Patent Publication Number: US-2022221019-A1

Title: Systems and devices for motion control

Description:
RELATED APPLICATIONS 
     The present application claims the benefit of, and priority to, U.S. Provisional Application No. 63/135,244, filed Jan. 8, 2021, titled “Systems and Devices for Motion Control.” The complete subject matter and contents of App. Ser. No. 63/135,244 are incorporated herein by reference in their entireties. 
    
    
     BACKGROUND 
     The slamming of a door can cause many problems. For instance, there is the risk that the door could be slammed on a person&#39;s fingers—often the fingers of a child. Additionally, slamming a door may result in a person or a pet being locked in a room. Moreover, nobody enjoys the loud sound of a slammed door. Besides the slamming of a door, there are numerous other situations, especially in industrial settings, where, if motion of an object is not adequately dampened or controlled, the motion can cause damage to equipment, harm to a person, and/or unpleasant noises. 
     SUMMARY 
     The systems and devices described herein utilize a Shear Thickening Fluid (STF) to allow a door to close normally when lighter pressure is applied during closure and to dampen, slow, and/or stop a door from slamming when greater pressure or speed is applied. STF is relaxed at rest and behaves nearly like most viscous liquids under minimal shear or pressure (e.g., flowable, pourable, etc.). Under normal closing conditions, the fluid remains relaxed and the door closes easily. When pressure or shear forces are applied, the fluid stiffens instantaneously, providing the functionality needed to work with devices described herein, which act to control the speed of a door or other devices. Adjustability of the amount of resistance has been designed into the devices as well. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of an example linear motion control system according to an embodiment of the present technology. 
         FIG. 2  is a cross-sectional side view of an example linear motion control system according to an embodiment of the present technology. 
         FIGS. 3A and 3B  are isometric views of an example linear motion control system according to an embodiment of the present technology. 
         FIG. 4A  is a top view of an example linear motion control system according to an embodiment of the present technology. 
         FIG. 4B  is a bottom view of an example linear motion control system according to an embodiment of the present technology. 
         FIG. 5A  is a side view of an example linear motion control system revealing internal components according to an embodiment of the present technology. 
         FIG. 5B  is an isometric view of an example linear motion control system revealing internal components according to an embodiment of the present technology. 
         FIG. 6  is an isometric view of an example adjustment knob of a linear motion control system according to an embodiment of the present technology. 
         FIG. 7A  shows an isometric view of an example piston head of a linear motion control system according to an embodiment of the present technology. 
         FIG. 7B  shows an isometric view of an example shim of a linear motion control system according to an embodiment of the present technology. 
         FIG. 8  is an isometric view of an example hinge pin assembly inserted into a hinge according to an embodiment of the present technology. 
         FIG. 9  illustrates a top view of example hinge pin assembly inserted into a hinge according to an embodiment of the present technology. 
         FIGS. 10 and 11  illustrate an example hinge pin assembly including a piston assembly, rebound shim, and piston cam according to an embodiment of the present technology. 
         FIGS. 12 and 13  illustrate an exploded view of an example hinge pin assembly according to an embodiment of the present technology. 
         FIGS. 14-18  illustrate an example chamber housing configured to contain movable parts of the hinge assembly according to an embodiment of the present technology. 
         FIGS. 19-24  illustrate an example piston assembly according to an embodiment of the present technology. 
         FIGS. 25-31  illustrate an example cam secured to a pin according to an embodiment of the present technology. 
         FIG. 32  is a side view of an example hinge system incorporated in a hinge according to an embodiment of the present technology. 
         FIG. 33  is a top view of an example hinge system incorporated in a hinge according to an embodiment of the present technology. 
         FIG. 34  provides a cross-sectional view of the inner mechanics of an example hinge assembly according to an embodiment of the present technology. 
         FIG. 35  provides an exploded view of an example hinge assembly and hinge according to an embodiment of the present technology. 
         FIG. 36  provides a cross-sectional view of the inner mechanics of an example hinge assembly according to an embodiment of the present technology. 
         FIG. 37  illustrates a view of an example plunger bushing according to an embodiment of the present technology 
         FIG. 38  illustrates a view of an example pin of an example hinge assembly according to an embodiment of the present technology. 
         FIGS. 39 and 40  illustrates a perspective view of an example closed hinge according to an embodiment of the present technology. 
         FIG. 41  illustrates a front view of an example hinge assembly and hinge according to an embodiment of the present technology. 
         FIG. 42  is a top view of an example hinge system and hinge according to an embodiment of the present technology. 
         FIG. 43  illustrates an example hinge assembly with mechanicals revealed according to an embodiment of the present technology. 
         FIG. 44  illustrates a cross-sectional view of an example hinge assembly with the mechanicals being partially revealed according to an embodiment of the present technology. 
         FIG. 45  illustrates a bottom view of an example hinge assembly and hinge according to an embodiment of the present technology. 
         FIG. 46  illustrate cross-sectional view of an example hinge assembly and hinge according to an embodiment of the present technology. 
         FIG. 47  illustrates a top view of an example hinge assembly and hinge according to an embodiment of the present technology. 
         FIGS. 48-51  illustrate multiple views of an example cap and mating lead screw nut according to an embodiment of the present technology. 
         FIGS. 52-54  illustrate multiple views of an example piston assembly and lead screw mechanism according to an embodiment of the present technology. 
         FIGS. 55 and 56  illustrate exploded views of an example piston assembly and lead screw mechanism according to an embodiment of the present technology. 
         FIGS. 57 and 58  illustrate perspective views of an example piston assembly, lead screw mechanism and plunger bushing according to an embodiment of the present technology. 
         FIGS. 59 and 60  illustrate cross-sectional views of an example piston assembly, lead screw mechanism and plunger bushing according to an embodiment of the present technology. 
         FIGS. 61-64  illustrate multiple views of an example piston assembly, lead screw mechanism and plunger bushing according to an embodiment of the present technology. 
         FIGS. 65-67  illustrate multiple views of an example a pin hinge shaft bottom according to an embodiment of the present technology. 
     
    
    
     The foregoing summary, as well as the following detailed description of certain embodiments of the present technology(s), will be better understood when read in conjunction with the appended drawings. 
     DETAILED DESCRIPTION 
     Systems and devices to control linear, rotational, and/or arcuate motion are disclosed herein. In disclosed examples, a pin system is configured for insertion in a door and/or door jamb, and to control motion of the door, such as a speed with which the door closes. In some disclosed examples, a hinge pin is configured to replace a conventional hinge pin and to control motion of the door. In some disclosed examples, a hinge system is configured to replace a conventional door hinge and to control motion of the door. For the purpose of illustrating the technology, there are shown in the attached drawings, certain embodiments of the systems. It should be understood, however, that the technology is not limited to the arrangements and instrumentalities shown in the drawings or to the descriptions of the embodiments herein. 
