Single-mass, one-dimensional resonant driver

Abstract

An efficiency-enhanced resonant system is provided with a backing mass connected to a linear vibrator, a parasitic mass connected to the linear vibrator, a positioning spring, a connecting device, and external biasing springs. The linear vibrator provides vibrating force to the parasitic mass which is connected to the connecting device, grasping a working implement. The use of separate positioning spring and external biasing springs accommodates a tuned system that balances the reduction in backing mass movement, avoids backing mass resonance within the working range of frequencies, and maintains a minimized linear vibrator stroke within the optimal range for one-dimensional implements within desired frequency ranges. The linear vibrator provides vibration that manifests as a frequency range of the natural frequency of the combined assembly of the parasitic mass, positioning spring, external biasing springs, connecting device, and implement, so that the resonant system efficiently performs work with minimized wasted energy.

Claims

1. A resonant system for operating an implement to perform work, and for being suspended from an external biasing force source, the resonant system comprising: a backing mass; a linear vibrator having a securement end and a movable end, the securement end of the linear vibrator being connected to the backing mass; a parasitic mass free to vibrate, the movable end of the linear vibrator being connected to the parasitic mass, the parasitic mass being connected to a connecting device for grasping and securing the implement; a positioning spring being connected to and between the backing mass and the parasitic mass, the positioning spring having a spring stiffness that facilitates achieving a frequency range of a natural frequency for a combined assembly; an external, flexible connection engaging the external biasing force source for suspending the resonant system and translating the external biasing force; a frame being connected to and suspended from the external, flexible connection; at least one external biasing spring being connected to and between the linear vibrator and the frame; the combined assembly comprising the parasitic mass, the positioning spring, each external biasing spring, the connecting device, and the implement; and wherein the linear vibrator delivers vibrations at the frequency range of the natural frequency for the combined assembly.

2. The resonant system of claim 1 wherein the linear vibrator comprises a piston/cylinder assembly, the piston/cylinder assembly comprises a piston and a cylinder, the piston being connected to the securement end of the linear vibrator that fixedly attaches to the backing mass, the cylinder being connected to the movable end of the linear vibrator that fixedly attaches to the parasitic mass.

3. The resonant system of claim 1 wherein the linear vibrator comprises a piston/cylinder assembly, the piston/cylinder assembly comprises a piston and a cylinder, the cylinder being connected to the securement end of the linear vibrator that fixedly attaches to the backing mass, the piston being connected to the movable end of the linear vibrator that fixedly attaches to the parasitic mass.

4. The resonant system of claim 1 wherein the external, flexible connection is not attached to the backing mass.

5. The resonant system of claim 1 wherein the resonant system is tunable to the frequency range of the natural frequency for the combined assembly by adjusting the spring stiffness of the positioning spring such that the frequency range delivered by the linear vibrator accommodates a size of the implement and a size and capability of the external biasing force source for movement and driving of the implement.

6. A resonant system for operating an implement to perform work, and for being suspended from an external biasing force source, the resonant system comprising: a backing mass; a linear vibrator, the linear vibrator comprises a piston/cylinder assembly, the piston/cylinder assembly comprises a piston and a cylinder, the piston being fixedly attached to the backing mass, the piston and cylinder defining an upper pressure chamber and a lower pressure chamber; a parasitic mass free to vibrate, the cylinder being movable and being connected to the parasitic mass, the parasitic mass being connected to a connecting device for grasping and securing the implement; a positioning spring being connected to and between the backing mass and either of the cylinder and the parasitic mass. the positioning spring having a spring stiffness that facilitates achieving a frequency range of a natural frequency for a combined assembly; an external, flexible connection engaging the external biasing force source for suspending the resonant system and translating the external biasing force, the external, flexible connection is not attached to the backing mass; a frame being connected to and suspended from the external, flexible connection; at least two external biasing springs each being connected to and between the frame and either of the cylinder or the parasitic mass; the combined assembly comprising the parasitic mass, the positioning spring, each external biasing spring, the connecting device, and the implement and wherein the linear vibrator delivers vibrations at the frequency range of the natural frequency for the combined assembly.

