WINDLASS PEN
20220047273 · 2022-02-17
Inventors
Cpc classification
B43K29/20
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
A tourniquet includes windlass having a cavity and a writing instrument configured to be stored in the cavity. The writing instrument is retained in the cavity through a friction fit and without threads, such that a frictional force decreases as the writing instrument is removed from the cavity.
Claims
1. A tourniquet to restrict a flow of blood in a limb, the tourniquet comprising: a strap for wrapping around a portion of a limb; a windlass for tightening the strap around the portion of the limb to suppress blood flow to and from that limb, the windlass having a cavity having an inner diameter and an interior wall; and a writing instrument adapted to be secured in part in the windlass cavity without threads, the writing instrument including: a shaft for containing a marking substance; a head, attached to the shaft, the head comprising a friction fit portion, the friction fit portion providing a non-localized friction fit with the inner wall of the windlass cavity; a standoff portion; and an end portion, separated from the end of the windlass by the standoff portion when the writing instrument is inserted into the windlass cavity, the end portion including a knurled surface for facilitating grip by a user to overcome the friction and remove the writing instrument from the windlass.
2. The tourniquet of claim 1, wherein friction fit portion includes a contact portion, the contact portion comprising ridges forming an interference fit with the cavity walls.
3. The tourniquet of claim 2, wherein the ridges are parallel to the long axis of the shaft.
4. The tourniquet of claim 1, wherein the friction fit portion includes a contact portion adapted to provide continuous friction as the contact portion is withdrawn from the windlass cavity.
5. The tourniquet of claim 1, wherein the friction fit portion includes a contact portion adapted to continue to provide friction as the writing instrument is withdrawn a distance of at least 3 mm from the windlass cavity.
6. The tourniquet of claim 1, wherein the friction fit portion includes a contact portion adapted to continue to provide friction as the writing instrument is withdrawn a distance of at least 6 mm from the windlass cavity.
7. The tourniquet of claim 2, wherein the ridges are concentric with the long axis of the shaft, the ridges forming an interference fit with the cavity walls.
8. The tourniquet of claim 1, wherein the friction fit portion includes a contact portion configured such that the friction between the contact portion and the interior wall of the windlass cavity decreases smoothly as the contact portion is pulled out from the windlass.
9. The tourniquet of claim 1, wherein the friction fit portion includes a contact portion configured such that the friction between the contact portion and the interior walls of the cavity of the windlass decreases in multiple incremental steps as the contact portion is pulled out from the windlass.
10. The tourniquet of claim 1, further comprising a restraining mechanism adapted for restraining the windlass after it has been tightened, the restraining mechanism including a clip and a restraining strap, the restraining strap having a surface that can be written upon by the writing instrument.
11. The tourniquet of claim 1, wherein the wherein the shaft contains a permanent and/or waterproof ink or other marking substance.
12. The tourniquet of claim 1, wherein the shaft contains a gel-type ink.
13. The tourniquet of claim 1, wherein: the belt includes an inner strap and an outer strap; and the windlass includes a slot through which the inner strap passes, the inner strap tightening as the windlass is wound.
14. A pen for inserting into a tourniquet windlass, comprising: a shaft for containing a marking substance; a head, attached to the shaft, the head comprising a friction fit portion, the friction fit portion providing a non-localized friction fit with the inner wall of the windlass cavity; a standoff portion; and an end portion, separated when the writing instrument is inserted into the windlass cavity from the end of the windlass by the standoff portion when the writing instrument is inserted into the windlass, the end portion including a knurled edge for facilitating grip by a user to overcome the friction and remove the writing instrument from the withdraw.
15. The pen of claim 14, wherein the pen comprises a gel-type ink.
16. The pen of claim 14, wherein the friction fit portion comprises ridges.
17. The pen of claim 16, wherein the shaft has a longitudinal axis and the ridges are parallel to the longitudinal axis.
18. A method of employing a tourniquet, comprising: providing a tourniquet having a writing implement wrapping the tourniquet around a limb; tightening the tourniquet using a windlass; securing the windlass to prevent it from unwinding; withdrawing a writing instrument from the end of the windlass by applying a force that decreases over a distance of at least 3 mm as the writing instrument is withdrawn from the windlass; writing the time that the tourniquet was applied to the limb on a portion of the tourniquet or elsewhere, in which withdrawing the writing instrument from the end of the windlass does not include unscrewing the writing instrument from threads in the windlass.
19. The method of claim 18 in which withdrawing a writing instrument from the end of the windlass by applying a force that decreases over a distance of at least 3 mm as the writing instrument is withdrawn from the windlass comprises withdrawing a writing instrument by applying a force that decreases smoothly after overcoming a static frictional force as the writing instrument is withdrawn.