     In disclosed examples, a device for controlling the motion of an object, including a body that includes a chamber filled at least in part with a shear thickening fluid, a piston that is positioned in the body and that is connected to a cap, the piston configured to exert pressure against the shear thickening fluid in response to a force applied to the cap by an object, and a rod connected to the piston, the rod configured to adjust an amount of pressure exerted against the shear thickening fluid. 
     In some examples, the piston includes a plunger that is connected to a piston head. 
     In examples, a bushing to guide the cap and plunger into the chamber in response to the force applied to the cap. In examples, a spring that is configured to provide mechanical resistance between the cap and the bushing in response to the force applied to the cap. 
     In some examples, the shear thickening fluid comprises a plurality of nanoparticles. In examples, the plurality of nanoparticles comprises one or more of an oxide, calcium carbonate, synthetically occurring minerals, naturally occurring minerals, polymers, SiO 2 , polystyrene, polymethylmethacrylate, or a mixture thereof. 
     In some examples, the shear thickening fluid comprises a polymeric material. In some examples, the shear thickening fluid comprises one or more of ethylene glycol, polyethylene glycol, ethanol, silicon oils, phenyltrimethicone, or a mixture thereof. 
     In some examples, including a shim, wherein both the shim and the piston head include one or more slots. In examples, the one or more slots of the shim have a shape and size approximately equal to the one or more slots of the of the piston head. In examples, the shim is configured to rotate with respect to the piston head thereby adjusting the amount of resistance experienced by the piston. In examples, rotation of the shim to a first position substantially aligns the one or more slots of the shim with the one or more slots of the of the piston head, and rotation of the rebound shim to a second position substantially misaligns the one or more slots of the shim with the one or more slots of the of the piston head. 
     In some examples, the rod is connected to the shim and when the rod is rotated, the shim is rotated with respect to the piston head. In some examples, a knob that is located opposite the cap and that is connected to the rod, wherein the knob can be rotated to rotate the rod. In examples, the rod includes a generally D-shaped lip and the slot shim includes a generally D-shaped hole that receives the lip of the rod. In examples, the piston includes a plug that is received in the lip of the rod. 
     In disclosed examples, a device for controlling the motion of an object, includes a body that includes a chamber filled at least in part with a shear thickening fluid, a piston that is positioned in the body and that is connected to a cap, the piston configured to exert pressure against the shear thickening fluid in response to a force applied to the cap by an object, and a rod that includes a first portion and a second portion, wherein the first portion is connected to the piston and configured to adjust an amount of pressure exerted against the shear thickening fluid. 
     In some examples, the first portion is configured to slide with respect to the second portion with movement of the piston in response to the force applied to the cap. In some examples, the piston includes a shim including one or more slots, and a piston head including one or more slots, wherein the shim is configured to rotate with respect to the piston head to adjust alignment between the one or more slots of the shim and the one or more slots of the piston head. 
     In examples, the second portion is connected to a knob that is located opposite the cap, wherein the knob can be rotated to rotate the second portion connected to the first portion thereby rotating the shim relative to the piston head. 
     In disclosed examples, a device for controlling the motion of a door, includes a body that includes a chamber filled at least in part with a shear thickening fluid, the body being configured to be connected to a first hinge leaf of a door hinge, wherein the body includes a piston and a cam in the chamber, and a pin that is connected to a second hinge leaf of the door hinge and that is connected to the cam, and wherein when the second hinge leaf is rotated, the pin rotates, which causes the cam to rotate and push the piston to exert pressure against the shear thickening fluid. 
     In some examples, the piston includes a piston head. In examples, a shim, wherein both the shim and the piston head include one or more slots. In examples, the one or more slots of the shim have a shape and size approximately equal to the one or more slots of the of the piston head. In examples, the shim is configured to rotate with respect to the piston head thereby adjusting the amount of resistance experienced by the piston. In some examples, rotation of the shim to a first position substantially aligns the one or more slots of the shim with the one or more slots of the of the piston head, and rotation of the rebound shim to a second position substantially misaligns the one or more slots of the shim with the one or more slots of the of the piston head. 
     In some examples, a cam follower arranged in the chamber and connected to the cam on a first end and connected to the piston on a second end, wherein the cam includes a raised portion to move the cam follower axially as the cam rotates. In examples, rotating the first hinge leaf away from the second hinge leaf rotates the cam in a first direction causing the cam follower to push the piston away from the cam. 
     In some examples, rotating the first hinge leaf toward the second hinge leaf rotates the cam in a second direction allowing the cam follower to move the piston toward the cam. In examples, a spring to bias the cam follower toward the cam, thereby forcing the cam follower toward the cam as the first hinge leaf rotates toward the second hinge leaf. 
     In disclosed examples, a device for controlling the motion of a door, includes a body that includes a first chamber filled at least in part with a shear thickening fluid, and a second chamber fluidly isolated from the first chamber, the body being configured to be connected to a first hinge leaf of a door hinge, wherein the body includes a piston and a cam in the chamber, a cam arranged in the second chamber and connected to a second hinge leaf of the door hinge, a cam follower arranged in the second chamber and connected to the cam on a first end and connected to a piston on a second end, wherein the piston is arranged in the first chamber, and wherein, when the second hinge leaf is rotated, the cam rotates, which causes the cam follower to push the piston to exert pressure against the shear thickening fluid. 
     In some examples, the piston includes a shim including one or more slots, and a piston head including one or more slots, wherein the shim is configured to rotate with respect to the piston head to adjust alignment between the one or more slots of the shim and the one or more slots of the piston head. 
     In examples, a cap adjuster that includes a rod extending into the chamber, wherein the piston includes a plug having a slot that is configured to receive the rod. In examples, the plug is configured to secure the shim relative to the piston head. In examples, the rod is configured to mate with the slot of the plug such that rotation of the cap adjuster causes rotation of the plug and the shim, thereby adjusting the amount of alignment between the shim and the piston head. 
     In some examples, the one or more slots of the shim have a shape and size approximately equal to the one or more slots of the of the piston head. 
     In some examples, the cam includes a raised portion to move the cam follower axially as the cam rotates. In examples, rotating the first hinge leaf away from the second hinge leaf rotates the cam in a first direction causing the cam follower to push the piston away from the cam. 
     In some examples, rotating the first hinge leaf toward the second hinge leaf rotates the cam in a second direction causing the cam follower to move the piston toward the cam. In examples, a spring to bias the cam follower toward the cam, thereby forcing the cam follower toward the cam as the first hinge leaf rotates toward the second hinge leaf. 
