Disposable vaginal speculum

Abstract

A two piece disposable vaginal speculum capable of full angular and elevational adjustment. The instrument comprises an upper and a lower blade connected together by a pin and slot connection to permit relative pivotal and sliding adjustment of the blades. To hold the blades in the desired adjusted position, one of them is formed with a pair of spaced, arcuate rows of ratchet teeth and the other is provided with a pawl selectively engageable with the teeth. The row of teeth in which the pawl is positioned determines the elevational adjustment of the blades while the particular tooth in the row that is engaged determines the angular adjustment.

Description

BACKGROUND OF THE INVENTION

This invention relates generally to surgical instruments, and has particular reference to a two piece vaginal speculum of novel construction. More specifically, the pieces of the speculum are molded plastic which permits the instrument to be economically manufactured and disposed of after use.

In the past, specula of the type with which the invention is concerned have been made of metal and intended for long use. This meant that the instrument had to be autoclaved after each use which is time consuming and, with ever increasing labor costs, expensive. More recently, therefore, the trend has been toward disposable or "throw away" type instruments of relatively inexpensive construction.

Disposable vaginal specula are disclosed in U.S. Pat. Nos. 3,528,409; 3,575,163; 3,650,266 and 3,716,047 which represent the closest prior art known to the applicants. The last patent listed, to W. C. Moore et al., is owned by the assignee of the present invention. In most of the disposable vaginal specula developed heretofore, there has been the problem that the lowest cost instruments have afforded less than the full range of adjustments permitted by the more expensive metal instruments and desired by the physicians, while the instruments that have all of the adjustment possibilities desired are not as low cost and the practicality of throwing them away after use becomes marginal.

SUMMARY OF THE INVENTION

The speculum of the present invention is capable of full angular and elevational adjustment and yet can be made at a cost low enough to warrant discarding it after use. The speculum comprises only two parts of molded non-toxic plastic material, the two parts essentially being an upper and a lower blade.

The blades are connected together by a pin and slot connection to permit relative pivotal and sliding adjustment. To releasably hold the blades in the desired adjusted position, one of them is formed with a pair of spaced, arcuate rows of ratchet teeth and the other is provided with a pawl selectively engageable with the teeth. The row of teeth in which the pawl is positioned determines the elevational or spatial adjustment of the blades while the particular tooth in the row that is engaged determines the angular adjustment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation of the disposable vaginal speculum of the invention with the blades in closed position;

FIG. 2 is a fragmentary side elevation of the speculum with the upper blade in elevated, full open position;

FIG. 3 is a partial sectional, partial side elevational view of the lower blade taken substantially on line 3--3 of FIG. 4;

FIG. 4 is a rear elevation of the lower blade;

FIG. 5 is a bottom plan view of the handle portion of the lower blade;

FIG. 6 is a fragmentary rear elevation of the upper blade;

FIG. 7 is a vertical section through the upper blade taken on line 7--7 of FIG. 6;

FIG. 7A is an enlarged transverse section through an upper blade pawl taken on line 7A--7A of FIG. 7;

FIG. 8 is an enlarged, fragmentary side elevation of the lower blade; and

FIGS. 9, 10 and 11 are fragmentary sectional views taken respectively on lines 9--9, 10--10 and 11--11 of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, and with specific reference to FIGS. 1-8, the disposable vaginal speculum of the invention is essentially comprised of an upper blade or bill 14 and a lower blade or bill 15 preferably of molded plastic material. The configuration of the blades per se is conventional, the blades shown being known as the Graves type in recognition of the physician who originally designed them. However, almost any blade configuration can be employed in carrying out the invention.

Formed integrally with the lower blade 15 are a pair of spaced, substantially parallel walls 16 which extend rearwardly and downwardly from the blade as shown. A depending handle portion 17 also is formed integrally with blade 15 and with the side walls 16, the handle portion being faired into the lower surface of the blade, FIGS. 1-3. Upper blade 14 also has a pair of spaced, substantially parallel walls 18 formed integrally therewith, the walls forming rearward and downward extensions of the blade.

