Spring-loaded device for eliciting deep tendon reflexes

Abstract

A deep tendon reflex-eliciting device actuated by pressure against a patient's skin, which releases a spring-loaded mass that delivers an impulse through a fully-enclosed housing. This device includes a weight contained within the casings, and a mainspring in communication with the weight. The mainspring has a bias toward expansion. In the compressed position, the mainspring is also compressed, and the weight is pushed backwards into the rear casing. The weight is released to be driven forward by the mainspring. The weight strikes the inside of the forward casing, delivering an impulse to a surface against which the device is pressed. A reset spring can push apart the forward and rear casings to reset the device to its expanded position. A case screw is also included which is able to consistently set the impact force of the device.

Claims

1. A device for assessing reflexes in a subject, comprising: a forward casing mechanically coupled to a rear casing; a weight disposed between the forward casing and the rear casing; a mainspring translatably disposed within the rear casing, the mainspring having a first end that is secured to a rear lateral interior surface of the rear casing and a second end that is secured to the weight, such that the weight is biased by the mainspring in a direction away from the rear lateral interior surface of the rear casing, wherein in a resting configuration, the mainspring is decompressed, such that the weight is spaced apart from the forward casing, wherein in an intermediary configuration, the mainspring is compressed, such that the weight is disposed proximate to the rear interior surface of the rear casing, wherein in an activated configuration, the mainspring is decompressed, such that the weight contacts the forward casing, and wherein in the activated configuration, the device is configured to contact a subject and assess a reflex via the forward casing and the weight.

2. The device of claim 1, wherein the forward casing is received within the rear casing.

3. The device of claim 1, further comprising an assembly channel formed within an exterior sidewall of the forward casing.

4. The device of claim 3, further comprising an assembly tab formed within an exterior sidewall of the rear casing, the assembly tab being slidably received within assembly channel.

5. The device of claim 1, further comprising a forward elongated extension disposed within the forward casing and in mechanical communication with the weight, the forward elongated extension secured to a forward lateral interior surface of the forward casing and being spaced apart from one or more internal sidewalls of the forward casing.

6. The device of claim 5, further comprising a rear elongated extension disposed within the rear casing, the rear elongated extension secured to the rear lateral interior surface of the rear casing and being spaced apart from one or more internal sidewalls of the rear casing.

7. The device of claim 6, wherein the rear elongated extension is sized and shaped to contact the forward elongated extension in the activated configuration to separate the forward elongated extension from the weight.

8. The device of claim 6, wherein the forward elongated extension is substantially aligned with the rear elongated extension.

9. The device of claim 1, further comprising a first forward elongated extension and a second forward elongated extension, each of the first and second forward elongated extensions: disposed within the forward casing and in mechanical communication with the weight; secured to a forward lateral interior surface of the forward casing; and spaced apart from an internal sidewall of the forward casing, wherein the first and second forward elongated extensions are symmetrically and opposingly disposed within the forward casing.

10. The device of claim 9, further comprising a first rear elongated extension and a second rear elongated extension, each of the first and second rear elongated extensions: secured to the rear lateral interior surface of the rear casing; and spaced apart from an internal sidewall of the rear casing, wherein the first and second rear elongated extensions are symmetrically and opposingly disposed within the rear casing.

11. The device of claim 10, wherein each of the first and second rear elongated extensions is sized and shaped to contact one of the first and second forward elongated extensions in the activated configuration to separate the first and second forward elongated extensions from the weight.

12. The device of claim 10, wherein the first forward elongated extension is substantially aligned with the first rear elongated extension, and wherein the second forward elongated extension is substantially aligned with the second rear elongated extension.

13. The device of claim 1, further comprising an exterior contact surface disposed at a front end of the forward casing, the front end of the forward casing being opposite the rear lateral interior surface of the rear casing, the contact surface being at least partially made of an elastomer.

14. The device of claim 1, further comprising a reset spring guide at least partially disposed within the rear casing, the reset spring guide secured at a first end to the rear interior surface of the rear casing and terminating at a second end that is disposed between the rear lateral interior surface of the rear casing and a forward lateral interior surface of the forward casing, the second end including a reset tab that extends laterally toward at least one sidewall of the rear casing.

15. The device of claim 14, further comprising a reset spring disposed within the reset spring guide, the reset spring secured at a first end to the rear lateral interior surface of the rear casing and terminating at a second end.

16. The device of claim 15, further comprising a channel formed within the weight, wherein the reset spring is disposed through the channel formed within the weight.

