Linear actuator for chromatography

Abstract

A rod linear actuator for use with a housing and a piston drive device in situations requiring small, precise movements is provided, the housing being associated with an axially rotatable hollow internally threaded shaft. The actuator includes a body, a lead screw engaging the axially rotatable hollow internally threaded shaft and terminating in a piston, and an anti-rotation device extending from the lead screw and engaging one of the body or an opposing second body.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 393,351, filed July 29, 2022.

[0003] Statement on Federally Funded Research and Development

[0004] not applicable. Technical Field

[0005] This disclosure relates to a rod-type linear actuator for use with a housing and piston drive, for applications requiring small, precise movements. More particularly, this disclosure relates to a rod-type linear actuator for use with a motor driving a hollow threaded shaft and with a piston drive, where repeatable, equal, and precise displacements are required. Background Technology

[0006] High-performance liquid chromatography (HPLC) is generally performed using pumps, jet valves, columns, and detectors that are scaled up to deliver samples and fluids, typically of very small volumes, under pressure. The pumped volume can be extremely small, requiring precise pump control and output. These pumps can be piston-driven, requiring the piston to reciprocate smoothly at a controlled forward or backward rate through a highly controlled displacement. It is known to couple such a piston to a linear actuator to achieve this motion. Linear actuators for this purpose typically include a rotating element, such as a lead screw, and a corresponding nut or anti-rotation device. When a nut is used, the lead screw is fixed in place relative to the motor, thus causing the nut, which is prevented from rotating, to move forward or backward along the threads of the lead screw. When an anti-rotation device is used, the system operates slightly differently, wherein the lead screw engages an axially rotatable hollow internally threaded shaft and the anti-rotation device, which is prevented from rotating with the lead screw and, by being fixed relative to the lead screw, causes the lead screw to move forward or backward relative to the internally threaded shaft.

[0007] The problem is that when the anti-rotation device engages the lead screw near the housing rather than near the piston, the lead screw may oscillate or otherwise change position at its distal end (where the piston-driven pump is located), resulting in friction, wear, and a loss of accuracy in piston movement, as the piston must overcome the associated intermittent engagement.

[0008] Therefore, it is desirable to provide a rod-type linear actuator for use with a housing and piston drive mechanism, the housing being associated with an axially rotatable hollow internally threaded shaft, the rod-type linear actuator including a body, a lead screw engaging the axially rotatable hollow internally threaded shaft and terminating at a piston, and an anti-rotation device extending from the lead screw and engaging one of the body or an opposing second body, the anti-rotation device reducing the possibility of changes in piston position and deviations in piston speed and position. Summary of the Invention

[0009] Therefore, this disclosure satisfies the above-mentioned needs and overcomes one or more defects in the prior art.

[0010] Therefore, a rod actuator is provided that provides displacement and is used in conjunction with a housing and a piston drive, the housing containing a motor that drives an axially rotatable hollow internally threaded shaft positioned within the housing. The rod actuator includes a body, a lead screw, an anti-rotation device, and a piston. The body has a rear face and a relatively positioned front face, adapted to be coupled to the housing at the rear face and to the piston drive at the front face. It has a first passage about a central axis of the body, extending from the rear face toward the front face and terminating at an inner surface, the first passage having a first passage cross-sectional profile and a first passage length not less than the sum of the displacement and the length of the anti-rotation device. It has a second passage along the central axis of the body from the front face to the inner surface, the second passage having a second passage length less than the displacement and a second passage cross-sectional profile narrower than the first passage cross-sectional profile. It also has a guide pin attached to the body at the inner surface, the guide pin extending parallel to the central axis of the body with a guide pin length at least equal to the sum of the displacement and the anti-rotation device length and not greater than the first passage length. A lead screw has a lead screw threaded section terminating at a rear end of the lead screw and a lead screw body terminating at a first end of the lead screw opposite the rear end of the lead screw. The lead screw is adapted to engage an axially rotatable hollow internally threaded shaft, wherein the lead screw threaded section has a lead screw thread length greater than the displacement. An anti-rotation device extends from the lead screw at the lead screw body and has a guide pin channel through which it is aligned with a guide pin. The anti-rotation device extends from a front portion to a rear portion, and the guide pin is sized to pass through the guide pin channel to allow slidable movement of the anti-rotation device along the guide pin. The anti-rotation device is sized to move within a first passage. A piston extends from the lead screw at the first end of the lead screw and is sized to slidably reciprocate through a second passage. It is configured for attachment to a piston drive device, has a piston length greater than the displacement, and is sized to reciprocate within the second passage.