As indicated in FIGS. 1 and 2, when the two blades are assembled, the upper blade walls 18 are disposed outside the lower blade walls 16 in close confronting relation thereto. Upper and lower blades are connected together by a pair of oppositely disposed pin and slot connections, the upper blade walls 18 having slots 20 into which lugs 21 on the lower blade project. The pin and slot connections permit relative pivotal and sliding adjustment of the blade as will be explained more fully hereinafter.

To releasably hold the blades in the desired adjusted position, each lower blade wall 16 is formed with a double row of ratchet teeth 22, FIGS. 1-3, 8 and 9, and each upper blade wall 18 is provided with an integral pawl 24 that is selectively engageable with the teeth in one of the rows, FIGS. 1, 6 and 7. The rows of ratchet teeth are spaced apart and slightly arcuate, and the degree of spacing between the blades, or elevational adjustment, depends upon whether the pawls 24 are positioned for engagement with the upper or the lower rows of teeth, compare FIGS. 1 and 2. When upper blade 14 is elevated as in FIG. 2, the pivot lugs 21 engage the lower ends of slots 20 whereas when the upper blade is in the lowered or non-elevated position, FIG. 1, lugs 21 engage the upper ends of slots 20.

Within the upper or lower ratchet tooth rows, the particular tooth 22 in the row that is engaged by its associated pawl 24 determines the angular adjustment of the blades. Thus, in FIG. 1 the blades are shown in solid lines in closed position, i.e. with no angular adjustment, and the pawls are behind the first or rearmost tooth in each lower row. Rotating the upper blade 14 about the lugs 21 results in the pawls engaging a particular pair of teeth and changes the angular adjustment of the blades as shown in phantom lines at 14'. Similar rotation of the upper blade in its elevated position, FIG. 2, results in substantially greater expansion of the cavity being examined.

To conveniently adjust the position of the upper blade 14, the lower rear corners of its spaced walls 18 are connected together by a yoke or bridging member 25, FIGS. 6 and 7, having a central serrated portion 26 adapted to be engaged by the user's thumb.

Referring again to the upper and lower rows of ratchet teeth 22, and with particular reference to the enlarged views of FIGS. 8-11, a feature of the invention is the manner in which these rows and the pawls 24 are formed and coact with each other. As best shown in FIGS. 8 and 9, directly above each row of teeth 22 there is an elongated opening 27 through the lower blade walls 16 in which opening the associated pawl 24 is located when engaging one of the teeth. To disengage the pawls, the upper blade 14 is pushed up a short distance by exerting thumb pressure on the underside of the serrated portion 26 of yoke 25.

As best shown in FIG. 6, the upper portions 28 of pawls 24 are bevelled and when blade 14 is pushed up these pawl surfaces ride up inclined surfaces 30 adjacent the upper edges of the elongated openings 27 until the lower edges of the pawls clear the tips of the ratchet teeth. As a result of this upward and slightly outward movement, the upper non-bevelled portions of the pawls are brought into engagement with non-inclined ledges 31 directly adjacent the upper edges of the openings.

When the lower edges of the pawls clear the tips of the ratchet teeth 22, upper blade 14 can be rotated to the desired new position of adjustment. Upon reaching this, the physician simply stops pressing up on the yoke 25 and the blade 14 moves down causing the pawls to engage the teeth that are below them, the downward movement and engagement being due to the external pressure that is experienced by the blades in this type of speculum. As best shown in FIGS. 8 and 11, the substantially vertical pawl holding edge 32 of each ratchet tooth is tapered rearwardly from the outside to the inside surface of the lower blade walls 16 and this taper or bevel operates to cam the engaging pawls inwardly. This in turn brings the upper walls 18 into closer engagement with the lower blade walls and provides a desirable self-locking feature. To aid in the camming action, each pawl 24 is provided with a mating taper or bevel as indicated at 24a in FIG. 7A.

To move the pawls 24 from the lower to upper rows of teeth and thereby move upper blade 14 to its elevated position, the blade is normally first rotated to closed position whereby the pawls are positioned behind the first or rearmost tooth in each row. From this position, upward pressure on the serrated portion of yoke 25 causes the pawls to slide up vertical recesses 34, FIGS. 8 and 10, connecting the rear ends of the tooth rows, the bottom of the recess in each lower blade wall lying in the same plane as the ledges 31 previously described.