     In disclosed examples, a device for controlling the motion of a door, including a first hinge leaf that includes a chamber filled at least in part with a shear thickening fluid, the chamber further retaining a bushing and a plunger, wherein the bushing and plunger are connected to a screw, and a second hinge leaf that includes a nut and a portion of the screw, and wherein when the first hinge leaf is rotated, the screw rotates such that the bushing and plunger move vertically such that a piston connected to the plunger exerts pressure against the shear thickening fluid. 
     In some examples, the piston includes a piston head. In examples, a shim, wherein both the shim and the piston head include one or more slots. In examples, the one or more slots of the shim have a shape and size approximately equal to the one or more slots of the of the piston head. 
     In some examples, the shim is configured to rotate with respect to the piston head thereby adjusting the amount of resistance experienced by the piston. In examples, rotation of the shim to a first position substantially aligns the one or more slots of the shim with the one or more slots of the of the piston head, and rotation of the rebound shim to a second position substantially misaligns the one or more slots of the shim with the one or more slots of the of the piston head. 
     In some examples, an extension connected to the shim and when the extension is rotated, the shim is rotated with respect to the piston head. In examples, a knob that is connected to the extension, wherein the knob can be rotated to rotate the extension. 
     In some examples, a dowel pin to extend through the screw, the bushing and the plunger. In examples, the bushing includes a slot oriented with vertical movement of the lead screw, the dowel pin partially extending into the slot. In examples, the slot limits the vertical movement of the dowel pin, the screw, the bushing and the plunger during rotation of the screw. 
     In some examples, the screw, the bushing and the plunger are held in the same rotational position relative to each other during rotation of the screw. 
     In some examples, a cap connected to the nut, the cap including a shaft to receive a portion of the screw during rotation of the screw. 
     In disclosed examples, a device for controlling the motion of a door, including a screw nut configured to receive a screw, a bushing connected to the screw, wherein rotation of the bushing relative to the screw nut causes the screw to move into or out from the screw nut, and a piston connected to the bushing, wherein movement of the screw rotates causes the piston to move vertically such that the piston exerts pressure against a shear thickening fluid. 
     In some examples, the piston including a shim including one or more slots, and a piston head including one or more slots, wherein the shim is configured to rotate with respect to the piston head to adjust alignment between the one or more slots of the shim and the one or more slots of the piston head. 
     In some examples, a spacer plug to secure the shim to the piston. In examples, a knob adjuster that includes an extension configured to mate with the spacer plug, such that rotation of the knob adjuster rotates the shim relative to the piston head, thereby adjusting alignment between the one or more slots of the shim and the one or more slots of the piston head. 
     In some examples, the device is configured to be inserted into a hinge comprising a first hinge leaf and a second hinge leaf. In examples, the first hinge leaf includes a chamber filled at least in part with the shear thickening fluid, the piston arranged within the chamber. 
     In some examples, the second hinge leaf includes the screw nut, wherein when the first hinge leaf is rotated, the screw rotates such that the bushing and piston move vertically such that the piston exerts pressure against the shear thickening fluid. 
     The Linear Motion Control System 
       FIGS. 1-7B  show views of a linear motion control system  10  (e.g., a pin) according to an embodiment of the present technology. The system  10  includes a generally cylindrical body  14  that includes a threaded outer portion  18  and a generally smooth outer portion  22 . The threaded outer portion  18  is configured to be received in a nut  26 . The threaded outer portion  18  and the nut  26  allow the system  10  to be threadably secured to any number of devices with respect to which the system  10  can be used to control motion. The body  14  defines an inner chamber  30 . 
     As shown in  FIG. 2 , the system  10  includes a piston plunger  34  that is inserted and held in place in the inner chamber  30  by a bushing  38 . The system  10  includes a spring  42  that is inserted into a cavity in the bushing  38 . A plunger cap or tip  46  is inserted into the bushing  38  and onto the plunger  34  such that the spring  42  is positioned in a cavity of the plunger cap  46 . The bushing  38  serves as a guide for the plunger  34  and the plunger cap  46 , and as a stop for the spring  42 . The system  10  includes a piston head  50  that is positioned in the chamber  30  and that is connected to the plunger  34 . The system  10  further includes a plug  54  that is connected to the plunger  34 . The system  10  further includes a shim  74  that is mounted to a rod  78  that in turn is mounted to the plug  54 . 
     With reference to  FIGS. 5A and 5B , the shim  74  has one or more slots  82  that generally match one or more slots  86  through piston head  50  in one or both of size and/or shape. Shim  74  includes a generally D-shaped hole  102 , although additional or alternative holes and hole shapes are considered. The rod  78  is connected to a rotatable adjustment knob  90 . 
     With respect to  FIGS. 5A-6 , the rod  78  includes first and second portions  94  and  98 . The first portion  94  is connected to the knob  90 . The first and second portions  94  and  98  can slide with respect to each other in the directions of arrows A and B. The second portion  98  includes a generally D-shaped lip portion  106  that is received in the hole  102  of the shim  74 . The lip portion  106  of the second portion  98  receives a portion of the plug  54  that is connected to the plunger  34 . As shown in  FIGS. 5A and 5B , the plug  54  can includes threads  72  that allows for it to be threadably connected to the plunger  34 . The lip portion  106  of the second portion  98  is rotatable with respect to the plug  54 . The piston head  50  includes a counterbore with a protrusion  110 . The lip portion  106  of the second portion  98  extends into the counterbore and the protrusion  110  limits how far the second portion  98  can rotate in the directions of Arrows C and D. 
     In some examples, the plug, lip portion, shim and piston head can be connected and oriented such that the blocking of further rotation of the lip portion in a first direction by the protrusion can indicate to the user that the slots of the shim and the slots of the piston head are aligned and that the blocking of further rotation of the lip portion in a second, opposite direction by the protrusion can indicate to the user that the slots of the shim and the slots of the piston head are not aligned. In some examples, the system includes an indicator (e.g. a visual, audible, tactile, etc.) that provides information regarding alignment of the slots of the shim and the slots of the piston head. For instance, one or more markers (e.g. lines, letters, numbers, graphics, colors, etc.) may be provided on the knob and/or a portion of the system to indicate an amount of resistance and/or alignment of the slots. 
     Returning to  FIG. 2 , a retaining ring  58  is placed onto an upper groove of the bushing  38  and O-rings  60  and  62  are placed into grooves in the bushing  38  and the piston head  50 . A collar or nose guide  68  is secured to the bushing  38  to enclose the chamber  30  and retain the bushing  38  and plunger cap  46  in place. The collar  68  can be secured to the bushing  38  by a press fit or by any number of other means. 