[0011] A rod actuator with displacement is also provided and is intended for use with a housing containing a motor and for use with a piston drive that drives an axially rotatable hollow internally threaded shaft positioned within the housing. The rod actuator includes a body, a second body, a lead screw, an anti-rotation device, and a piston. The body has a rear face and a relatively positioned front face, wherein the body is adapted to be coupled to a housing at the rear face and to a piston drive at the front face. The body has a first passage about a central axis extending from the rear face toward the front face and terminating at an inner face, wherein the first passage has a first passage cross-sectional profile and a first passage length not less than the sum of the displacement and anti-rotation device lengths. The body has a second passage along the central axis from the front face to the inner face, wherein the second passage has a second passage length less than the displacement and a second passage cross-sectional profile narrower than the first passage cross-sectional profile. A second body is sized to securely engage one of the body and the housing and has a guide pin attached to the inner face of the second body, wherein the guide pin is parallel to the central axis and has a guide pin cross-sectional profile, and wherein the guide pin extends toward the inner face by a guide pin length at least equal to the sum of the displacement and anti-rotation device lengths. The lead screw has a lead screw threaded section terminating at a rear end of the lead screw and a lead screw body terminating at a first end of the lead screw opposite to the rear end of the lead screw. The lead screw is adapted to engage an axially rotatable hollow internal threaded shaft and has a lead screw thread length greater than the displacement. An anti-rotation device extends from the lead screw away from the central axis of the body at the lead screw body, has an anti-rotation device length from the front to the rear of the anti-rotation device, and has a guide pin channel therethrough. The guide pin channel is aligned with a guide pin, and the guide pin channel is sized to allow slidable movement of the anti-rotation device along the guide pin. The anti-rotation device has an anti-rotation device cross-sectional profile and is sized to fit within a first passage such that the guide pin channel cross-sectional profile is larger than the guide pin cross-sectional profile. The piston extends from the lead screw at the first end of the lead screw along the central axis of the body and is sized to reciprocate slidably through the second passage and is configured to be attached to the piston drive device, wherein the piston has a piston length and a piston cross-sectional profile, and wherein the piston is sized to fit without interference within the second passage.

[0012] Further aspects, advantages, and embodiments of this disclosure will become apparent to those skilled in the art from the following description of various embodiments and the accompanying drawings. Attached Figure Description

[0013] To obtain and to understand in detail the features, advantages, and purposes described in this disclosure, as well as other features, advantages, and purposes that will become apparent, a more specific description of the disclosure briefly outlined above can be obtained by referring to the embodiments of the disclosure illustrated in the accompanying drawings, which form part of this specification. However, it should be noted that the drawings illustrate only typical preferred embodiments of the disclosure and should therefore not be considered as limiting the scope of the disclosure, as other equally effective embodiments are permissible.

[0014] In the attached diagram:

[0015] Figure 1 This is a diagram of a lever-type linear actuator, in which an anti-rotation device engages a fixed guide pin extending from the body.

[0016] Figure 2 This is a diagram of a lever-type linear actuator, in which an anti-rotation device engages a fixed guide pin extending from an opposing second body.

[0017] Figure 3 This is a diagram of a hollow, internally threaded shaft that can rotate axially and is located at the end of a solid motor shaft.