17. The device of claim 15, further comprising a reset spring support disposed within the forward casing, the reset spring support having a first end that is secured to the forward lateral interior surface of the forward casing and a second end that is in mechanical communication with at least one of the reset spring and the reset spring guide.

18. The device of claim 17, wherein: in the resting configuration, the reset spring is decompressed, such that the rear lateral interior surface of the rear casing and the forward lateral interior surface of the forward casing are spaced apart by a first distance, and the reset tab is in mechanical communication with the weight, in the activated configuration, the reset spring is compressed, such that the rear lateral interior surface of the rear casing and the forward lateral interior surface of the forward casing are spaced apart by a second distance, the second distance being less than the first distance, and the reset tab is detached from the weight, and wherein in the absence of a force on the forward casing, the reset spring decompresses to translate the reset spring support in a direction away from the rear lateral interior surface of the rear casing, and the reset tab mechanically couples to the weight to return to the resting configuration.

19. The device of claim 1, further comprising an adjustable tensioning device in mechanical communication with the mainspring, such that the adjustable tensioning device is configured to adjust a tension of the mainspring in the resting configuration, such that an amount of mechanical energy stored within the mainspring during compression can be adjusted.

20. The device of claim 19, wherein the adjustable tensioning device is a case screw.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a fuller understanding of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which:

(2) FIG. 1 is an isometric perspective view of a reflex testing device, according to an embodiment of the current invention.

(3) FIG. 2 is an exploded perspective view of the reflex testing device of FIG. 1.

(4) FIG. 3 is an elevated cross-sectional view of a forward casing of the reflex testing device of FIG. 1.

(5) FIG. 4 is an elevated cross-sectional view of a rear casing of the reflex testing device of FIG. 1.

(6) FIGS. 5A, 5B, and 5C are elevated cross-sectional views of a reflex testing device in various stages of use, according to an embodiment of the current invention. FIG. 5A depicts the reflex testing device in a resting position. FIG. 5B depicts the reflex testing device under compression. FIG. 5C depicts the reflex testing device in a position after release.

(7) FIGS. 6A and 6B depicts use of a reflex testing device against a patient's knee, according to an embodiment of the current invention. FIG. 6A depicts the reflex testing device in a resting position. FIG. 6B depicts the reflex testing device under compression and/or after release.

(8) FIGS. 7A and 7B depict an embodiment with an adjustable variant of the device.

DETAILED DESCRIPTION

(9) In the following detailed description, reference is made to the accompanying drawings, which form a part thereof, and within which are shown by way of illustration specific embodiments by which the invention may be practiced. It is to be understood that other embodiments may be used, and structural changes may be made without departing from the scope of the present application. These embodiments are described in sufficient detail to enable those of ordinary skill in the art to practice the present disclosure, and it is to be understood that other embodiments may be utilized, and that structural, logical, and electrical changes may be made within the scope of the disclosure.

(10) From the following descriptions, it should be understood that components of the embodiments as generally described and illustrated in the figures herein could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of various embodiments, as represented in the figures, is not intended to limit the scope of the disclosure but is merely representative of various embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

(11) The following description provides specific details, such as material types, compositions, material thicknesses, and processing conditions in order to provide a thorough description of embodiments of the disclosure. However, a person of ordinary skill in the art will understand that the embodiments of the disclosure may be practiced without employing these specific details. Indeed, the embodiments of the disclosure may be practiced in conjunction with conventional techniques employed in the industry. Only those process acts and structures necessary to understand the embodiments of the disclosure are described in detail below. A person of ordinary skill in the art will understand that some process components are inherently disclosed herein and that adding various conventional process components and acts would be in accord with the disclosure. In this description, specific implementations are shown and described only as examples and should not be construed as the only way to implement the present disclosure unless specified otherwise herein.

(12) Illustrations presented herein are not meant to be actual views of any particular material, component, or system, but are merely idealized representations that are employed to describe embodiments of the disclosure. Referring in general to the following description and accompanying drawings, various embodiments of the present disclosure are illustrated to show its structure and method of operation. Common elements of the illustrated embodiments may be designated with similar reference numerals. It should be understood that the figures presented are not meant to be illustrative of actual views of any particular portion of the actual structure or method but are merely idealized representations employed to more clearly and fully depict the present invention defined by the claims below.