7. The resonant system of claim 6 further comprising a fluid medium disposed within the upper pressure chamber and the lower pressure chamber.

8. The resonant system of claim 7 wherein movement of the cylinder relative to the piston causes the fluid medium to pressurize within the lower pressure chamber and the fluid medium to depressurize within the upper pressure chamber when the cylinder moves toward the backing mass and defines an upward displacement equal to the distance of the movement of the cylinder relative to the piston and lifting the parasitic mass.

9. The resonant system of claim 8 wherein the upward displacement of the cylinder relative to the piston results in a volume change of fluid medium in the lower pressure chamber of 10% to 20% from the beginning to the end of the upward displacement.

10. The resonant system of claim 7 wherein movement of the cylinder relative to the piston causes the fluid medium to pressurize within the upper pressure chamber and the fluid medium to depressurize within the lower pressure chamber when the cylinder moves away from the backing mass and defines a downward displacement equal to the distance of the movement of the cylinder relative to the piston and lowering the parasitic mass.

11. The resonant system of claim 10 wherein the downward displacement of the cylinder relative to the piston results in a volume change of fluid medium in the upper chamber of 10% to 20% from the beginning to the end of the upward displacement.

12. The resonant system of claim 6 wherein the resonant system is tunable to the frequency range of the natural frequency for the combined assembly by adjusting the spring stiffness of the positioning spring such that the frequency range delivered by the linear vibrator accommodates a size of the implement and a size and capability of the external biasing force source for movement and driving of the implement.

13. A resonant system for operating an implement to perform work, and for being suspended from an external biasing force source, the resonant system comprising: a backing mass; a linear vibrator, the linear vibrator comprises a piston/cylinder assembly, the piston/cylinder assembly comprises a piston and a cylinder, the cylinder being fixedly attached to the backing mass, the piston and cylinder defining an upper pressure chamber and a lower pressure chamber; a parasitic mass free to vibrate, the piston being movable and being connected to the parasitic mass, the parasitic mass being connected to a connecting device for grasping and securing the implement; a positioning spring being connected to and between the backing mass and either of the piston and the parasitic mass. the positioning spring having a spring stiffness that facilitates achieving a frequency range of a natural frequency for a combined assembly; an external, flexible connection engaging the external biasing force source for suspending the resonant system and translating the external biasing force, the external, flexible connection is not attached to the backing mass; a frame being connected to and suspended from the external, flexible connection; at least two external biasing springs each being connected to and between the frame and either of the piston or the parasitic mass; the combined assembly comprising the parasitic mass, the positioning spring, each external biasing spring, the connecting device, and the implement and wherein the linear vibrator delivers vibrations at the frequency range of the natural frequency for the combined assembly.

14. The resonant system of claim 13 further comprising a fluid medium disposed within the upper pressure chamber and the lower pressure chamber.

15. The resonant system of claim 14 wherein movement of the piston relative to the cylinder causes the fluid medium to pressurize within the lower pressure chamber and the fluid medium to depressurize within the upper pressure chamber when the piston moves toward the backing mass and defines an upward displacement equal to the distance of the movement of the piston relative to the cylinder and lifting the parasitic mass.

16. The resonant system of claim 15 wherein the upward displacement of the piston relative to the cylinder results in a volume change of fluid medium in the lower pressure chamber of 10% to 20% from the beginning to the end of the upward displacement.

17. The resonant system of claim 14 wherein movement of the piston relative to the cylinder causes the fluid medium to pressurize within the upper pressure chamber and the fluid medium to depressurize within the lower pressure chamber when the piston moves away from the backing mass and defines a downward displacement equal to the distance of the movement of the piston relative to the cylinder and lowering the parasitic mass.