[0018] Figure 4 This is a diagram of a hollow, internally threaded shaft that is axially rotatable and connected to the gear body. Detailed Implementation

[0019] refer to Figure 1 A diagram is provided of a rod-type linear actuator with a displacement of 199°, wherein an anti-rotation device engages a fixed guide pin extending from the body. The rod-type actuator 100 is intended for use with a housing 102 and a piston drive 103. The housing 102 contains a motor 104 that drives an axially rotatable hollow internally threaded shaft 106, which is positioned within the housing 102. The axially rotatable hollow internally threaded shaft 106 may be disposed within the motor 104, or at the end of a solid motor shaft 302 associated with the motor 104, or at the end 404 of a gear body 402 connected to the motor 104. Figure 3 The illustration shows a hollow, internally threaded shaft 106 that is axially rotatable and located at the end of a solid motor shaft 302 associated with motor 104. Figure 4The illustration shows an axially rotatable hollow internally threaded shaft 106 disposed at an end 404 of a gear body 402 connected to a motor 104. The motor 104 may be a stepper motor or other motor that can be precisely controlled (e.g., by an associated processor or control system, which may be a computer). The piston drive may be a pump or other device coupled to the piston 136, and the piston drive may be sealed against the body 108, so that the precise movement of the piston 136 provides a high degree of control and precision in operation. The lever actuator 100 includes a body 108, a lead screw 134, an anti-rotation device 130, and a piston 136.

[0020] The body 108 is positioned between the housing 102 and the piston drive device 103. The body 108 has a rear surface 110 and a front surface 112, wherein the rear surface 110 and the front surface 112 are positioned opposite each other. To maintain its position, the body 108 is adapted to be coupled to the housing 102 at the rear surface 110 and to the piston drive device 103 at the front surface 112.

[0021] The body 108 provides an inner clearance through which the lead screw 134, anti-rotation device 130, and piston 136 pass during operation. The body 108 has a first passage 114 about a central axis 116, extending from the rear face 110 toward the outer front face 112, terminating at an inner face 164. The first passage 114 may have a first passage cross-sectional profile 118, which may be a cylindrical profile and / or another first passage cross-sectional profile, such as defining a rectangular prism. The body 108 also has a second passage 120 along the central axis 116 from the outer front face 112 to the inner face 164, having a second passage length 194 less than a displacement 199. The second passage 120 has a second passage cross-sectional profile 122. The first passage cross-sectional profile 118 may be complementary to the second passage cross-sectional profile 122, such as both being cylindrical. Because the second passage 120 provides a channel for the piston 136, the second passage 120 is narrower than the first passage 114. When both the first passage 114 and the second passage 120 are cylindrical, the cross-sectional profile 122 of the second passage has a diameter smaller than the diameter of the cross-sectional profile 118 of the first passage. The first passage 114 has a first passage length 193 that is not less than the sum of the displacement 199 and the anti-rotation device length 198.

[0022] The body 108 provides a structure to prevent the anti-rotation device 130 from rotating, as well as a structure and space for advancing and retracting together with the lead screw 134 and the piston 136. The body 108 may be provided with a guide pin 128, which is attached to the body 108 at its inner surface 164 and positioned parallel to the body's central axis 116. Advantageously, the guide pin 128 provides a minimal surface area and therefore minimal friction, while ensuring a tight fit between the guide pin 128 and any mating components.

[0023] Refer again Figure 1 When the anti-rotation device 130, the guide screw 134, and the piston 136 advance and retract within the first passage 114, they advance and retract along or parallel to the body central axis 116, thereby preventing engagements that could alter the movement of the piston 136 and any increased friction. The guide pin 128, having a guide pin length 156, has a guide pin cross-sectional profile 166. The guide pin length 156 is at least equal to the sum of the displacement 199 and the anti-rotation device length 198, and not greater than the first passage length 193, to ensure that the anti-rotation device 130 can travel the displacement 199 along the guide pin 128.

[0024] The movement of piston 136 is achieved by the movement of lead screw 134 as a result of the rotation of axially rotatable hollow internal thread shaft 106, regardless of whether the hollow internal thread shaft 106 is located within motor 104, at the end of solid motor shaft 302 associated with motor 104, or at the end 404 of gear body 402 connected to motor 104. To provide rotation, movement, and displacement of piston 136, lead screw 134 has a lead screw threaded section 160 terminating at a rear end 172 and a lead screw body 162 terminating at a first end 170. The lead screw threaded section 160 has a lead screw thread length 152 greater than the displacement 199 to ensure continuous engagement between lead screw 134 and axially rotatable hollow internal thread shaft 106 at maximum displacement, wherein the rear end 172 is opposite to the first end 170. The lead screw 134 is adapted to engage the axially rotatable hollow internal threaded shaft 106, and, by means of the lead screw thread length 152, maintains engagement with the axially rotatable hollow internal threaded shaft 106 at each end of the displacement 199.