     The portion of the chamber that does receive the bushing  38  defines a hydraulic chamber  66  that is filled with shear thickening or dilatant fluid  70 . Shear thickening fluid (“STF”, or dilatant material) is a Non-Newtonian fluid that stiffens when acted upon by pressure and/or speed. For example, the greater the speed and/or pressure, the stiffer the fluid becomes. When the speed and/or pressure is light, the fluid is flowable. When the speed and/or pressure is higher, it begins to act more like a solid. 
     In operation, the assembly  10  is threadably inserted into and connected to an object such that the assembly  10  can be used to control and dampen motion of devices that engage the object. For example, the assembly  10  could be used with industrial equipment to dampen the motion of one device that moves relative to and engages with another device. In that regard, the assembly  10  is positioned in the object so the plunger cap or tip  46  can be engaged by a moving device. 
     The amount of resistance to the movement of the device(s) can be adjusted by controlling the size of a slot through which the STF flows. For example, a user can rotate the knob  90  clockwise or counterclockwise to adjust how the slots  82  of the shim  74  align with the slots  86  of the piston head  50 . Specifically, by turning the knob  90 , the first rod portion  94  engages the second rod portion  98  and causes the second rod portion  98  to rotate. As the second rod portion  98  rotates, the shim  74  likewise rotates. The protrusion  110  of the piston head  50  limits how far the lip  106  of the second portion  98 , and thus the shim  74 , can be rotated in either direction. Rotation of the second portion  98  and the shim  74  does not cause the plug  54  or plunger  34  to rotate. Once the shim  74  has been rotated to the desired position, the plunger cap  46  is engaged by the moving device, and the plunger cap  46  is pushed into the body  14  and through the bushing  38  such that the plunger cap  46  pushes against the plunger  34  and spring  42 . That action leads to the piston head  50  and shim  74  moving with respect to the fluid  70  in a direction toward the knob  90 . The fluid  70  reacts to the force and speed of that impact and stiffens or remains flowable depending on the force applied and how the slots  82  and  86  are aligned. The movement of the plunger cap  46  also causes the second rod portion  98  to move toward the knob  90 , such that the second rod portion  98  slides along the first rod portion  94  in the direction of Arrow A, as illustrated in  FIG. 6 . 
     The ability of the fluid  70  to resist the force of the depressed plunger cap  46  (and thus control the speed and/or force of the device contacting the cap  46 ) depends on the alignment of the slots  82  of the shim  74  and the slots  86  of the piston head  50 . For example, if the shim  74  has been rotated to a first setting (e.g., by the user turning the adjustment knob  90 ) such that its slots  82  do not align with the slots  86  in the piston head  50 , the fluid  70  will resist the movement of the piston plunger  34 , and the plunger cap  46  will not depress. This, in turn, will cause an abrupt and hard stop to the device that contacts the plunger cap  46 . 
     If, however, the knob  94  is turned to a second setting to align the slots  82  on the shim  74  with the slots  86  on the piston head  50 , then the fluid  70  flows more easily between the shim  74  and the piston head  50  and does not resist movement of the plunger  34  and cap  46  as much. Thus, in this way, the compression of the fluid  70  is at its lightest setting. Of course, the knob  94  can be rotated to other positions besides the first and second positions to fine tune the setting of fluid  70  compression or resistance that the user desires for a particular application. The rotation in either direction is limited by the protrusion  110  that engages the second rod portion  98 . 
     The reactivity to force of the fluid  70  lets the system  10  control the device engaging the plunger cap  46  due to the stiffening effect of the material make-up (e.g., a polymeric material) of the fluid  70 . The fluid  70  also serves to control, in combination with the selection of the spring rate of spring  42 , the return force from the plunger cap  46  so that it does not return to its fully extended position with such speed or force that it can damage the device that engages it. In that regard, the spring  42  returns the plunger  34  to its fully extended position with the combination of the selected spring rate and the engineered shear thickening fluid  70  controlling the rate of return, and thus not allowing a spring-back effect. 
     With respect to  FIG. 7A , the slots  86  of piston head  50  can be pitched with the wider part of the opening facing the fluid  70  and the narrower part on the backside of the piston head  50  such that the slots  86  are substantially “V” shaped. This structure can help the shear thickening fluid  70  stack up (stiffen) as the piston plunger  34  pushes through the fluid  70 . 
     Additionally, the shear thickening fluid  70 , as engineered, may have nanoparticles of a specific dimension that are mixed in a non-toxic carrier fluid or solvent. Force applied to the shear thickening fluid  70  results in these nanoparticles stacking up, thus stiffening and acting more like a solid than a flowable liquid. Examples of shear thickening fluid are disclosed or described in U.S. Pat. No. 7,825,045 and U.S. Published Application No. 2020/0011110 (U.S. patent application Ser. No. 16/502,470), which are incorporated herein in their entireties by reference. 
     The particles of shear thickening fluid  70  may be, by way of example, oxides, calcium carbonate, synthetically occurring minerals, naturally occurring minerals, polymers, or a mixture thereof. The particles may also be, by way of example, SiO 2 , polystyrene, or polymethylmethacrylate. The solvent may be, by way of example, water, which may contain salts, surfactants, and/or polymers. The solvent may also be, for example, ethylene glycol, polyethylene glycol, ethanol, silicon oils, phenyltrimethicone or a mixture thereof. In some examples, the particles may have an average diameter size that is less than 1 millimeter, and may have an average diameter size of less than 100 microns. By way of example, the shear thickening fluid  70  may be made of silica particles suspended in polyethylene glycol. By further way of example, silica particles may suspended in the polyethylene glycol at a volume fraction of approximately 0.57. The silica particles may have an average particle diameter of approximately 446 nm. The fluid may have a shear thickening transition at a shear rate of approximately 102-103 s-1. 
     Again, a simple rotation of the knob  90  allows the user to control the valve sensitivity based on the feel they want when closing the door. Turning the knob  90  to the first position locks the plunger cap  46  and stops movement of the device that engages the plunger cap  46  because the shim  74  blocks shear thickening fluid  70  from passing to the slots  86  the piston head  50 . Turning the knob to the second position allows the plunger cap  46  to move at a controlled speed because the slots  82  on the shim  74  are generally aligned with the slots  86  on the piston head  50 , allowing the fluid to pass through the piston head  50 . However, the fluid still reacts to speed and pressure. Therefore, the system still controls the movement of the device engaging the plunger cap  46 . 