(13) It should be understood that any reference to an element herein using a designation such as first, second, and so forth does not limit the quantity or order of those elements, unless such limitation is explicitly stated. Rather, these designations may be used herein as a convenient method of distinguishing between two or more elements or instances of an element. Thus, a reference to first and second elements does not mean that only two elements may be employed there or that the first element must precede the second element in some manner. Also, unless stated otherwise a set of elements may comprise one or more elements.

(14) Any headings used herein should not be considered to limit the scope of embodiments of the invention as defined by the claims below and their legal equivalents. Concepts described in any specific heading are generally applicable in other sections throughout the entire specification.

(15) As used in this specification and the appended claims, the singular forms a, an, and the include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term or is generally employed in its sense including and/or unless the context clearly dictates otherwise.

(16) As used herein, about means approximately or nearly and in the context of a numerical value or range set forth means ?15% of the numerical. In an embodiment, the term about can include traditional rounding according to significant figures of the numerical value. In addition, the phrase about x to y includes about x to about y.

(17) It should be noted that ratios, concentrations, amounts, and other numerical data may be expressed herein in a range format. It is to be understood that such a range format is used for convenience and brevity, and thus, should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. To illustrate, a concentration range of about 0.1% to about 5% should be interpreted to include not only the explicitly recited concentration of about 0.1 wt % to about 5 wt %, but also include individual concentrations (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.5%, 1.1%, 2.2%, 3.3%, and 4.4%) within the indicated range.

(18) A pharmaceutically acceptable excipient, pharmaceutically acceptable diluent, pharmaceutically acceptable carrier, or pharmaceutically acceptable adjuvant means an excipient, diluent, carrier, and/or adjuvant that are useful in preparing a pharmaceutical composition that are generally safe, non-toxic and neither biologically nor otherwise undesirable, and include an excipient, diluent, carrier, and adjuvant that are acceptable for veterinary use and/or human pharmaceutical use. A pharmaceutically acceptable excipient, diluent, carrier and/or adjuvant as used in the specification and claims includes one or more such excipients, diluents, carriers, and adjuvants.

(19) The term therapeutically effective amount as used herein describes concentrations or amounts of components such as agents which are effective for producing an intended result. Compositions according to the instant application may be used to effect a favorable change in the underlying condition, whether that change is an improvement, relieving to some extent one or more of the symptoms of the condition being treated, and/or that amount that will prevent, to some extent, one or more of the symptoms of the condition that the host being treated has or is at risk of developing, or a complete cure of the disease or condition treated.

(20) As used herein, the term subject, patient, or organism includes humans and mammals (e.g., mice, rats, pigs, cats, dogs, and horses). Typical hosts to which an agent(s) of the present disclosure may be administered will be mammals, particularly primates, especially humans. For veterinary applications, a wide variety of subjects will be suitable, e.g., livestock such as cattle, sheep, goats, cows, swine, and the like; poultry such as chickens, ducks, geese, turkeys, and the like; and domesticated animals particularly pets such as dogs and cats. For diagnostic or research applications, a wide variety of mammals will be suitable subjects, including rodents (e.g., mice, rats, hamsters), rabbits, primates, and swine such as inbred pigs and the like.

(21) The phrases connected to and coupled to refer to any form of interaction between two or more entities, including mechanical, electrical, magnetic, electromagnetic, fluid, and thermal interaction. Two components may be connected or coupled to each other even though they are not in direct contact with each other. For example, two components may be coupled to each other through an intermediate component.

(22) The directional terms proximal and distal are used herein to refer to opposite locations on a medical device. The proximal end of the device is defined as the end of the device closest to the practitioner when the device is in use by the practitioner. The distal end is the end opposite the proximal end, along the longitudinal direction of the device, or the end furthest from the practitioner.

(23) Referring in general to the following description and accompanying drawings, various embodiments of the present disclosure are illustrated to show its structure and method of operation. Common elements of the illustrated embodiments may be designated with similar reference numerals. Accordingly, the relevant descriptions of such features apply equally to the features and related components among all the drawings. Any suitable combination of the features, and variations of the same, described with components illustrated in FIG. 1, can be employed with the components of FIG. 2, and vice versa. This pattern of disclosure applies equally to further embodiments depicted in subsequent figures and described hereinafter. It should be understood that the figures presented are not meant to be illustrative of actual views of any particular portion of the actual structure or method but are merely idealized representations employed to more clearly and fully depict the present invention defined by the claims below.

(24) All referenced publications are incorporated herein by reference in their entirety. Furthermore, where a definition or use of a term in a reference, which is incorporated by reference herein, is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.