[0025] Linear displacement of the lead screw 134 and therefore the piston 136 is made possible by an anti-rotation device 130, which moves together with the lead screw 134 and maintains the lead screw 134 along the body's central axis 116. (Reference) Figure 1The anti-rotation device 130 extends from the lead screw 134 away from the central axis 116 of the lead screw body 162, and has a guide pin channel 132 therethrough, and an anti-rotation device length 198 from the front portion 196 to the rear portion 195 of the anti-rotation device. The guide pin channel 132 has a profile consistent with the guide pin cross-sectional profile 166, both of which may be cylindrical. The anti-rotation device 130 may be attached to the lead screw 134 or may be formed from the lead screw 134. The guide pin channel 132 provides a stop to the rotation of the anti-rotation device 130 during rotation of the axially rotatable hollow internally threaded shaft 106. The guide pin channel 132 is aligned with the guide pin 128, wherein the guide pin 128 is sized to pass through the guide pin channel 132 by means of a guide pin cross-sectional profile 166, which allows the anti-rotation device 130 to slide along the guide pin 128 by means of a guide pin channel cross-sectional profile 176, which may be cylindrical. The guide pin length 156 is at least equal to the sum of the displacement 199 and the anti-rotation device length 198 to ensure that the anti-rotation device 130 can travel the displacement 199 along the guide pin 128. The guide pin channel cross-sectional profile 176 is complementary to the guide pin cross-sectional profile 166 and is larger than the guide pin cross-sectional profile 166 to avoid interference, allowing the guide pin 128 and the guide pin channel 132 to provide movement guidance without introducing unnecessary clearance. Therefore, the anti-rotation device 130 will move up and down along the guide pin 128 during forward or backward movement relative to the housing 102 together with the guide screw 134 to provide stability. The anti-rotation device 130 may be provided with one of the following at the guide pin channel 132: a low-friction surface, a coating, and a bearing.

[0026] The anti-rotation device 130 may be sized to slidably fit within the first passage 114 to reduce vibration. The anti-rotation device 130, by its shape, reduces any potential deflection of the lead screw 134 from the body central axis 116. The anti-rotation device 130 may be cylindrical. The anti-rotation device 130 has an anti-rotation device cross-sectional profile 148 that differs from the first passage cross-sectional profile 118, such that the anti-rotation device 130 is sized to fit within the first passage 114. The first passage 114 has a first passage cross-sectional profile 118, and the anti-rotation device 130 has an anti-rotation device cross-sectional profile 148, such that the first passage cross-sectional profile 118 is complementary to and larger than the anti-rotation device cross-sectional profile 148. Therefore, the anti-rotation device cross-sectional profile 148 is sufficiently smaller than the first passage cross-sectional profile 118 to avoid interference, but is sized to fit the first passage 114 to ensure that the anti-rotation device 130 can move forward and backward within the first passage 114 without introducing unnecessary clearance, and thus provides guidance for movement.

[0027] Therefore, the guide pin channel 132 surrounds the guide pin 128 without interference by means of the guide pin channel cross-sectional profile 176, while the anti-rotation device 130 moves without interference within the first passage 114.

[0028] When needed, a second guide pin 128b, preferably opposite the guide pin 128 about the body's central axis 116, can be used to increase stability and reduce deflection or swaying. In use, the second guide pin 128b is attached to the second body 248 at an inner surface 164 of the body, parallel to the body's central axis 116. The second guide pin 128b may have a guide pin cross-sectional profile 166 and extend a guide pin length 156. When the second guide pin 128b is used, the anti-rotation device 130 is provided with a second guide pin channel 132b therethrough, wherein the second guide pin channel 132b is aligned with the second guide pin 128b. The second guide pin 128b is designed by means of the guide pin cross-sectional profile 166 to pass through the second guide pin channel 132b and allow the anti-rotation device 130 to slide slidably along the second guide pin 128b without interference. The second guide pin 128b may have a second guide pin cross-sectional profile 166b, wherein the second guide pin channel 132b has a second guide pin channel cross-sectional profile 176b, such that the second guide pin channel cross-sectional profile 176b is complementary to the second guide pin cross-sectional profile 166b and is larger than the second guide pin cross-sectional profile 166b.