18. The resonant system of claim 16 wherein the downward displacement of the piston relative to the cylinder results in a volume change of fluid medium in the upper pressure chamber of 10% to 20% from the beginning to the end of the upward displacement.

19. The resonant system of claim 13 wherein the resonant system is tunable to the frequency range of the natural frequency for the combined assembly by adjusting the spring stiffness of the positioning spring and adjusting the vibration frequency delivered by the linear vibrator to accommodate the size of the implement and the size and capability of the external biasing force source for movement and driving of the implement.

20. The resonant system of claim 19 wherein the resonant system comprises a single positioning spring and tuning to the frequency range of the natural frequency for the combined assembly comprises changing the stiffness of the single positioning spring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The exemplary embodiments of the present invention is described more fully hereinafter with reference to the accompanying drawings, in which one or more exemplary embodiments of the invention are shown. Like numbers used herein refer to like elements throughout. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are representative and are provided so that this disclosure will be operative, enabling, and complete. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalents thereof. Moreover, many embodiments, such as adaptations, variations, modifications, and equivalent arrangements, will be implicitly disclosed by the embodiments described herein and fall within the scope of the present invention.

(2) Understanding that these drawings depict only exemplary embodiments and are, therefore, not to be considered limiting of the invention's scope, the exemplary embodiments of the invention will be described with additional specificity and detail through use of the accompanying drawings in which:

(3) FIG. 1 is an elevation diagram of a schematic configuration of a current state of the art resonant system showing the system's main components, spring configuration, connector, and an exemplary pile;

(4) FIG. 2 is a side elevation diagram of a schematic configuration of an exemplary embodiment of a single-mass, two-spring resonant system of the present invention showing the exemplary system's main components, separate biasing springs, the connector, and an exemplary pile.

(5) FIG. 3 is a section diagram of the schematic configuration of a piston and cylinder resonant system showing the long stroke as required when using a single spring used for both functions of backing mass centralizing and external force biasing, depicting the result of downward force onto the flexible and backing mass.

(6) FIG. 4 is a section diagram of the schematic configuration of the piston and cylinder resonant system of FIG. 3 showing the return stroke as required when using a single spring used for both functions of backing mass centralizing and external force biasing, and depicting the result of an equivalent upward load creating opposite geometry within the resonant system.

(7) FIG. 5 depicts a section diagram of the schematic configuration of the piston and cylinder resonant system having a shorter stroke wherein the piston moves about the center of stroke as closely as possible as a result of using separate springs for internal (positioning) biasing and external (force) biasing.

REFERENCE NUMERALS

(8) resonant system 10 vibratory source or linear vibrator 12 backing mass 14 (internal, positional) biasing spring 16 parasitic mass 18 connection device 20 linear or one-dimensional implement 22 flexible connection 24 piston/cylinder assembly 26 piston 28 cylinder 30 distal tip 32 (external, force) biasing springs 34 biasing force F (directional arrows) external flexible connection 36 pressurized medium seals 38 upper pressure chamber 40 lower pressure chamber 42 hydraulic medium 44 frame 46

DETAILED DESCRIPTION

(9) The exemplary embodiments of the present disclosure will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. It will be readily understood that the components, and their equivalents, of the exemplary 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 the exemplary embodiments, as represented in the Figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of exemplary embodiments of this disclosure.

(10) Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. Unless otherwise expressly defined herein, such terms are intended to be given their broad ordinary and customary meaning not inconsistent with that applicable in the relevant industry and without restriction to any specific embodiment hereinafter described. As used herein, the article “a” is intended to include one or more items. Where only one item is intended, the term “one”, “single”, or similar language is used. When used herein to join a list of items, the term “or” denotes at least one of the items, but does not exclude a plurality of items of the list. Additionally, the terms “operator”, “user”, and “individual” may be used interchangeably herein unless otherwise made clear from the context of the description.