20. The method of claim 18 in which withdrawing a writing instrument comprises applying a force that decreases over a distance of at least 5 mm as the writing instrument is withdrawn from the windlass.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0012]
[0013]
[0014]
[0015]
[0016]
[0017]
[0018]
[0019]
[0020]
[0021]
[0022]
[0023]
[0024]
[0025]
[0026]
DETAILED DESCRIPTION
[0027] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific implementations which may be practiced. These implementations are described in sufficient detail to enable those skilled in the art to practice the implementations, and it is to be understood that other implementations may be utilized and that logical, mechanical, electrical and other changes may be made without departing from the scope of the implementations. The following detailed description is, therefore, not to be taken in a limiting sense.
[0028] The detailed description is divided into three sections. In the first section, problems with the prior art are described. In the second section, apparatus of implementations are described. In the third section, implementations of methods are described. Finally, in the fourth section, a conclusion of the detailed description is provided.
Problems with the Prior Art
[0029] The systems of Hill and Burke et al. retain the writing instrument in the windlass using threads. That is, the pen screws into the windlass. Unscrewing the tourniquet pens of Hill and Burke from the windlass requires manual dexterity and multiple application of fine motor skills, which can be difficult to achieve in combat or other stressful situations. It is known that stress reduces dexterity and fine motor skills. See, for example, T. Cuper “Modeling the Effects of Stress: An Approach to Training,” https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20100012855.pdf, which states: “In the case of a combat medic, stress levels can be expected to be extremely high as the lives of both the medic and his comrades are at risk. In addition, the medic's performance requirements are complex, demanding both gross (e.g. running) and fine (e.g. applying a tourniquet, firing a weapon) motor skills as well as unaffected cognitive functioning. It is known that under stress, fine motor skills and dexterity can be greatly reduced.”
[0030] Moreover, the initial force to begin unscrewing the marking device varies with the torque applied when the marking device was last inserted. Tourniquets are typically applied to patients that are losing a great deal of blood, and the hands of the field medic or first aider are often slippery with blood. This can make it difficult to apply sufficient torque to unscrew the writing device from the windlass, particularly if the writing device was over torqued when it was last inserted.
[0031] A snap, such as described by Hill, requires a greater initial force to overcome the snap, which requires a tight user grip that may not be possible with the user's hand wet with blood and fine motor skills compromised by stress. Moreover, if the pen is inadvertently snagged by something in the environment, such as dense vegetation, the pen can move sufficiently far to overcome the snap. Once the localized snap force is overcome, there is nothing to prevent the pen from falling out of the windlass.
[0032] Tourniquets are typically used in the field, in conditions in which they are exposed to dirt, mud, and other contaminants. Such contaminates can clog threads and snaps, making it more difficult to remove the pen, especially under stressful conditions.
Apparatus Implementations
[0033] In this section, the particular apparatus of such an implementation are described by reference to a series of diagrams.
[0034]
[0035] To apply the tourniquet 100 to the limb, the user simply wraps the tourniquet around the subject appendage, loops the first end 120 of the belt 102 through the buckle 112, pulls the tourniquet 100 reasonably tight.
[0036] A windlass 106 includes a slot 122 through passes to the inner strap 104 as seen in
[0037] As shown in
[0038]
[0039]
[0040]
[0041]
[0042] In one implementation, ridges 712 are parallel to the axis of shaft 620 and evenly spaced circumferentially about smooth cylindrical portion 720 at 60 degrees from each other. Each of ridges 712 extends preferably between about 0.005″ and about 0.10″, above the smooth portion 710. Other configurations can be used, such as differently-shaped ridges or no ridges at all, in which the friction is provided between smooth cylindrical portion 720 and interior wall 508.
[0043] The frictional force required to remove writing instrument from cavity 506 depends on several factors, including the materials of which the ridges 712 and the interior wall 508 of cavity 506 are composed, the surface textures of the ridges and the interior wall of cavity 506, the contact area between the ridges and the inner surface of the cavity, and height of ridges 712 which defines the interference fit and determines the compression of the ridges. Additional ridges would increase the contact surface area, which would increase the friction. Skilled person can adjust the friction factors to produce a friction fit that is sufficient to secure the writing instrument 130 in windlass 122, but that permits removal of the writing instrument by a user having reduced dexterity due to stress and/or having hands wet and slippery with blood.
[0044] Ridges 712 preferably do not extend to the end of friction fit portion 704 from which the shaft 620 extends, but as described above provide for the gap 732 having a length 711 of preferably between about 0.01″ and about 0.10″, between the end of friction fit portion 704 from which shaft 620 extends and the beginning of ridges 712. The gap facilitates the insertion of the friction fit portion 704 into the cavity 506 of the windlass 106.