[0029] With the lead screw 134 held along the body central axis 116, the piston 136 can thereby drive the piston drive 103 with minimal misalignment and therefore friction, as well as deviation in the rate of forward or backward movement. The piston 136 extends from the lead screw 134 along the body central axis 116 at a first end 170 of the lead screw and is dimensioned to slidably reciprocate through the second passage 120 and configured for attachment to the piston drive 103. The piston 136 may be integrally formed with or attached to the lead screw 134. The piston 136 has a piston length 174 greater than the displacement 199 to ensure that the piston 136 is always at least partially held within the second passage 120, and thus ensures that the piston 136 cannot be completely withdrawn from the second passage 120. To ensure the necessary forward and backward displacement of piston 136, piston 136 has a piston cross-sectional profile 144 different from the second passage cross-sectional profile 122. This allows piston 136 to be sized for interference-free reciprocating motion within the second passage 120, ensuring forward and backward movement without introducing unnecessary clearance and providing guidance for movement. The second passage 120 has the second passage cross-sectional profile 122, and piston 136 has the piston cross-sectional profile 144, such that the second passage cross-sectional profile 122 is complementary to and larger than the piston cross-sectional profile 144. Since piston cross-sectional profile 144 can be cylindrical, and since the second passage cross-sectional profile 122 can be cylindrical, piston cross-sectional profile 144 has a diameter sufficiently smaller than the diameter of the second passage 120 to avoid interference.

[0030] refer to Figure 2 The illustration provides a rod-type linear actuator 200, wherein an anti-rotation device 130 engages an opposing second body 248. Instead of a body 208 having one or more guide pins 128, one or more guide pins 228 may be provided on the second body 248.

[0031] Body 208 provides a connection between housing 102 and piston drive 103. Body 208 has a rear body surface 110 and a front body surface 112, wherein the rear body surface 110 and the front body surface 112 are positioned opposite each other. To maintain position, body 108 is adapted to be coupled to housing 102 at the rear body surface 110 and to piston drive 103 at the front body surface 112. Body 208 provides an inner clearance through which the lead screw 134, anti-rotation device 130, and piston 136 pass during operation. Body 208 has a first passage 114 about a central axis 116 from the rear body surface 110 toward the front body surface 112, the first passage 114 having a first passage cross-sectional profile 118 and terminating at an inner body surface 164. The body 208 also has a second passage 120 along the body central axis 116 from the outer front surface 112 to the inner surface 164 of the body. The second passage 120 has a second passage cross-sectional profile 122 and a second passage length 194 less than the displacement 199. Because the second passage 120 provides a channel for the piston 136, the second passage cross-sectional profile 122 is narrower than the first passage cross-sectional profile 118.

[0032] The second body 248 is sized to securely engage one or both of the body 208 and the housing 102. The second body 248 may be cylindrical and contained within the first passage 114. The second body 248 may include a profile that mates with the body 208 and prevents rotation of the second body 248 relative to the body 208. The second body 248 may have a second body keyway 271 on its outer surface 272 adapted to receive a key 280, while the body 208 may have a body keyway 270 on its inner surface 273 of the first passage adapted to receive a key 280, wherein the body 208 and the second body 248 are held relative to each other by the key 280.