(11) The word “exemplary” is used exclusively herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

(12) In this application, the phrases “connected to”, “coupled to”, and “in communication with” refer to any form of interaction between two or more entities, including mechanical, capillary, electrical, magnetic, electromagnetic, pneumatic, hydraulic, fluidic, and thermal interactions.

(13) The phrases “attached to”, “secured to”, and “mounted to” refer to a form of mechanical coupling that restricts relative translation or rotation between the attached, secured, or mounted objects, respectively. The phrase “slidably attached to” refer to a form of mechanical coupling that permits relative translation, respectively, while restricting other relative motions. The phrase “attached directly to” refers to a form of securement in which the secured items are in direct contact and retained in that state of securement.

(14) The term “abutting” refers to items that are in direct physical contact with each other, although the items may not be attached together. The terms “grip” and “grasp” refer to items that are in direct physical contact with one of the items firmly holding the other. The term “integrally formed” refers to a body that is manufactured as a single piece, without requiring the assembly of constituent elements. Multiple elements may be integrally formed with each other, when attached directly to each other from a single work piece. Thus, elements that are “coupled to” each other may be formed together as a single piece.

(15) FIG. 1 (labeled as prior art) depicts a conventional state of the art resonant system 10 comprising a vibratory source 12, such as a linear vibrator 12, a backing mass 14, with a single, (connective and positional) biasing spring 16, a parasitic mass 18, a connection device 20 (such as a clamp, clevis, socket, threaded engagement, eye and pin assembly, and any other type of device known to connect a working implement to a vibrating mass), and a linear implement 22. The backing mass 14 is connected to a base machine, crane, back hoe, or any suitable suspension structure using a flexible connection 24, through which a push or pull may be exerted. Also attached to the backing mass 14 is the velocity, vibratory source, linear vibrator 12, comprising a piston-cylinder-style velocity source, vibratory mechanism, referred to herein as the piston/cylinder assembly 26. The backing mass 14 typically includes a manifold, protective housing, support mechanisms, and hydraulic easements that are not depicted specifically in the drawings so to simplify the description of the resonant system 10 and so not to obscure components pertinent to understanding the resonant system 10. Although the manifold, protective housing, support mechanisms, and hydraulic easements are not shown, they are known to those skilled in the art. Also, although the connection device 20 is represented schematically in the drawings, it should be understood that the connection device 20 should be interpreted as including any and all known structures that connect a working implement to a vibrating mass, including but not limited to a clamp, clevis, socket, threaded engagement, eye and pin assembly, and the like.

(16) The biasing spring 16 is connected to and between the backing mass 14 and the vibratory, parasitic mass 18. The vibratory source (such as a linear vibrator) 12 is also connected to and between the backing mass 14 and the parasitic mass 18. In turn, the parasitic mass 18 is connected to the connection device 20 which grasps and secures the one-dimensional implement 22 serving as a working implement such as a pile, drill tube, or the like. Plumbing or other control (such as hydraulic lines) may be connected through the base machine to the backing mass 14 as well.

(17) The linear vibrator 12 comprises a piston/cylinder assembly 26. Either of the piston 28 or cylinder 30 is attached to the backing mass 14 and considered “stationary” or “more stationary;” while the other of the piston 28 or cylinder 30 which is considered “movable” and is connected to the implement 22 via the parasitic mass 18. For example, if the cylinder 30 is attached to the backing mass 14 (as shown in FIG. 2), then the piston 28 moves up and down relative to the backing mass 14 and excites the parasitic mass 18, the connection device 20 and the implement 22. Alternatively, if the piston 28 is attached to the backing mass 14 (as shown in FIG. 5), then the cylinder 30 moves up and down relative to the backing mass 14 and excites the parasitic mass 18, the connection device 20 and the implement 22. It should be understood that either the piston 28 or the cylinder 30 of the piston/cylinder assembly 26 may be attached to the backing mass 14 and the other moves and excites the implement 22.