(25) Reflex testing apparatuses and methods are provided. The apparatuses can be used to elicit deep tendon reflex responses from patients (animals and/or humans). In some embodiments, a mechanism on the handheld apparatus can allow a user to adjust an impulse in which the apparatus produces, and a source of potential energy can be used to produce a desired impulse. The ability to control the impulse produced by the apparatus, or provided by the method, can provide the user with an ability to determine hypo-, normo-, or hyper-reflexic physiologic states of patients with an increased degree of consistency.

(26) The use of a known mass impacting a tendon using some form of potential energy that gives the mass a velocity is provided. The end result, the impulse, can be pre-set and selected by the user, enabling him/her to quantify the DTR portion of the neurological assessment. This present disclosure is designed to enable the medical practitioner to objectively test DTRs by providing a consistent, measurable, and accurate impulse to a tendon.

(27) In some embodiments, the apparatus can entail a mechanism, not limited to a mechanism that creates an impulse, to which an impulse is elicited. This impulse can be controlled by an external dial or adjustment mechanism that can provide the user with the ability to control the amount of impulse produced by the device. The impulse can be elicited onto a firm hammer or mallet that with the intent of the hammer or mallet to contact a living human or animal tendon. By contacting the tendon with a known amount of impulse, the user can then observe the reflex response consistently. Depending on the amount of reflex elicited, the user can know if the subject, human or otherwise, has hypo-, normo- or hyper-reflexic DTRs.

(28) In some embodiments, an apparatus is provided apparatus for assessing reflexes of a patient's deep tendon, the apparatus comprising: an activatable hammer for contacting the patient's deep tendon when activated; a chamber for containing the activatable hammer; an impulse generator, in communication with the activatable hammer when inactive, for providing an impulse to the activatable hammer to activate the activatable hammer; a tuning mechanism, in communication with the impulse generator, for setting the impulse provided by the impulse generator to a predetermined strength; and an activation mechanism in communication with the impulse generator for releasing the impulse from the impulse generator thereby activating the hammer; wherein the reflexes of a patient's deep tendon are assessed by contacting the hammer to the patient's deep tendon and observing a reaction.

(29) In some embodiments, a method of assessing the reflexes of a patient's deep tendon is provided, the method comprising: providing an automated reflex hammer, as described herein, having a hammer mass; activating the release of the hammer mass from the automated reflex hammer proximate the individual's deep tendon; allowing the hammer mass to contact the individual's tendon with a hammering impulse to initiate at least one reflex; observing the individual's deep tendon reflexes; whereby the individual's deep tendon reflexes are assessed.

(30) The reflex testing apparatuses and methods provided can have multiple purposes, for example to decrease the inconsistency of the deep tendon reflex exam, to modify the kinematics of impulse delivery so as to reduce the physical space required to deliver the impulse allowing for accurate DTR assessments to be performed in spatially constrained areas, to quantify the impulse of the reflex test, and to provide for a means to best appreciate hypo-, normo-, and hyper-reflexive patients in the clinical setting.

(31) Deep tendon reflexes (here simply referred to as reflexes) are muscle contractions which occur in response to stretching within muscles. These reflexes are normally present uniformly within all of a person's limbs. In neurology, reflexes are used to quickly determine the location of injury to the nervous system.

(32) Reflexes are traditionally elicited by using reflex hammers. Reflex hammers are percussive devices used to strike at a tendon to induce sudden muscle stretching, which provokes a reflex response. Although many design variations of reflex hammer exist, the general principle of a hand-operated striking device is consistent among all of them. Reflex testing has the advantages of being fast, inexpensive, and noninvasive.

(33) Reflexes are tested on both sides of the body at five major sites. In the arm, these include the biceps reflex, at the inside of the elbow; the brachioradialis, at the forearm; and the triceps, at the outside of the elbow. In the leg, these include the patellar reflex, at the kneecap; and the Achilles, at the back of the ankle. Test results are quantified subjectively on a scale of 0 to 4+, where 2+ is a normal reflex response.

(34) Reflex testing can be limited under certain circumstances when a strike upon the tendon is obstructed. For example, an adequate reflex hammer swing may be impeded if a patient has a condition, such as contractures, which limit a patient's range of motion to a tense, closed position, giving insufficient room to swing a reflex hammer, particularly to test the biceps reflex. An adequate reflex hammer strike may also be impeded in cases of severe obesity, where parts of the patient's upper arm may physically block a reflex hammer from contacting the tendon site.

