taken in conjunction'with the accompanying drawing, wherein:

FIG. 1 is a plan view of a steel strip illustrating multiple lancetspunched therefrom during a manufacturing operation; and Y FIG. 2 shows a plan view of a modification of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT I I Referring now to the drawing wherein like reference characters designate like or corresponding parts, there is shown in FIG. 1astrip 10 of stainless steel or other material preferably having a thickness of 0.15 to-O.2O

' mm and of a length sufiicient to stamp out multiple lancets during the manufacturing operation. The plan view of FIG. [shows the configuration of eachlancet 11 as the manufacturing proceeds; To acquire perspective on the size, the lancets of FIG. 1 are shown magnified about five times the actual'size of a lancet used for blood specimen purposes.

Eachlancet 11 is provided with a piercing portion having asharp point 12 which enters the tissue of a patients finger when the lancet is being used. The piercing portion uniformly increases in width from.point 12 and merges in ashoulder 13 having two reversedsections 13a and 13b of the same shape symmetrically positioned with respect to the longitudinal axis of the lam cet. The function of the shoulders is to restrict the dis tance that the piercing portion may be inserted in a finger and the piercing .portion length may Obviously vary depending on lancet use. v

Theshoulder 13 is of substantially the same shape as an equilateral triangle, one point of the triangle being directed opposite to thepoint 12 and which merges into a grip portion or handle 14. As shown, thehandle 14 increases in width in the direction of the handlefree end 15 which is rounded to provide a pressure surface orarea 16 against which a persons finger may be chine cycled for a first stamping operation, the lancet 1 la is first stamped out. The previously stampedlancet 11 is then detached from the strip although in the usual operation, the cut will be clean and the lancet will fall into a collecting bin.

As the strip steel is fed into the machine for the next cut and again cycled, thelancet 11d is stamped out and thelancet 11c detached, and so on, until the strip is exhausted. It will be noted that two lancets are formed by each stamping operation, thus doubling the speed of production over prior methods. Further, the design of the lancet has been chosen to utilize to the maximum extent, all the material in the steel strip. Reference to FIG. I shows that the only material wastage is that small amount between thepressure surface 16 and the edge of the strip.

Consideration of the lancet design and the manufacturing process used in forming the lancet shows that substantial savings in material over prior art designs has been achieved. This saving coupled with doubling the lancet production speed has resulted in an overall cost reduction of approximately 50 percent.

In the embodiment of FIG. 1, the lancets are stamped from strips having substantially the same width as the entire length of each lancet, one lancet being positioned in one direction and the adjacent lancet being positioned in the opposite direction, with the sections of the shoulder of one lancet being formed by the corresponding recesses in the adjacent lancets.

In the modification of FIG. 2, the lancets are manufactured by being stamped from strips having substantially the same width as the maximum width of the grip portion or handle, one lancet being positioned in one direction and the adjacent lancet being positioned in the opposite direction, and the shoulder of each lancet being formed by a corresponding recess in the handle of the adjacent lancet.

In FIG. 2, twolancets 21a and 21b are stamped from the strip in a single operation. As is evident, the width of the strip equals the greatest width of each of the lancets.

Each lancet comprises apiercing portion 22 which merges into asingle shoulder 23 asymmetrically positioned on one side of the lancet. Theshoulder 23, which is substantially triangular in shape, continues into the grip portion or handle 24 of the lancet. The width of the handle increases in the direction of thefree end 25 and is rounded to provide apressure surface 26. Arecess 27 having the same configuration as theshoulder 23 is formed in thefree end 25 of the handle. As in the preferred embodiment, thestrip 20 is provided with twostiffening depressions 28 to impart strength and rigidityto the lancet.

In the manufacturing operation, thesection 30a is first separated from the strip to form thepressure surface 26 on thelancet 21a. Thestrip 20 is fed forward along the length of one lancet and is cut at 31 to separate the twolancets 21a and 21b from each other. Thesection 30b is then stamped out either during the same operation when cut 31 is made or in a separate operation. Upon separation of the two lancets, each will be provided withsharp points 22 as a result of cutting along the length and into the edge of the strip material.

In view of the above, it will be apparent that many modifications and variations are possible in light of the above teachings. It therefore is to be understood that within the scope of the appended claims, the invention may be practised other than as specifically described.