(18) FIG. 1 depicts the geometry and interaction of the main components of the single-mass resonant system 10. The interaction of the components governs the system's natural frequency and reaction to loads; and thus, the operation, tuning and efficiency of the system 10. The magnitude of the backing mass 14 and its relationship with the single, positional biasing spring's 16 stiffness influences the acceleration and displacement of the implement 22 and the backing mass 14 under vibration. Any movement of the backing mass 14 is at the expense of opposite movement of the combined assembly of the parasitic mass 18, connection device 20, and one-dimensional implement 22.

(19) It is the movement of the distal tip 32 of the one-dimensional implement 22 opposite to the backing mass 14 that achieves work (compaction, pile driving, or drilling, for example). Maximizing the backing mass 14 and minimizing the biasing spring's 16 stiffness will result in the maximum movement of the implement 22 and the least influence upon the pure real natural frequency of the combined assembly comprising the parasitic mass 18, connection device 20, and one-dimensional implement 22 and maintains the effectiveness of the available tuning systems. However, increasing the backing mass 14 of the equipment is undesirable, as it results in large, unwieldy equipment that is difficult and expensive to handle and maneuver during operation. Similarly, a weak biasing spring 16 will result in large displacements of the piston 28 or cylinder 30 during biasing of the mechanism during operation, where biasing refers to pushing, pulling or adding force to the direction of motion to enhance work.

(20) Users desire the smallest and lightest equipment possible in order to gain efficiency and ease of handling. This desire suggests minimizing the dominant, backing mass 14 and maximizing of the stiffness of the connective biasing spring 16. The reduction of the backing mass 14 and increasing the stiffness in the connective biasing spring 16 results in an increase in the contamination of the pure real natural frequency of the system, causing an increase in the backing mass 14 movement, which reduces the one-dimensional implement's 22 equal and opposite movement and work efficiency. In addition, a more flexible biasing spring 16 requires a longer working stroke of the piston/cylinder assembly 26 under biased operation.

(21) The single-mass, two-spring resonant system 10 of the invention, resolves the issues experienced with the known resonant systems 10 (shown in FIGS. 1, 3, and 4). FIG. 2 depicts an exemplary embodiment of a single-mass, two-spring resonant system 10 of the invention, comprising a linear vibrator 12, a backing mass 14, separate and distinct springs (namely, an internal (positional), biasing spring 16 and a pair of external biasing springs 34), and a connection device 20 for grasping and connecting to a linear implement 22. The backing mass 14 is attached to a linear-piston-cylinder-style, vibratory source 16. The positional biasing spring 16 is connected to and between the backing mass 14 and the parasitic mass 18. The vibratory source 12, such as a linear vibrator 12, is also connected to and between the backing mass 14 and the parasitic mass 18. The parasitic mass 18 is attached to the connection device 20 (e.g., a clamp) which grasps and secures the one-dimensional implement 22, that serves as a working implement such as a pile, drill tube, chisel, or the like. Each external biasing spring 34 is connected to and between the piston/cylinder, linear vibrator 12 (via the parasitic mass 18) and an external flexible connection 36 (hoisting hook or other) used to suspend the resonant system 10 and transfer a biasing force F. It should be noted that while flexible connection 24 connects to the backing mass 14, flexible connection 36 does not.

(22) FIG. 2 depicts the geometry and interaction of the main components of the single-mass, two-spring resonant system 10. The interaction of the components governs the system's natural frequency and reaction to loads; and thus, the operation, tuning and efficiency of the system 10. The magnitude of the backing mass 14 and its relationship with the stiffness of the single, positional biasing spring 16 influences the acceleration and displacement of the implement 22 and the backing mass 14 under vibration. Any movement of the backing mass 14 is at the expense of opposite movement of the combined assembly of the parasitic mass 18, connection device 20, and one-dimensional implement 22. It is the movement of the distal tip 32 of the one-dimensional implement 22 opposite to the backing mass 14 that achieves work (compaction, pile driving, or drilling, for example).