     The shim  74  may float on the lip portion  106  of the rod  78 , such that the shim  74  is not in a fixed position with respect to the piston head  50 . Thus, the shim  74  can press against the piston head  50  when the shear thickening fluid  70  is being compressed, and pull away from the piston head  50  when the plunger  34  rebounds back to its extended position. Alternatively, the shim  74  may be held in a fixed position with respect to the piston head  50  and/or in contact with the piston head  50 , but still be rotatable with respect to the piston head  50  via turning of the knob  90 . 
     The Pin System 
       FIGS. 8 to 31  illustrate an example pin system (also referred to as a “SlamBlok Pin”) that is configured to replaces a hinge pin in a door hinge and that controls the slamming of a door. 
     As shown in  FIGS. 8-11 , a hinge pin assembly  200  includes one or more of a piston assembly  202  which includes a rebound shim  204  and a piston head  206 . The piston assembly  202  is configured to control movement of the pin assembly  200  by applying force against a STF  230  within a chamber  232  (e.g., within a body or chamber housing  226 , as shown in  FIG. 11 ). A cap  212  includes a cap adjuster  214 , by which an operator may rotate the shim  204  relative to the piston head  206  to change an amount of overlap between shim slots  238  and piston slots  240 . As the amount of overlap between slots  238  and  240  changes, the size of a channel through which the STF  230  may flow changes, thereby modifying the resistance the piston assembly  202  meets when pressing against the STF  230 . 
     The first and second leaves  220 ,  222  may include first and second hinge knuckles  220 A and  222 A, respectively, through which a pin  228  may be inserted. A fastener  218  is configured to secure the pin assembly  200  in place once inserted through the first and second hinge knuckles  220 A and  222 A. The leaves  220  and/or  222  may include one or more fasteners or screw holes  224  to facilitate securing the hinge to a door. 
     A hinge cam  210  is arranged at an edge of a hinge that includes first and second leaves  220  and  222 , with a dowel  216  extending from the hinge cam  210  to force rotation of the hinge cam  210  relative to rotational movement of the leaves. The chamber housing  226  includes one or more protrusions  227  that extend toward the hinge. In some examples, the one or more protrusions  227  contact the hinge leaf  222 , such that the chamber housing  226  moves along with rotation of leaf  222 . The dowel  216  contacts the hinge leaf  220 , such that the hinge cam  210  moves with rotation of leaf  220 . 
     In some examples, the piston assembly  202  rests within the cap  212  when leaves  220  and  222  are in contact (e.g., when a corresponding door is closed). A spring  208  is arranged in chamber  236  and biased against the cam follower  254 , forcing the cam follower  254  towards the hinge cam  210  as a raised portion  252  ( FIG. 13 ) of the hinge cam  210  rotates. Relative rotation increases the distance between leaves  220  and  222  (e.g., upon opening of the door) while the cam follower  254  is forced away from the cap  212 , thereby creating space between the piston assembly  202  and the adjustment cap  214 . 
     As the hinge cam  210  rotates in response to rotation closing the distance between the leaves  220  and  222  (e.g., as the door closes), the hinge cam  210  rotates, which causes the cam follower  254  to move toward the cap  212 , forcing the piston assembly  202  toward the cap  212 . As shim  204  and piston head  206  move against the STF  230 , the resistance to the movement is controlled by the amount of alignment between the slots  238  and  240 . In some examples, STF  230  can flow around edges of the shim  204  and/or through the slots  238 . 
     In some examples, the shim  204  may float on a generally D-shaped lip portion  237  of the plug  242 , such that the shim  204  is not in a fixed position with respect to the piston head  206 . Thus, the shim  204  can press against the piston head  206  when the shear thickening fluid  230  is being compressed, and pull away from the piston head  206  when the assembly  202  rebounds back to its closed position. Alternatively, the shim  204  may be held in a fixed position with respect to the piston head  306  and/or in contact with the piston head  306 , but still be rotatable with respect to the piston head  306  via turning of the cap adjuster  214 . 
     The movement of the cam follower  254  also forces the spring  208  to compress, thereby forcing maintained contact between the cam follower  254  and the hinge cam  210  in preparation for another rotation. 
     With reference to  FIGS. 12 and 13 , the piston head  206  is mounted to a plunger shaft cam  244 . A shoulder bolt  234  is configured to screw into the plunger shaft cam  244 . The piston head  206  is mounted to the plunger shaft cam  244  and a rebound spacer plug  242  is positioned between the shoulder bolt  234  and the piston head  206 . Shim  238  is mounted to the plug  242  and spaced axially from the piston head  206 . A D-shaped rod  211  of the cap adjuster  214  mates with the shoulder bolt  234  such that rotation of the cap adjuster  214  causes rotation of the plug  242  and thus the shim  204 , which allows the user to adjust the amount of alignment between the shim  204  and the piston head  206 . The cam follower  254  is secured to the plunger shaft cam  244  via a fastener  246 . The pin  228  extends through the hinge cam  210  and is secured in place by the fastener  218 . The cap adjuster  214  is configured to rotate about a central axis  215 . 
       FIGS. 14-18  illustrate the chamber housing  226  as configured to contain movable parts of the assembly  200 . For example, the piston assembly  202  is housed within the chamber  232  of the chamber housing  226 , such that the piston assembly  202  moves along the central axis  215  defined by the pin  228  ( FIG. 13 ). 
     As shown in  FIGS. 19-24 , the piston assembly  202  is secured to the plunger shaft cam  244  by shoulder bolt  234 . The plunger shaft cam  244  includes a shoulder bolt D-driver  256  configured to mate with threaded portion  260  of shoulder bolt  234 , which is configured to accept the D-shaped rod  211  ( FIG. 11 ) of the cap  212  as the piston assembly  202  moves toward and/or away from the adjustable cap  214  in response to rotational movement of the hinge cam  210 . At an opposite end of the plunger shaft cam  244  is an end portion  258  manufactured to mate with fastener  246  ( FIG. 11 ). 
     As disclosed herein, a position of slots  238  in the shim  204  can be adjusted relative to slots  240  in the piston head  206 , creating a channel of adjustable size through which STF  230  flows. For example, when slots  238  and  240  are substantially aligned, a maximum amount of STF  230  may flow therethrough as the piston assembly  202  moves towards the cap  212 . As the slots  238  and  240  become more out of alignment, the channel narrows, causing the STF  230  to flow less readily, thereby increasing resistance and slowing movement of the hinge cam  210  and piston assembly  202  toward the cap  212  and, therefore, slowing the rotation of the leaves  218  and  220  toward each other. 