[0033] The second body 248 has a guide pin 228 attached to the inner surface 264 of the second body 248. The guide pin 228 is parallel to the central axis 116 of the body and has a guide pin cross-sectional profile 266. Therefore, the guide pin 228 extends a guide pin length 156 toward the inner surface 164 of the body. The guide pin length 156 is at least equal to the sum of the displacement 199 and the anti-rotation device length 198. The guide pin 228 has a guide pin cross-sectional profile 266 and extends a guide pin length 156. This is coupled to a modified anti-rotation device 130 having a guide pin channel 132 therethrough. The guide pin channel 132 is aligned with the guide pin 228, and the second guide pin channel 132 is sized to fit the guide pin channel 132 by means of the guide pin cross-sectional profile 266 and the guide pin channel cross-sectional profile 176 to allow the anti-rotation device 130 to slide slidably along the guide pin 228.

[0034] When needed, a second guide pin 228b can be used to increase stability and reduce any deflection or sway. This second guide pin 228b can be opposite the guide pin 228 about the body's central axis 116. When needed, the second guide pin 228b is attached to the second body 248 at an inner surface 264 of the second body, parallel to the body's central axis 116. The second guide pin 228b has a guide pin cross-sectional profile 266 and extends the guide pin length 156. This is coupled to a modified anti-rotation device 130 having a second guide pin channel 132b therethrough. The second guide pin channel 132b is aligned with the second guide pin 228b, and the second guide pin channel 132b is sized to fit the second guide pin channel 228b by means of the guide pin cross-sectional profile 266 and the guide pin channel cross-sectional profile 176 to allow the anti-rotation device 130 to slide slidably along the second guide pin 228b.

[0035] Similarly, the provided variation in which the body 108 has one or more guide pins 128 can be applied to cases where one or more guide pins 228 are disposed on the second body 248, in particular where an axially rotatable hollow internal threaded shaft 106 is disposed within the motor 104, at the end of a solid motor shaft 302 associated with the motor 104, and at the end 404 of a gear body 402 connected to the motor 104, and wherein an anti-rotation device 130 is attached to a lead screw 134, wherein the anti-rotation device 130 is integrally formed with the lead screw 134, and wherein the guide pin channel 132 is sized to fit without interference around the guide pin 128 by means of the guide pin channel cross-sectional profile 176 and the guide pin cross-sectional profile 166, while the anti-rotation device 130 is sized to fit without interference within the first passage 114.

[0036] Therefore, the bodies 108, 208, lead screw 134, anti-rotation device 130 and any second body 248 ensure that the piston 136 moves linearly along the central axis 116 of the body and avoid deviations that may affect the rate of advance of the piston 136.

[0037] The terms and expressions used in the foregoing specification are used herein as descriptive rather than limiting terms, and the use of such terms and expressions is not intended to exclude equivalents of the features shown and described or portions thereof.