What I claim as new and desire to secure by United States Letters Patent is:

1. A method of manufacturing a lancet of the type having a piercing portion on one end of a steel strip and a shoulder integrally formed therewith and extending outwardly and perpendicularly to the lancet longitudinal axis, said lancet further being of the type having a handle connected with said shoulder and gradually increasing in width toward the other end of said strip, a pressure surface on said other end, and recesses adjacent said other end which are complementary to said shoulder, comprising the steps of:

stamping lancets from a steel strip having substantially the same width as the entire length of each lancet, and wherein alternate lancets are positioned with the piercing portion in one direction and the lancets adjacent said alternate lancets are positioned with the piercing portion in the opposite direction, and the shoulder of one lancet being formed by corresponding recesses in an adjacent lancet, each stamping line defining one side edge of each of two adjacent and oppositely directed lancets, each stamping line having a portion defining one side edge of the piercing portion of one of the adjacent lancets and a portion of one side edge of the handle of the other lancet, a portion defining one side edge of the shoulder of one of the lancets and a recess in the handle of the other lancet, a portion defining a portion of one side edge of the handles of each lancet, a portion defining a recess in the handle of one of the adjacent lancets and one side edge of the shoulder in the other lancet, and a portion of one side edge of the handle of one lancet and a portion defining one side edge of the piercing portion of the other lancet.

2. A method of manufacturing a lancet of the type having a piercing portion on one end of a steel strip and a shoulder integrally formed therewith and extending outwardly and perpendicularly to the lancet longitudinal axis, said lancet further being of the type having a handle connected with said shoulderand gradually increasing in width toward the other end of said strip, a pressure surface on said other end, and recesses adjacent said other end which are complementary to said shoulder, comprising the steps of:

stamping lancets from a strip of stainless steel having substantially the same width as the maximum width of said handle, and wherein alternate lancets are positioned in one direction and lancets adjacent said alternate lancets are positioned in the opposite direction, and the shoulder of one of said lancets being formed by a corresponding recess in the handle of the other lancet, each stamping line defining one side edge of each of two adjacent and oppositely directed lancets, each stamping line having a portion defining one side edge of the piercing portion of one of the adjacent lancets and a portion of one side edge of the handle of the other lancet, a portion defining one side edge of the shoulder of one of the lancets and a recess in the handle of the other lancet, a portion defining a portion of one side edge of the handles of each lancet, a portion defining a recess in the handle of one of the adjacent lancets and one side edge of the shoulder in the pressure surface of an individual lancet.

4. The method of claim 1 further comprising the steps of providing each lancet with a stiffening depression and stamping a portion of the steel strip to define the pressure surface of a lancet prior to the step of stamping that lancet from the steel strip.

Claims (4)

1. A method of manufacturing a lancet of the type having a piercing portion on one end of a steel strip and a shoulder integrally formed therewith and extending outwardly and perpendicularly to the lancet longitudinal axis, said lancet further being of the type having a handle connected with said shoulder and gradually increasing in width toward the other end of said strip, a pressure surface on said other end, and recesses adjacent said other end which are complementary to said shoulder, comprising the steps of: stamping lancets from a steel strip having substantially the same width as the entire length of each lancet, and wherein alternate lancets are positioned with the piercing portion in one direction and the lancets adjacent said alternate lancets are positioned with the piercing portion in the opposite direction, and the shoulder of one lancet being formed by corresponding recesses in an adjacent lancet, each stamping line defining one side edge oF each of two adjacent and oppositely directed lancets, each stamping line having a portion defining one side edge of the piercing portion of one of the adjacent lancets and a portion of one side edge of the handle of the other lancet, a portion defining one side edge of the shoulder of one of the lancets and a recess in the handle of the other lancet, a portion defining a portion of one side edge of the handles of each lancet, a portion defining a recess in the handle of one of the adjacent lancets and one side edge of the shoulder in the other lancet, and a portion of one side edge of the handle of one lancet and a portion defining one side edge of the piercing portion of the other lancet.

2. A method of manufacturing a lancet of the type having a piercing portion on one end of a steel strip and a shoulder integrally formed therewith and extending outwardly and perpendicularly to the lancet longitudinal axis, said lancet further being of the type having a handle connected with said shoulder and gradually increasing in width toward the other end of said strip, a pressure surface on said other end, and recesses adjacent said other end which are complementary to said shoulder, comprising the steps of: stamping lancets from a strip of stainless steel having substantially the same width as the maximum width of said handle, and wherein alternate lancets are positioned in one direction and lancets adjacent said alternate lancets are positioned in the opposite direction, and the shoulder of one of said lancets being formed by a corresponding recess in the handle of the other lancet, each stamping line defining one side edge of each of two adjacent and oppositely directed lancets, each stamping line having a portion defining one side edge of the piercing portion of one of the adjacent lancets and a portion of one side edge of the handle of the other lancet, a portion defining one side edge of the shoulder of one of the lancets and a recess in the handle of the other lancet, a portion defining a portion of one side edge of the handles of each lancet, a portion defining a recess in the handle of one of the adjacent lancets and one side edge of the shoulder in the other lancet, and a portion of one side edge of the handle of one lancet and a portion defining one side edge of the piercing portion of the other lancet.

3. The method of claim 2 further comprising the steps of providing each lancet with a stiffening depression and stamping a portion of the steel strip to define the pressure surface of an individual lancet.

4. The method of claim 1 further comprising the steps of providing each lancet with a stiffening depression and stamping a portion of the steel strip to define the pressure surface of a lancet prior to the step of stamping that lancet from the steel strip.

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