     With respect to  FIG. 24 , the plug  242  includes a generally D-shaped lip portion  237  that is received in the hole  239  of the shim  204 . The lip portion  237  of the plug  242  is received in counterbore  243  of the piston head  206 . As shown in  FIG. 24 , the shoulder bolt  234  includes threads  260  that allows for it to be threadably connected to the shoulder bolt D-driver  256  of plunger shaft cam  244 . The lip portion  237  of the plug  242  is rotatable with respect to the piston head  206 . For example, the lip portion  237  extends into the counterbore  243  and a protrusion  247  extends into the counterbore  243  to limit how far the lip portion  237  (and thereby the shim  204 ) can rotate in the directions of Arrows C and D when the cap adjuster  214  is rotated. 
     In some examples, the plug, lip portion, shim and piston head can be connected and oriented such that the blocking of further rotation of the lip portion in a first direction by the protrusion can indicate to the user that the slots of the shim and the slots of the piston head are aligned and that the blocking of further rotation of the lip portion in a second, opposite direction by the protrusion can indicate to the user that the slots of the shim and the slots of the piston head are not aligned. In some examples, the system includes an indicator (e.g. a visual, audible, tactile, etc.) that provides information regarding alignment of the slots of the shim and the slots of the piston head. For instance, one or more markers (e.g. lines, letters, numbers, graphics, colors, etc.) may be provided on the knob and/or a portion of the system to indicate an amount of resistance and/or alignment of the slots. 
       FIGS. 25-30  illustrate an example hinge cam  210  secured to pin  228 . As shown, the pin  228  extends through the hinge cam  210 , which is secured in place by fastener  218  (e.g., when inserted into the knuckles  220 A and  222 A). One or more dowels  216  are inserted into the hinge cam  210  and extend from a surface of the hinge cam  210  toward the pin  228 . The dowel(s)  216  are configured to engage a hinge leaf (e.g., a dowel  216  is positioned against a leaf) and respond to rotational movement of the leaf. 
     With reference to  FIG. 11 , chamber housing  226  contains the STF  230  in this first or upper chamber  232  and the hinge cam  210  and spring  208  are in the second or lower chamber  236 . The hinge cam  210  turns the rotary motion of the hinge pin  228  (which is caused to rotate by a rotating leaf engaging the dowels  216 ) into linear motion, thus driving the plunger shaft cam  244  toward the cap  212  and into the upper chamber  232  through the STF  230 . Slots  240  in piston head  206  allow STF  230  (such as that described above with respect to the linear motion control device) to flow through them at a rate determined by the adjustment of the rebound shim  204  that can be rotated to leave open, partially cover, or fully cover the slots  238 . When the slots are fully covered, the system is in a locked-out position in which the piston cannot travel and, thus, the door cannot be closed. 
     The pin  228  retains the assembly  200  in the hinge body. In order to install the assembly  200 , the user removes an existing hinge pin in the knuckles  220 A and  220 B of the door hinge. The pin  228  of the assembly  200  can then be inserted into the hinge knuckles  220 A and  220 B with the keyed portion of the bottom of the chamber housing  226  fitting over the leaf  220 ,  222  of one of the hinge plates. The pin tightening screw  218  is then tightened which slightly flares the bottom of the pin  228 , securing it to the bottom portion of the opposite hinge leaf (where chamber housing  226  is keyed and secured). In some examples, the arrangement of the pin  228  is fixed relative to one or both of knuckle  220 B and hinge cam  210 . 
     Since the chamber housing  226  and the pin  228  are secured to separate hinge leaves  220 ,  222 , as the door closes, one hinge leaf rotates relative to the other, which causes the pin  228  which is secured to the hinge cam  210 , to rotate relative to the chamber housing  226 . The hinge cam  210  then rotates, which causes the cam follower  254  to push the assembly of  202  (including plunger shaft cam  244  and shoulder bolt  234  and shim  204 ) though the upper chamber  232  that is filled with STF  230 . Due to the properties of the STF  230 , the assembly  202  is met with resistance as it is pushed into the upper chamber  232 , slowing the advancement of the assembly  202  and thereby slowing rotational movement of the door. 
     The resistance on the shim  204  from the STF  230  may cause the shim  204  to move to or away from the plunger head  206 . For example, as the assembly  202  moves toward cap  212  within the chamber  232 , the shim  204  may be forced toward or against the plunger head  206 . In the case that slots of the shim  204  and the plunger head  206  are out of alignment, the STF  230  may significantly slow movement of the assembly  202 . 
     When the door is opened, the piston assembly  202  reverses itself and the shim  204  lifts up off of piston head  206 , stopping on the shoulder of rebound spacer plug  242 . This allows the slots  240  of piston head  206  to be fully exposed and the flow rate of the STF  230  to be maximal. This reverse movement is partially due to force from the spring  208  pushing against the cam follower  254  to orient itself with the hinge cam  210 , as it returns to a lower (door open) position to prepare the cam follower  254  for door closing. This also ensures the assembly  202  is positioned a maximal distance from the cap  212 . Rebound spacer plug  242  also serves a secondary purpose of retaining shim  204  on shoulder bolt  234  so that it does not separate from the piston assembly  202  upon retraction (e.g., as the door is opened). 
     The cap adjuster  214  performs the dual purpose of capping the top of the fluid chamber  232  and acts as an adjustment knob for the user to control the flow rate of the STF  230  through the slots  238  and  240 . The D-shaped rod  211  in the adjustable cap  214  extends into chamber  232  and into a D-shaped slot  235  in the shoulder bolt  234 . Adjustable cap  214  causes the shoulder bolt  234  (and shim  204 , which is connected to the shoulder bolt  234 ) to rotate with respect to the piston head  206 . The adjustable cap  214  has an O-ring  248  sealing the lower chamber  232  and an internal retaining ring  250  (as shown in  FIG. 12 ). Internal retaining rings  250  are used to snap-fit parts together so they cannot be taken apart by the user. These rings are permanent internal snap rings that fit mating grooves on the chamber housing  226 . 
     The Hinge System 
     Turning to  FIGS. 32 to 72 , a hinge system  300  (also referred to as the “SlamBlok Hinge”) that controls the motion of one or more devices, such as the slamming of a door, is shown. 
     The hinge system  300  is configured to replace one or more hinges of a door. As shown in  FIG. 32 , a complete hinge assembly (with the system  300  incorporated through hinge leaves  316  and  318 ) performs a similar function as the pin assembly  200  described above by controlling the closure speed of a door and/or stopping fast or forceful movements with a combination of STF resistance combined with the mechanicals disclosed herein. The user can replace one or more of their existing door hinges to have the control they desire. 