(23) As noted above, maximizing the backing mass 14 and minimizing the stiffness of the biasing spring 16 will result in the least influence upon the pure real natural frequency of the combined assembly of the parasitic mass 18, connection device 20, and one-dimensional implement 22 and maintains the effectiveness of the available tuning systems. Again, however, increasing the mass of the equipment is undesirable as it results in large, unwieldy equipment that is difficult and expensive to handle and maneuver during operation. In this exemplary embodiment, a weaker (i.e., less stiff) biasing spring 16 is permissible because no external biasing force F is to be translated into the backing mass 14. An exemplary positional biasing spring 16 with low stiffness allows for high isolation of the backing mass 14, and the least contamination of the pure real natural frequency of the combined assembly of the parasitic mass 18, connection 20, and implement 22. A soft (weaker, less stiff) positional biasing spring 16 will also minimize the transfer of the reciprocating force delivered by the piston/cylinder, linear vibrator 12 to the backing mass 14; and thus, maximize the force translated to the parasitic mass 18, connection 20 and implement 22. Stiff external force biasing springs 34 efficiently transfer biasing loads to increase production.

(24) Tuning of the dominant mass 14, biasing spring 16, vibratory source 12 to minimize the influence upon the combined vibratory, parasitic mass 18, connection device 20 and the expected or working range of one-dimensional implements 22 results in equipment optimized for the target use.

(25) The present embodiments indicate the separation of the internal (positional) biasing spring 16 and the external, biasing spring 34 will accommodate a tuned system that balances the reduction in backing mass 14 movement, avoids backing mass 14 resonance within the working range of frequencies, and maintains a minimized linear vibrator 12 stroke within the optimal range for one-dimensional implements 22 within desired frequency ranges.

(26) FIG. 3 (labeled as prior art) depicts a conventional linear oscillator system 10 using a single-biasing spring 16. The backing mass 14 is fixedly connected, in this example, to the linearly actuated piston 28. The linearly actuated cylinder 30 slidably engages piston 28 with pressurized medium seals 38 acting to enclose upper and lower pressure chambers 40, 42. The volumes of pressure chambers 40, 42 are expanded and contracted when external forces are exerted through the flexible connector 24 connected to the backing mass 14 and the biasing spring 16. Cylinder 30 is fixedly connected to the parasitic mass 18, the connector 20 and the implement 22.

(27) FIG. 3 also depicts the result of a downward force bias F onto flexible connector 24 and the backing mass 14 via some external means, for example a crane, a backhoe or a worker. The downward external force bias F results in translation of the piston 28 downward with respect to the cylinder 30 which resists movement due to the work required or external resistance upon the implement 22. The resulting translation of the piston 28 downward with respect to the cylinder 30 reduces the volume of the lower pressure chamber 42 and increases the volume of the upper pressure chamber 40.

(28) The reciprocating linear vibrator 12 now possesses uneven volumes in the upper 40 and lower 42 pressure chambers. Assuming for the purposes of this disclosure that the position of the piston 28 depicted in FIG. 3 reflects the end position of a downward stroke of the linear actuator 12 and the beginning of an upward stroke, pressurization of the upper chamber 40 has occurred and will begin to lift the cylinder 30 upwards, beginning an upward stroke. The currently depicted unpressurised hydraulic medium 44 within the upper pressure chamber 40 becomes pressurized as the cylinder 30 moves toward the end of the return stroke. The pressurized hydraulic medium 44 being introduced must compress the unpressurised hydraulic medium 44 within the upper chamber 40; and thus, will lose otherwise available stroke by an amount equal to the height of the upper chamber 40 multiplied by the pressure differential of the existing and introduced hydraulic medium 44, divided by the elastic modulus of the hydraulic medium 44.