(35) Quantifiable testing for reflexes is also limited, as striking with a hand-operated hammer results in a different amount of force transmission with each strike. Additionally, the subjective scaling system for reflexes is based mainly on an examiner's experience, rather than quantifiable methods.

(36) A few mechanical devices for reflexes have been proposed to quantify reflexes in a reproducible fashion. In U.S. Pat. No. 2,800,895 to Torricelli, a number of spring-loaded reflex guns are proposed. These proposed devices deliver a consistent amount of force with each blow. However, they are triggered manually, and may be subject to variations in pressure when placing the device over the tendon. Additionally, each of these reflex guns uses an exposed striking surface, which may be obstructed from an adequate tendon strike in the scenarios described above.

(37) World Intellectual Property Organization patent 2017027954 to Synew Corp describes a spring-powered impulse generator with a mass traveling within a chamber before contacting tissue. The chamber may act as a shroud to prevent obstruction of the hammer mass by contracture. Synew Corp's design includes a manually-operated trigger, although the mechanism of trigger is not clearly defined. Their patent claims a tunable mechanism with adjustable spring tension but is still subject to variations in pressure when placing the device due to use of a manually-operated trigger. Synew's patent also claims various activation mechanisms to trigger the impulse generator, although the nature of these mechanisms and their relation to the impulse generator is not clearly defined.

(38) U.S. patents to Sweet, Spalding, and Adell and Starrett describe devices that release spring-loaded weights that drive weights forward. All of these devices are actuated by pressure upon a target surface. However, each of these devices uses a mechanism with multiple force-bearing surfaces contacting the released weight as well as the body of the device. These designs generate significant friction in operation, which limits their effectiveness in medical examination.

(39) The current invention is a device actuated by pressure against a patient's skin. The pressure releases a spring-loaded mass that delivers an impulse through a fully-enclosed housing to a tendon site on the patient. The impulse is intended to elicit a reflex from the patient. In certain embodiments, the device provides diagnostic advantages in conditions where a manual reflex hammer strike on a tendon is obstructed by a patient's limited range of motion or where the patient suffers from severe obesity.

(40) In certain embodiments, the current device includes a forward casing, a rear casing in communication with the forward casing, a weight contained within the casings, and a mainspring in communication with the weight. The mainspring has a bias toward expansion. In the resting position, the forward casing and the rear casing are separated or otherwise in an expanded disposition relative to each other. The casings may then be compressed together such that one casing overlaps the other substantially, and in this compressed position, the mainspring is also loaded. Maintaining the weight and mainspring in this position can be accomplished using any known mechanism. For example, the forward casing may contain a sear that holds the weight towards the end of the rear casing in preparation for release. When the sear is triggered by a ramp, the weight is released to be driven forward by the mainspring. The weight strikes the inside of the forward casing, delivering an impulse to a surface (e.g., skin) against which the device is pressed. To reset the device to its resting position, a reset spring can push apart the forward and rear casings. The weight can then be pulled back to its initial position by reset tabs attached to the rear casing.

ExampleStructure

(41) In an embodiment, as depicted in FIGS. 1-4, the current invention is a reflex testing device. The exterior of the device, which can be seen in FIG. 1, includes forward casing 1 and rear casing 2. Casings 1 and 2 are held together or otherwise coupled together via assembly tab 11, which slides within assembly channel 8. The interior of the device, which can be seen in FIG. 2, includes piston or weight 3. Weight 3 is enclosed within the casings 1 and 2 and slides within the interiors of casings 1 and 2 under the force of mainspring 5. Reset spring 4 is biased toward pushing apart (i.e., expanding) casings 1 and 2 and impinges upon forward and rear casings 1 and 2, respectively. Mainspring 5 impinges upon weight 3 and rear casing 2.

(42) FIG. 3 depicts a cross section of forward casing 1. An elastomer head 6 is secured at the front end of the forward casing 1. The elastomer head 6 may be composed of elastomers such as silicone or urethane rubber. A reset spring support 7 extends from the front end of the forward casing 1 towards the rear. Assembly channels 8 are present on the sides of the forward casing 1. The forward casing 1 contains sear 9 and wedge 10, which are affixed to one another. The sear 9 includes a support surface, which faces away from the elastomer head 6, and an inside surface, which faces towards the reset spring support. In this embodiment, the sear 9 and wedge 10 are integrated into the casing as part of a flexible structure. A hinge mechanism may also attach the sear and wedge to the forward casing 1. In this embodiment, assembly channels 8, sear 9, and wedge 10 are symmetrically present on both sides of the forward casing 1.