     The disclosed hinge system  300  can be provided in right hand and left-hand versions and can be a complete assembly for the user to install. In other words, no assembly is required by the user, just installation. For example, a first leaf  318  (e.g., a right hand hinge jamb) is attached to the jamb of the door opening and a second leaf  316  (e.g., a right hand opening hinge door) is attached to the door. The leaves  316  and  318  include holes  320  for receiving fasteners that connect the leaves  316  and  318  to the door or jamb. 
     With reference to  FIGS. 34 and 35 , the hinge system  300  turns the rotary motion of the hinge into linear motion using a lead screw mechanism  308  combined with a mating lead screw nut  350  (e.g., an Igus nut right hand nut) to drive a plunger rod  359  which drives a piston assembly  302  (including a piston head  306  and/or a rebound shim  304 ) though the STF  330  as the door is closed. The mating nut  350  is held stationary within a housing  344  by a key  351  (e.g., a key sized ⅛″). A plunger bushing  361  serves the dual purpose of maintaining the concentric position of the plunger rod  359  and sealing an STF chamber  328  area within a chamber housing  334  (or bushing pin) inserted in first leaf  318 . The seal of the plunger bushing  361  on the plunger rod  359  and the in the STF chamber area  328  of chamber housing  334  is accomplished by O-rings  356 , and plunger bushing  361  is retained in place by a retaining ring  309 . 
     The lead screw mechanism  308  is keyed to the plunger bushing  361  with a dowel pin  354  which keeps plunger bushing  361  and lead screw mechanism  308  in the same rotational position in relation to each other while allowing the lead screw mechanism  308  to travel vertically with the rotation of the hinge. 
     The mating lead screw nut  350  never moves up or down. The lead screw mechanism  308  moves up and down which is one of the reasons for the internal space in the pin hinge shaft  311  of cap  312  allowing lead screw mechanism  308  space to rise as the door is opened. The housing  344  is pressed into knuckle  346  of hinge leaf  316 . The plunger bushing  361 , the lead screw mechanism  308 , and the plunger rod  359  are held in the same rotational position relative to each other with the dowel pin  354 . The dowel pin  354  effectively drives the plunger rod  359  since it is connected to both the lead screw mechanism  308  and the plunger rod  359 . Ring  20  snapably retains the mating lead screw nut  350  into the pin hinge shaft  311  of cap  312 , as shown in  FIG. 34 . 
     A pin  352  connects (or “keys”) the bushing  361  to the hinge leaf  318  such that, as the hinge leaf  318  rotates, the plunger bushing  361  rotates with the hinge leaf  318 . In other words, both bushing  361  and hinge leaf  318  rotate with respect to hinge leaf  316 . The keyway on the two hinge leafs ( 316 ,  318 ) line up so that the subassembly (which includes the plunger bushing  361  and pin  352  extending out of the plunger bushing  361 ) can be inserted as a whole cartridge during assembly, i.e., the bushing  361  and pin  352  can be slid through the top knuckle  346  of hinge leaf  316  into the knuckle  347  of hinge leaf  318  such that the pin  352  partially rests in portion  353 A and  353 B, as shown in  FIG. 35 . 
     In operation, when the hinge leaf  318  is rotated from open to closed, the plunger bushing  361 , which is secured to the hinge leaf  318  by pin  352 , rotates with the hinge leaf  318 . As the plunger bushing  361  rotates, it causes the lead screw mechanism  308 , which is connected to the plunger bushing  361  by the pin  354 , to start rotating downward away from mating lead screw nut  350  and pin hinge shaft  311 . As the lead screw mechanism  308  rotates downward, the pin  354  slides downward in the slot in the plunger bushing  361 . As the position of bushing  361  is fixed relative to knuckle  347  of hinge  318 , the relative rotational movement between hinge leaves  316  and  318  forces linear movement of lead screw mechanism  308 . For example, the rotational movement between hinge leaves  316  and  318  forces the lead screw mechanism  308  to rotate within mating lead screw nut  350 , thereby causing the linear motion of the lead screw mechanism  308  and the connected plunger assembly  302 , as disclosed herein. 
     Because the plunger rod  359  is connected to the lead screw mechanism  308  by the pin  354 , the plunger rod  359  moves downward with the lead screw mechanism  308 , which causes the shim  304  and piston head assembly  302  to push into the STF  330  in the chamber  328  of chamber housing  334 . The STF  330  reacts to the engagement from the shim  304  and piston head assembly  302  as previously described depending on how the slots on the shim  304  are aligned with the slots on the piston head assembly  302 . In this way, the STF  330  controls the rotary motion of the hinge leaf  318  when the hinge leaf  318  is closed. Upon opening the door, hinge leaf  318  is rotated away from hinge leaf  316  and the lead screw mechanism  308  screws back up toward the mating lead screw nut  350  and pin hinge shaft  311 . As the lead screw mechanism  308  screws upward, the plunger rod  359 , which is connected to the lead screw mechanism  308 , moves upward as well. 
     With references to  FIGS. 34-36 , a shoulder bolt  332  is configured for insertion to the rebound spacer plug  340 . The shoulder bolt  332  screws into the plunger rod  359 , thereby securing the piston head  306  to the plunger rod  359 . Shim  304  is arranged at an end of the rebound spacer plug  340  such that rotation of the rebound spacer plug  340  can adjust alignment of the shim  304  relative to the piston head  306 . The rebound spacer plug  340  is long enough to provide sufficient distance between the shim  304  and the piston head  306 , such that the rebound shim  304  is allowed to move up and down relative to the piston head  306  during opening or closing of the door, as shown in the cross-sectional view of  FIGS. 36 and 54 . 
     The hinge system  300  includes a knob  314  on a hinge pin shaft bottom  324  of the hinge assembly  300  that can be used to control the flow rate of the STF  330  (such as that described above with respect to the linear motion control device) through the piston slots  372  ( FIG. 56 ) through the use of a rebound shim  304 . The operation is similar to that described above for the linear motion control device. In particular, the fluid flow is controlled by rotating a knob adjuster  326  which passes through the hinge pin shaft bottom  324 , which is knurled and pressed into the lower portion of hinge leaf  316 . The knob adjuster  326  includes a D- or C-shaped extension  367  that is mated to and allows the sliding of the rebound spacer plug  340  along a D- or C-shaped extension  366  up and down the extension  367  of the knob adjuster  326 , as shown in detail, for example, in  FIGS. 44 and 70 . The D-shaped mating of these two parts allows the rotation of the knob adjuster  326  to turn the rebound shim  304 , thus controlling STF flow while the mating D-shape also allows those two parts to bypass each other as the piston head  306  moves up and down ( FIG. 70 ). The retaining ring  327  retains the knob adjuster  326  into the hinge pin shaft bottom  324  while still allowing it to rotate. Thrust washers  343  act as spacers that allow the two hinge leaves to rotate while mating with each other. 