(29) The compression of the fluid 44 represents wasted work which is unrecoverable as it is released upon evacuation of the fluid medium 44 at the end of the pressure stroke when the chamber vents to the return circuit. The energy is lost as heat which is inefficient. The subsequent cycle will translate the cylinder 30 downward by introducing pressurized hydraulic medium 44 into the lower pressure chamber 42. Note the lower pressure chamber 42 is significantly smaller in volume than the upper chamber 40, due to the downward external biasing force F, even following the last reciprocating cycle. The pressurized medium 44 must, similarly, compress the low pressure hydraulic medium 44 currently residing in the lower pressure chamber 42; and thus, will lose otherwise available stroke by an amount equal to the height of the lower chamber 42 multiplied by the pressure differential of the existing and introduced hydraulic medium 44, divided by the elastic modulus of the hydraulic medium 44. In this case, because the volume of the lower chamber 42 is smaller than the upper pressure chamber 42 less displacement will occur and thus less wasted work will occur during this compression. The result is that a reciprocating bias occurs with more translation of the cylinder 30 downward with each cycle that occurs on the subsequent upward cycle. The end of the upward cycle is depicted in FIG. 4.

(30) Similarly, during the next stroke further uneven work, stroke and losses will occur which must be accommodated for by the system 10. This unequal stroke and work may be accommodated in a number of ways but will result in additional wasted work and losses in the system 10.

(31) FIG. 4 (labeled as prior art) depicts that under an equivalent upward external biasing load, an equal but opposite geometry occurs with an equal but opposite loss built into the system 10 due to uneven stroke magnitude and work.

(32) FIG. 5 depicts another exemplary embodiment of the single-mass, two-spring resonant system 10 of the present invention, using two, separated biasing springs 34. The backing mass 14 is fixedly connected, in this exemplary embodiment, to the linearly actuated piston 28. The linearly actuated cylinder 30 slidably engages piston 28 with pressurized medium seals 38 acting to enclose upper and lower pressure chambers 40, 42. External forces are exerted through the flexible connector 36 connected to the external force biasing springs 34 via a frame 46 used to deliver the external biasing force F. As a result, the pressure chambers 40, 42 are not affected by the introduction of the external biasing force F upwards or downwards. Cylinder 30 is fixedly connected to the parasitic mass 18, the connector 20 and the implement 22.

(33) Of course, it should be understood that a differing geometry could be used in another exemplary embodiment. For example, the cylinder could be fixedly attached to the backing mass 14 and the piston 28 could be fixedly attached to the parasitic mass 18. Those skilled in the art will understand what affect this will have on the resonant system.

(34) FIG. 5 depicts the result of a downward force bias onto flexible connector 36 and the cylinder 30 via some external means (not shown), for example a crane, a backhoe or a worker. The downward external force bias F on flexible connector 36 results in a translation of the cylinder 30 downward with respect to the piston 28. However, positional biasing spring 16 reacts to the downward biasing translation by exerting a force downward on the backing mass 14 and equilibrates the force by translating the backing mass 14 downwards an appropriate distance to eliminate the biasing force F in the positional biasing spring 16 and slidably re-centering the piston 28 relative to the cylinder 30 to the center of stroke position. The resulting translation of the piston 28 downward with respect to the cylinder 30 maintains relatively equivalent volumes within the upper pressure chamber 40 and the lower pressure chamber 42.

(35) Further the external biasing of the resonant system 10 did not result in a change in stroke of the cylinder 30 slidably upon the piston 28 and thus did not change the upper 40 and lower 42 pressure chamber volumes. The stroke of the cylinder 30 slidably upon the piston 28 need only accommodate the reciprocating motion of the linear actuator 12 and not the combined motion of the linear actuator 12 and the biasing. As a result, the pressure chamber volumes may be made significantly shorter with less volume.