If the pawls 24 are in the lower rows and positioned so that the upper blade is partially or all the way open, the pawls can be shifted directly to the upper rows without rotating the blade to closed position by simply pushing straight up on the yoke 25. This moves the pawls out of engagement with the teeth in the lower rows, up the inclined surfaces 30 above the lower rows and over the surfaces 35 between the lower inclined surfaces 30 and upper rows of teeth whereupon the pawls can spring into engagement with the teeth in the upper rows directly above those they had engaged in the lower rows. During such movement, the natural resiliency and relative thinness of the plastic material permits the upper blade walls 18 to be sprung outwardly enabling the pawls to pass over the intermediate surfaces 35. To facilitate this direct upward adjustment, the serrated portion 26 on the upper blade yoke 25 extends to the under side of the yoke as best shown in FIG. 7.

From the description thus far, it will be understood that the angular adjustment of the upper blade 14 can be controlled independently of its elevation and vice versa. Both adjustments, however, can be effected by moderate thumb pressure on the serrated portion of the yoke, this portion being comfortably positioned for the thumb when the handle portion 17 of the instrument is grasped by the physician.

In using the instrument of the invention, light for illuminating the area being examined may emanate from the physician's headlight, from a light unit connected to the handle 17 or other suitable source. To enhance good illumination regardless of source, the viewing passage through the instrument is substantially unobstructed. The instrument disclosed is constructed so that it may be used with a light unit (not shown) that can be removably attached to the handle 17, the unit being arranged to direct light substantially along the longitudinal axis of lower blade 15.

The handle portion 17, which is comfortable to hold with or without the light unit, is formed with reinforcing ribs 36 that provide for dovetail engagement with the light unit. As best shown in FIGS. 3 and 4, the lower blade is provided with a mucous wall or trap 37 to prevent fluids from running down the handle. Light from the light unit is directed over the top of this wall.

From the foregoing description, it will be apparent that the invention provides a novel disposable vaginal speculum that can be economically manufactured and yet has the full range of adjustments afforded by more expensive, permanent type instruments. As will be understood by those familiar with the art, the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

Claims

We claim:

1. A vaginal speculum comprising a pair of separable blades of resilient material fastened together by a pin and slot connection to permit relative pivotal and spatial adjustment of the blades, the pivotal adjustment permitting the blades to be moved between closed and various degrees of open positions, one of the blades having a double row of ratchet teeth positioned one above the other and the other blade having a pawl selectively engageable with the teeth in either of said rows, and means to enable the pawl to be moved from one row to the other while the blades are in an open position.

2. A speculum as defined in claim 1 wherein each of the blades has a pair of spaced side walls extending rearwardly and downwardly therefrom, each of the walls of said one blade having a double row of ratchet teeth and each of the walls of said other blade having a single pawl respectively engageable with either one of the double rows of teeth.

3. A speculum as defined in claim 2 wherein the spaced side walls of the blade having the pawls are connected at their lower extremities by a bridging portion adapted to be engaged by the thumb of the user to effect blade adjustment.

4. A speculum as defined in claim 2 including means interconnecting the rows of ratchet teeth in each blade wall to facilitate movement of the pawl on the confronting blade wall from one row to the other.

5. A speculum as defined in claim 2 wherein the pawl holding edge of each tooth in the ratchet teeth rows is tapered rearwardly from the outside to the inside surface of the blade walls in which the ratchet teeth rows are formed, and each pawl is formed with a mating taper, said tapers on the teeth acting on the tapers of the engaging pawls on the walls of the other blade to cam the two pairs of walls into close engagement with one another.

6. A speculum as defined in claim 1 wherein the means for enabling the pawl to be moved from one of the ratchet tooth rows to the other while the blades are in open position includes an inclined surface above the lower row of ratchet teeth and a bevelled surface on the upper portion of the pawl which surfaces coact to spring the pawl out of engagement with the lower row and permit its movement to the upper row.