[0045] As the writing instrument is withdrawn, once the static friction is overcome, the friction decreases smoothly as the area of the ridges having contact with the cavity is reduced. The smooth reduction in friction makes it easier for a user having hands that are wet and slippery with blood to withdraw the writing instrument to write information on the retaining strap. Designing the friction fit portion 720 so that the friction reduces smooths eliminates the requirement for a large initial force, such as the force that would be required to overcome the resistance of a snap or detent.
[0046] With a snap or detent, there is a large initial force to overcome and then essentially no frictional force as the writing instrument is further withdrawn. In the embodiment of
[0047]
[0048]
[0049] Ridges 704, 804, 904, and 1004, referred to below ridges X04, preferably extend between about 0.01″ to 0.1″, preferably about 0.06″, above the major cylindrical surface of friction fit portion 710. When inserting the writing instrument into the interior cavity, the ridges are compressed slightly to maintain the writing instrument 130 within the interior cavity 506. The friction that keeps the writing instrument within the windlass cavity is determined by the materials of which the windlass and the ridges X04, as well as the number and geometry of the ridges. As the writing instrument is withdraw, the friction decreases in a relatively smooth manner as the contact area between the ridges and the interior wall of cavity 506 is reduced. The incremental reduction in friction makes it easier for a user having hands that are wet with blood to withdraw the writing instrument to write information on the retaining strap. Because the friction is spread amount the ridges, there is no initial large force needed to overcome.
[0050] In some implementations the writing instrument includes a ball point pen. The pen uses gel-type, waterproof, permanent ink or other marking substance. In some implementations, the windlass pen comprises a felt tip pen, a grease pencil, or a carbon pencil. The shaft is preferably made of copper or other material that will not rust or corrode. The writing substance may be stored within shaft 620.
[0051] The diameter of the standoff portion 622 is slightly larger than the inner diameter of the windlass cavity so that the stand-off portion will not go into the cavity 506, thereby preventing the writing instrument 130 from being inserted into the cavity 506 in windlass 106 up to the end 706. Keeping the end 706 positioned slightly way from the end of the windlass 106 facilitates grasping of the knurled end portion by a user.
[0052]
[0053]
[0054]
Method Implementations
[0055] The previous section describes an example of a tourniquet having a writing instrument configured to be stored in a windlass. In this section, the particular methods of such an implementation are described by reference to a series of flowcharts.
[0056]
[0057] Method 1500 includes in step 1505 wrapping the tourniquet 100 around the subject appendage and then step 1510 includes looping the first end 120 of the belt 102 through the buckle 112. The tourniquet 100 is pulled reasonably tight in step 1515.
[0058] Step 1520 includes winding the windlass 106 to develop a tension force to tighten inner strap 104 which tightens the belt 102. After the windlass 106 has been sufficiently tightened to restrict the arterial blood flow in the limb, the windlass 106 is inserted into windlass clip 302 in step 1525 to prevent inner belt 104 from unwinding. In step 1530, the opening in the windlass clip is covered with the retaining strap 108, which includes hook-and-loop fasteners that mate with the hook-and-loop fasteners on the windlass clip to prevent the windlass from coming out of the windlass clip.
[0059] In step 1535, writing instrument 130 is removed from windlass 106 and in step 1540, the protective substance is removed from the tip of the writing instrument. The protective substance can be removed by merely starting to write with the writing instrument, with the protective substance coming off as the writing instrument contacts and moves relative to the markable surface. In step 1545, a user records the time at which the tourniquet was applied and any additional notes. The time can be recorded on the tourniquet itself, such as on the restraining strap 304. Alternatively, the time can be recorded elsewhere, such as on the clothing or skin of the patient. In step 1550, writing instrument 130 is then discarded or temporarily reinserted into windlass 106. If writing instrument 130 is temporarily reinserted in windlass cavity 506, it should eventually be disposed of because with the protective substance removed, the ink or other marking substance may eventually dry and render the writing instrument unusable.
[0060] Although the description described a tourniquet with an inner and outer strap, the writing instrument can be used with a windlass of any type of tourniquet.
CONCLUSION
[0061] A tourniquet having a windlass that stores a writing instrument is described. Although specific implementations are illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement which is calculated to achieve the same purpose may be substituted for the specific implementations shown. This application is intended to cover any adaptations or variations. For example, although described in medical terms, one of ordinary skill in the art will appreciate that implementations can be used in industrial environments or any other environment that provides the required function.
[0062] In particular, one of skill in the art will readily appreciate that the names of the methods and apparatus are not intended to limit implementations. Furthermore, additional methods and apparatus can be added to the components, functions can be rearranged among the components, and new components to correspond to future enhancements and physical devices used in implementations can be introduced without departing from the scope of implementations. One of skill in the art will readily recognize that implementations are applicable to future tourniquet devices, different pens, and new buckles.
[0063] The terminology used in this application is meant to include all tourniquets, buckles, belts and connecting members and alternate technologies which provide the same functionality as described herein