(36) The reciprocating linear vibrator 12 possesses smaller, more even volumes in the upper 40 and lower 42 pressure chambers. Assuming for the purposes of this disclosure that the position of the piston 28 depicted in FIG. 5 reflects the end position of a downward stroke of the linear actuator 12 and the beginning of an upward stroke. As depicted, pressurization of the upper chamber 40 has occurred and will begin to lift the cylinder 30 upwards, beginning an upward stroke. The currently depicted unpressurised hydraulic medium 44 within the upper pressure chamber 40 becomes pressurized as the cylinder 30 moves toward the end of the return stroke. The pressurized hydraulic medium 44 being introduced must compress the unpressurised hydraulic medium 44 within the upper chamber 40; and thus, will lose otherwise available stroke by an amount equal to the height of the upper chamber 40 multiplied by the pressure differential of the existing and introduced hydraulic medium 44, divided by the elastic modulus of the hydraulic medium 44.

(37) When the upper pressure chamber 40 volume is small, this loss is proportionally reduced and the linear actuator 12 is more efficient and delivers a longer stroke and conducts more work. The reciprocating work stroke is typically a fraction of the available pressure chamber stroke; and thus, the difference in the upper pressure chamber 40 volume and the lower pressure chamber 42 volume is small.

(38) The subsequent cycle will translate the cylinder 30 downward by introducing pressurized hydraulic medium 44 into the lower pressure chamber 42. Note, the lower pressure chamber 42 is now only slightly smaller in volume that the upper chamber 40, on the order of 10% to 20%, following the last reciprocating cycle. The pressurized medium 44 must, similarly, compress the low pressure hydraulic medium 44 currently residing in the lower pressure chamber 42; and thus, will lose otherwise available stroke by an amount equal to the height of the lower chamber 42 multiplied by the pressure differential of the existing and introduced hydraulic medium 44, divided by the elastic modulus of the hydraulic medium 44. In this case, because the volume of the lower chamber 42 has become only 10% to 20% smaller than the upper pressure chamber 40, only slightly more displacement will occur, which is easily made up by the positional biasing spring 16 or other means.

(39) FIG. 5 also depicts that under an equivalent upward external biasing load an equal but opposite geometry occurs.

(40) For exemplary methods or processes of the invention, the sequence and/or arrangement of steps described herein are illustrative and not restrictive. Accordingly, although steps of various processes or methods may be shown and described as being in a sequence or temporal arrangement, the steps of any such processes or methods are not limited to being carried out in any specific sequence or arrangement, absent an indication otherwise. Indeed, the steps in such processes or methods generally may be carried out in different sequences and arrangements while still falling within the scope of the present invention.

(41) Additionally, any references to advantages, benefits, unexpected results, preferred materials, or operability of the present invention are not intended as an affirmation that the invention has been previously reduced to practice or that any testing has been performed. Likewise, unless stated otherwise, use of verbs in the past tense (present perfect or preterit) is not intended to indicate or imply that the invention has been previously reduced to practice or that any testing has been performed.

(42) Exemplary embodiments of the present invention are described schematically above. No element, act, or instruction used in this description should be construed as important, necessary, critical, or essential to the invention unless explicitly described as such. Although only a few of the exemplary embodiments have been described schematically in detail herein, those skilled in the art will readily appreciate that schematic components are exemplary and representative of various known components that function similarly and that many modifications are possible in these exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the appended claims.

(43) In the claims, any means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. Unless the exact language “means for” (performing a particular function or step) is recited in the claims, a construction under Section 112 is not intended. Additionally, it is not intended that the scope of patent protection afforded the present invention be defined by reading into any claim a limitation found herein that does not explicitly appear in the claim itself.

(44) While specific embodiments and applications of the exemplary embodiments have been illustrated and described, it is to be understood that the invention is not limited to the precise configuration and components disclosed herein. Various modifications, changes, and variations which will be apparent to those skilled in the art may be made in the arrangement, operation, and details of the methods and systems of the present invention disclosed herein without departing from the spirit and scope of the invention.