Claims

1. A rod actuator (100) having displacement (199) for use with a housing (102) and a piston drive (103), The housing (102) includes a motor (104). The motor (104) drives an axially rotatable hollow internal threaded shaft (106), which is positioned within the housing (102). include: Ontology(108), The body (108) has a rear surface (110) and a front surface (112). The rear surface (110) of the main body is opposite to the front surface (112) of the main body. The body (108) is adapted to be attached to the housing (102) at the rear surface (110) of the body. The body (108) is adapted to be connected to the piston drive device (103) at the outer front surface (112) of the body. The body (108) has a first passage (114) that extends from the rear surface (110) of the body toward the outer front surface (112) of the body around the central axis (116) of the body and terminates at the inner surface (164) of the body. The first passage (114) has a first passage cross-sectional profile (118). The first passage (114) has a first passage length (193) that is not less than the sum of the displacement (199) and the anti-rotation device length (198). and The body (108) has a second passage (120) along the central axis (116) of the body from the outer front surface (112) of the body to the inner surface (164) of the body. The second passage (120) has a second passage length (194) smaller than the displacement (199). The second passage (120) has a second passage cross-sectional profile (122). The second passage cross-sectional profile (122) is narrower than the first passage cross-sectional profile (118). The body (108) has a guide pin (128), The guide pin (128) is attached to the body (108) at the inner surface (164) of the body. The guide pin (128) is parallel to the central axis (116) of the body. The guide pin (128) extends the guide pin length (156), The length of the guide pin (156) is at least equal to the sum of the displacement (199) and the length of the anti-rotation device (198) and is not greater than the length of the first passage (193); The lead screw (134) has a lead screw threaded section (160) terminating at the rear end (172) of the lead screw and a lead screw body (162) terminating at the first end (170) of the lead screw. The rear end (172) of the guide screw is opposite to the first end (170) of the guide screw. The lead screw (134) is adapted to engage the axially rotatable hollow internal threaded shaft (106). The threaded section (160) of the lead screw has a lead screw thread length (152) greater than the displacement (199). An anti-rotation device (130) extends from the lead screw (134) away from the central axis (116) of the main body (162). The length of the anti-rotation device (198) from the front (196) to the rear (195) of the anti-rotation device. The anti-rotation device (130) has a guide pin channel (132) therethrough. The guide pin channel (132) is aligned with the guide pin (128). The guide pin (128) is sized to pass through the guide pin channel (132) to allow the anti-rotation device (130) to slide along the guide pin (128). The anti-rotation device (130) is sized to move within the first passage (114); and Piston (136), The piston (136) extends from the lead screw (134) at the first end (170) of the lead screw along the central axis (116) of the body and is configured for attachment to the piston drive device (103). The piston (136) has a piston length (174) greater than the displacement (199); The piston (136) is sized to reciprocate slidably within the second passage (120). The anti-rotation device (130) has an anti-rotation device cross-sectional profile (148). The first passage cross-sectional profile (118) is complementary to the anti-rotation device cross-sectional profile (148) and is larger than the anti-rotation device cross-sectional profile (148). The first passage cross-sectional profile (118) is complementary to the second passage cross-sectional profile (122). The guide pin (128) has a guide pin cross-sectional profile (166). The guide pin channel (132b) has a guide pin channel cross-sectional profile (176). The guide pin channel profile (176) is complementary to the guide pin profile (166) and is larger than the guide pin profile (166).

2. The lever actuator (100) according to claim 1 further comprises: The body (108) has a second guide pin (128b), The second guide pin (128b) is attached to the body (108) at the inner surface (164) of the body. The second guide pin (128b) is parallel to the central axis (116) of the body. The second guide pin (128b) extends the length of the guide pin (156), and The anti-rotation device (130) has a second guide pin channel (132b) therethrough. The second guide pin channel (132b) is aligned with the second guide pin (128b). The second guide pin (128b) is sized to pass through the second guide pin channel (132b) to allow the anti-rotation device (130) to slide along the second guide pin (128b).

3. The lever actuator (100) according to claim 2, wherein, The axially rotatable hollow internal threaded shaft (106) is disposed in one of the following locations: inside the motor (104), at the end of the solid motor shaft (302) associated with the motor (104), and at the end (404) of the gear body (402) connected to the motor (104).

4. The lever actuator (100) according to claim 3, wherein The anti-rotation device (130) is attached to the lead screw (134).

5. The lever actuator (100) according to claim 3, wherein The anti-rotation device (130) is integrally formed with the guide screw (134).

6. The lever actuator (100) according to claim 3, wherein The second guide pin (128b) has a second guide pin cross-sectional profile (166b). The second guide pin channel (132b) has a second guide pin channel cross-sectional profile (176b). in, The second guide pin channel cross-sectional profile (176b) is complementary to the second guide pin cross-sectional profile (166b) and is larger than the second guide pin cross-sectional profile (166b). The piston (136) has a piston cross-sectional profile (144). The second passage cross-sectional profile (122) is complementary to the piston cross-sectional profile (144) and is larger than the piston cross-sectional profile (144).