(43) FIG. 4 depicts a cross section of rear casing 2. Assembly tab 11 is integrated into the casing as part of its structure. Reset tab 13 is attached to the casing by spring guide 12, which forms a hollow tube shape. Ramp 14 is rigidly attached to the rear of the casing. In this embodiment, assembly tabs 11, reset tabs 13, and ramp 14 are symmetrically present on both sides of the rear casing 2.

ExampleOperation

(44) Reflexes are elicited using the device by pressing the elastomer head 6 against the patient's skin over a tendon/target site. Operation begins with the device in a resting position depicted in FIG. 5A, where reset spring 4 and mainspring 5 are in extended positions. When pressed against the patient's skin, the forward casing 1 is pushed backwards into the rear casing 2. The sear 9, attached to the forward casing 1, pushes upon the weight 3, compressing the mainspring 5 against the back of the rear casing 2. Reset spring support 7, also attached to the forward casing, compresses reset spring 4 into spring guide 12.

(45) The fully compressed state of the device is depicted in FIG. 5B, where reset spring 4 and mainspring 5 are in compressed positions. Continued pressure against the patient's skin pushes wedge 10 against ramp 14. The ramp 14 pries the wedge 10 and sear 9 outwards from weight 3. When pried outwards completely, the sear 9 releases the weight 3, which travels forward under spring power from mainspring 5 to strike the front of the forward casing 1. Momentum from the weight 3 travels through the forward casing 1 and elastomer head 6, such that a force is placed upon the patient's tendon, thus inducing a reflex from the patient.

(46) The released state of the device is depicted in FIG. 5C, where the reset spring 4 is in a compressed position and the mainspring 5 is in an expanded position. When the device is then withdrawn from the patient's skin, reset spring 4 pushes rear casing 2 backwards away from forward casing 1. Reset tab 13, attached to the rear casing by spring guide 12, is pulled backwards until it engages with weight 3. The weight 3 is dragged along the inner surface of sear 9 until it reaches the support surface, making it ready to be used again. The rear casing 2 is retained with the forward casing 1 by assembly tab 11, which stops against the end of the assembly channel 8.

(47) The use of the device is depicted in FIGS. 6A-6B. In FIG. 6A, the device is pressed against a patient's skin, and compressed until the weight is released. FIG. 6B depicts the device in the released state, after it has elicited a reflex. It can be understood that with the foregoing structure, the reflex testing device is capable of easily transferring stored momentum (i.e., stored within the mainspring 5) to the patient's tendon.

(48) FIGS. 7A and 7B depict one possible adjustable variant of the device, which provides variable strike force. An adjustable tensioning device, in this case screw 15 is added, which allows variable tension to be placed on mainspring 5. Stops may be positioned at the ends of screw threads to prevent the screw from backing out of either side of the rear casing 2. FIG. 7A shows the device with the screw 15 in the fully forward position. FIG. 7B shows the device with the screw 15 in a rearward position, which relieves tension on mainspring 5 and reduces strike force. The case screw 15 has markings so an end user is able to set the case screw 15 to the same position desired with increased accuracy.

(49) As described above, the embodiment depicted in FIGS. 7A and 7B has a reset spring 4, mainspring 5 which impinges on weight 3. The device has an elastomer head 6. The device has a reset spring support 7. The device also has assembly channels 8, sear 9, and wedge 10. The device further has an assembly tab 11, reset tab 13 attached to the casing by spring guide 12, which forms a hollow tube shape. Ramp 14 is rigidly attached to the rear of the casing.

(50) The advantages set forth above, and those made apparent from the foregoing description, are efficiently attained. While the disclosure is susceptible to various modifications and implementation in alternative forms, specific embodiments have been shown by way of non-limiting example in the drawings and have been described in detail herein. Since certain changes may be made in the above construction without departing from the scope of the instant application, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

(51) The disclosure is not intended to be limited to the particular forms disclosed. Rather, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure as defined by the following appended claims and their legal equivalents.

(52) Without further elaboration, it is believed that one skilled in the art can use the preceding description to utilize the present disclosure to its fullest extent. The examples and embodiments disclosed herein are to be construed as merely illustrative and exemplary and not a limitation of the scope of the present disclosure in any way. It will be apparent to those having skill in the art, and having the benefit of this disclosure, that changes may be made to the details of the above-described embodiments without departing from the underlying principles of the disclosure herein.

(53) It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention that, as a matter of language, might be said to fall therebetween.