       FIG. 37  illustrates a view of the plunger bushing  361 , including a slot  362  oriented with the linear motion of the lead screw mechanism  308 . In particular, the pin  354  extends into the slot  362  and limits the linear movement (both towards and away from the cap  312 ). This in turn limits the linear movement of the piston assembly  302  within the chamber  328 . As shown in  FIG. 37 , pin  354  is within slot  362  closer to cap  312 , indicating that opening of the door has moved the screw  308  into the cap  312 .  FIG. 37  shows pin  354  within the slot  362  farthest from cap  312 , indicating that closure of the door has moved the lead screw mechanism  308  away from the cap  312 . 
       FIGS. 38-40  illustrate a perspective view of the closed hinge. In the example of  FIG. 38 , a channel  353 C allows pin  352  to access portion  353 B on bushing  361  by being inserted from a top of the hinge. As shown in  FIG. 39 , the cap  312  includes with an indentation  364  to accept pin  352  to force movement of the spring  308  in response to rotation of the hinge leaves. For example, the pin  352  fixes the orientation of the bushing  361  relative to knuckle  347  of hinge leaf  318  such that rotation of the hinge leaf  318  relative to hinge leaf  316  causes the bushing  361  to rotate. Rotation of the bushing  361  forces rotation of pin  354  and the screw  308  relative to the nut  350 , causing the screw  308  to move up or down relative to the cap  312 . Movement of the screw  308  drives the assembly  302  into or out from the chamber  328 , such that the assembly  302  interacts with STF  330  to slow movement of the hinge. 
       FIG. 41  illustrates a front view of the hinge and hinge assembly, with  FIG. 42  showing a cross-section of the hinge and hinge assembly. 
       FIG. 43  illustrates the assembly  300  in the hinge, with mechanicals revealed. As shown, a pin slot  352 A is arranged at a first end of hinge leaf  316  to accept a pin  355  to fix the orientation of the housing  344  and/or the cap  312  relative to the hinge. Pin slot  352 B is arranged at a second end of leaf  318  to accept a pin to fix the orientation of  324  relative to the hinge. 
       FIG. 44  illustrates a cross-sectional view of the hinge assembly  300  with the mechanicals being partially revealed. 
       FIGS. 45-47  provide cross-sectional views of the hinge assembly  300 , of the bottom, center, and top views, respectively. 
       FIGS. 48-51  provide multiple views of the cap  312  and mating lead screw nut  350  held in place by a ring snap internal bore  384 . As shown, slot  345  of housing  344  is aligned with slot  357  of mating lead screw nut  350  to receive key  351 . As shown in  FIG. 48 , mating lead screw nut  350  includes a threaded shaft  382 , which is configured to accept the lead screw mechanism  308  of  FIG. 32 . 
       FIGS. 52-58  illustrate multiple views of the piston assembly  302  and lead screw mechanism  308 .  FIGS. 55 and 56  show exploded views of the piston assembly  302 , with the slots  372  in the rebound shim  304  in relation to the slots  370  in piston cam shape D  306 . For example, plunger rod  359  includes a shaft  371  to accept the lead screw mechanism  308 , with holes  358  to accept a pin or dowel  354  to secure the lead screw mechanism  308 . A D-shaped endpoint  368  is configured to fit the piston  306 . Rebound spacer plug  340  includes the extension  366  to accept shoulder bolt  332  to secure rebound spacer plug  340  to plunger rod  359 . Shoulder bolt  332  includes a fastening end  374  configured to receive a tool to turn the shoulder bolt  332  to screw threaded portion  342  into endpoint  368 . 
     With respect to  FIG. 56 , the plug  340  includes a generally D-shaped lip portion  337  that is received in the hole  339  of the shim  304 . The lip portion  337  of the plug  340  is received in counterbore  365  of the piston head  306 . As shown in  FIG. 56 , the shoulder bolt  332  can includes threads  342  that allows for it to be threadably connected to the endpoint  368  of plunger rod  359 . The lip portion  337  of the plug  340  is rotatable with respect to the piston head  306 . For example, the lip portion  337  extends into the counterbore  365  and a protrusion  349  of the piston head  306  limits how far the lip portion  337  (and thereby the shim  304 ) can rotate. 
     In some examples, the plug, lip portion, shim and piston head can be connected and oriented such that the blocking of further rotation of the lip portion in a first direction by the protrusion can indicate to the user that the slots of the shim and the slots of the piston head are aligned and that the blocking of further rotation of the lip portion in a second, opposite direction by the protrusion can indicate to the user that the slots of the shim and the slots of the piston head are not aligned. In some examples, the system includes an indicator (e.g. a visual, audible, tactile, etc.) that provides information regarding alignment of the slots of the shim and the slots of the piston head. For instance, one or more markers (e.g. lines, letters, numbers, graphics, colors, etc.) may be provided on the knob and/or a portion of the system to indicate an amount of resistance and/or alignment of the slots. 
     In some examples, the shim  304  may float on the lip portion  337  of the plug  340 , such that the shim  304  is not in a fixed position with respect to the piston head  306 . Thus, the shim  304  can press against the piston head  306  when the shear thickening fluid  330  is being compressed, and pull away from the piston head  306  when the assembly  302  rebounds back to its closed position. Alternatively, the shim  304  may be held in a fixed position with respect to the piston head  306  and/or in contact with the piston head  306 , but still be rotatable with respect to the piston head  306  via turning of the adjustable knob  326 . 
       FIGS. 59-64  illustrate multiple views of the piston assembly  302  and lead screw mechanism  308  and plunger bushing  361 . 
       FIGS. 65-67  illustrate multiple views of the pin hinge shaft bottom  324  attached to the adjustable knob  326  and shaft  322 , which is configured for insertion into chamber housing  334 . 
     Thus, as explained herein, the disclosed technology provides a way to control movement of a device, such as a door. Advantageously, it can protect devices from other devices slamming into them and thus help prevent damage to devices, harm to people near the devices, and/or loud noises created by devices contacting each other. 
     It is to be understood that the disclosed technology is not limited in its application to the details of construction and the arrangement of the components set forth in the description or illustrated in the drawings. The technology is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. 
     While various spatial and directional terms, such as top, bottom, lower, mid, lateral, horizontal, vertical, front and the like may be used to describe embodiments, it is understood that such terms are merely used with respect to the orientations shown in the drawings. The orientations may be inverted, rotated, or otherwise changed, such that an upper portion is a lower portion, and vice versa, horizontal becomes vertical, and the like. 
     Variations and modifications of the foregoing are within the scope of the present technology. It is understood that the technology disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present technology.