7. The lever actuator (100) according to claim 1, wherein... The anti-rotation device (130) is cylindrical.

8. A rod actuator (200) having displacement (199) for use with a housing (102) and a piston drive (103), The housing (102) includes a motor (104). The motor (104) drives an axially rotatable hollow internal threaded shaft (106), which is positioned within the housing (102). include: Ontology(208), The body (208) has a rear surface (110) and a front surface (112). The rear surface (110) of the main body is opposite to the front surface (112) of the main body. The body (208) is adapted to be attached to the housing (102) at the rear surface (110) of the body. The body (208) is adapted to be connected to the piston drive device (103) at the outer front surface (112) of the body. The body (208) has a first passage (114) that extends from the rear surface (110) of the body toward the outer front surface (112) of the body around the central axis (116) of the body and terminates at the inner surface (164) of the body. The first passage (114) has a first passage cross-sectional profile (118). The first passage (114) has a first passage length (193) that is not less than the sum of the displacement (199) and the anti-rotation device length (198). and The body (208) has a second passage (120) along the central axis (116) of the body from the outer front surface (112) of the body to the inner surface (164) of the body. The second passage (120) has a second passage length (194) smaller than the displacement (199). The second passage (120) has a second passage cross-sectional profile (122). The second passage cross-sectional profile (122) is narrower than the first passage cross-sectional profile (118). Second body (248), The second body (248) is sized to securely engage one of the body (208) and the housing (102). The second body (248) has a guide pin (228), The guide pin (228) is attached to the second body (248) at the inner surface (264) of the second body. The guide pin (228) is parallel to the central axis (116) of the body. The guide pin (228) has a guide pin cross-sectional profile (266). The guide pin (228) extends 156 units towards the inner surface (164) of the body. The length of the guide pin (156) is at least equal to the sum of the displacement (199) and the length of the anti-rotation device (198); The lead screw (134) has a lead screw threaded section (160) terminating at the rear end (172) of the lead screw and a lead screw body (162) terminating at the first end (170) of the lead screw. The rear end (172) of the guide screw is opposite to the first end (170) of the guide screw. The lead screw (134) is adapted to engage the axially rotatable hollow internal threaded shaft (106). The threaded section (160) of the lead screw has a lead screw thread length (152) greater than the displacement (199). An anti-rotation device (130) extends from the lead screw (134) away from the central axis (116) of the main body (162). The length of the anti-rotation device (198) from the front (196) to the rear (195) of the anti-rotation device. The anti-rotation device (130) has a guide pin channel (132) therethrough. The guide pin channel (132) is aligned with the guide pin (128). The guide pin channel (132) is sized to a guide pin channel cross-sectional profile (176) to allow the anti-rotation device (130) to slide along the guide pin (128). The anti-rotation device (130) has an anti-rotation device cross-sectional profile (148). The anti-rotation device (130) is sized to fit within the first passage (114). The guide pin channel cross-sectional profile (176) is larger than the guide pin cross-sectional profile (166). Piston (136), The piston (136) extends from the lead screw (134) along the central axis (116) of the body at the first end (170) of the lead screw, and is sized to reciprocate slidably through the second passage (120) and configured for attachment to the piston drive (103). The piston (136) has a piston length (174); The piston (136) has a piston cross-sectional profile (144). The piston (136) is sized to fit into the second passage (120) without interference.

9. The lever actuator (200) according to claim 8, further comprising: The second body (248) has a second guide pin (228b) that is opposite to the guide pin (228) about the central axis (116) of the body. The second guide pin (228b) is attached to the second body (248) at the inner surface (264) of the second body. The second guide pin (228b) is parallel to the central axis (116) of the body. The second guide pin (228b) has the guide pin cross-sectional profile (266). The second guide pin (228b) extends the guide pin length (156) toward the inner surface (164) of the body. The anti-rotation device (130) has a second guide pin channel (132b) therethrough. The second guide pin channel (132b) is aligned with the second guide pin (128b). The second guide pin channel (132b) is sized to fit the second guide pin (228b) to allow the anti-rotation device (130) to slide along the second guide pin (128).

10. The lever actuator (200) according to claim 9, further comprising: The second body (248) has a second body keyway (271) on the outside of the second body (272), the second body keyway being sized to fit the key (280), and The body (208) has a body keyway (270) on the inner surface (273) of the first passage, the body keyway (270) being sized to fit the key (280); and The key (280).

11. The lever actuator (100) according to claim 1, further comprising: The anti-rotation device (130) is provided with one of a low-friction surface, a coating, and a bearing at the guide pin channel (132).

12. The lever actuator (200) according to claim 8, wherein... The anti-rotation device (130) is cylindrical.

13. The lever actuator (100) according to claim 1, wherein... The second guide pin (128b) is positioned opposite the guide pin (128) about the central axis (116) of the body.

Images