Exercise device for preventing senile dementia
The exercise device addresses the limitations of existing devices by enabling simultaneous hand and arm exercises, stimulating acupuncture points, and increasing oxygen intake, thus enhancing its effectiveness in preventing Alzheimer's disease through comprehensive exercise and circulation promotion.
Patent Information
- Application Number
- CN202420688604.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-06
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2034-04-06
AI Technical Summary
Existing exercise devices for preventing Alzheimer's disease do not effectively exercise the hands and cannot stimulate acupuncture points, reducing their effectiveness in preventing the disease.
An exercise device that simultaneously exercises hands and arms, incorporates a hand exercise mechanism with rotating gripping pieces to stimulate acupuncture points, and includes a running mechanism to increase oxygen intake, along with a rotation resistance mechanism using torsion springs to provide resistance during arm exercises.
The device enables simultaneous hand and arm exercises, stimulates acupuncture points to promote blood circulation, increases oxygen intake, and enhances the device's service life by using independent torsion springs, thereby improving its effectiveness in preventing Alzheimer's disease.
Smart Images
Figure CN222286323U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of exercise devices, in particular to an exercise device for preventing senile dementia. Background Art
[0002] Alzheimer's disease is a common group of chronic progressive mental deterioration diseases in the elderly, characterized by decline in memory, calculation, judgment, attention, abstract thinking ability, language function, emotional and behavioral disorders. Alzheimer's disease is preventable. Adequate sleep, a reasonable diet, physical exercise, a good mood, mental activities and interactions with relatives and friends can all help prevent the occurrence of Alzheimer's disease.
[0003] In the Chinese patent publication number CN220237695U, a preventive exercise device for Alzheimer's disease is proposed. By setting an arm strength exercise mechanism and a grip strength exercise mechanism to exercise the user's hands and arms, the patient's finger flexibility and arm strength can be trained, thereby improving the comprehensiveness of the patient's exercise.
[0004] However, the device cannot exercise the hands when exercising the arms, and the hand exercise mechanism can only make the hands perform fisting and stretching movements, and cannot stimulate the acupuncture points on the hands of the user, thereby reducing the use effect of the device. Utility Model Content
[0005] The utility model provides an anti-alzheimer's disease exercise device, which has the advantages of being able to exercise hands and arms at the same time and having a massage effect on the hands, so as to solve the problems raised in the above background technology.
[0006] In order to achieve the purpose of being able to exercise hands and arms at the same time and having a massage effect on hands, the utility model provides the following technical solutions: an anti-Alzheimer's disease exercise device, including a base frame, and also includes: the base frame includes parallel ends on both sides and connecting ends connected between the parallel ends, the upper surfaces of the parallel ends on both sides of the base frame are fixed with support columns, and the upper ends of the support columns are provided with support rods; the support rods include straight rods and curved rods, one end of the curved rods is connected to the support columns, a connecting rod is fixed between the curved rods and the straight rods, and the outer circumferential rotation of the connecting rods is provided with a hand exercise mechanism; a rotation resistance mechanism, the rotation resistance mechanism is arranged in the support column, and the rotation resistance mechanism can apply circumferential resistance to the curved rod; a running mechanism, the running mechanism is arranged between the parallel ends of the base frame, and the running mechanism can allow the elderly to perform running exercises.
[0007] As a preferred technical solution of the utility model, a threaded sleeve is sleeved on the outer circumference of one end of the straight rod opposite to the supporting rod, and a connecting thread is fixedly provided on the outer circumferential surface of the straight rod corresponding to the threaded sleeve. The threaded sleeve can be rotated along the connecting thread and extended to another straight rod, and the connecting thread can prevent the threaded sleeve from detaching from the straight rod.
[0008] As a preferred technical solution of the utility model, the hand exercise mechanism includes a first rotating plate and a second rotating plate, the middle parts of the first rotating plate and the second rotating plate are rotatably connected to the connecting rod, and gripping pieces are rotatably provided on both sides between the first rotating plate and the second rotating plate, and the gripping pieces can rotate around the connecting rod.
[0009] As a preferred technical solution of the utility model, a protrusion is fixedly provided on the outer surface of the gripping piece, and the protrusion can stimulate the hand.
[0010] As a preferred technical solution of the utility model, a cavity is provided at the upper end of the support column, the lower end of the bent rod is located in the cavity, and the bottom end of the bent rod is rotatably connected to the support column; the rotation resistance mechanism includes a first torsion spring and a second torsion spring arranged in the cavity, and the first torsion spring and the second torsion spring have the same rotation direction, the first torsion spring and the second torsion spring are sleeved on the outer circumferential surface of the bent rod, the upper end of the first torsion spring is fixedly connected to a first slider, the lower end of the first torsion spring is fixed in the support column, the lower end of the second torsion spring is fixedly connected to a second slider, and the upper end of the second torsion spring is fixed in the support column; the cavity is The positions of the first slider and the second slider are respectively provided with a first outer semicircular slide groove and a second outer semicircular slide groove, and the first slider and the second slider can slide and rotate in the first outer semicircular slide groove and the second outer semicircular slide groove respectively; the positions of the support rod corresponding to the first slider and the second slider are respectively provided with a first inner semicircular slide groove and a second inner semicircular slide groove, and the first slider and the second slider can slide and rotate in the first inner semicircular slide groove and the second inner semicircular slide groove respectively; the first outer semicircular slide groove and the first inner semicircular slide groove are respectively symmetrical with the second outer semicircular slide groove and the second inner semicircular slide groove about the axis center of the support rod.
[0011] As a preferred technical solution of the utility model, the running mechanism includes an active roller rotatably arranged between the parallel ends of the base frame, a driven roller rotatably arranged at one end between the parallel ends of the base frame away from the active roller, a running belt is sleeved on the outer circumferential surfaces of the active roller and the driven roller, a support plate is arranged between the upper and lower surfaces of the running belt, the upper surface of the support plate contacts with the upper surface of the running belt, fixing parts are fixedly arranged on both side surfaces of the support plate, mounting holes are opened on the sides of the parallel ends of the base frame close to the fixing parts, and the fixing parts can be installed in the mounting holes; a transmission wheel is fixedly installed on one side of the active roller, a motor is fixedly installed on the parallel ends of the base frame, and a transmission belt is connected between the output end of the motor and the transmission wheel.
[0012] As a preferred technical solution of the utility model, a placement plate is fixedly provided on the top end of the support column, and the supporting rod passes through the placement plate.
[0013] As a preferred technical solution of the utility model, a handle is fixedly provided on a side of the upper end of the support column away from the placement plate.
[0014] As a preferred technical solution of the utility model, a protective shell is fixedly installed on the upper surface of the base frame, and the protective shell can prevent debris from falling into the running mechanism.
[0015] Compared with the prior art, the utility model provides an anti-alzheimer's exercise device, which has the following beneficial effects:
[0016] 1. The anti-Alzheimer's disease exercise device, by arranging a hand exercise mechanism and a rotation resistance structure on a support rod, can realize hand exercise and arm exercise through the support rod, can exercise the arm and hand at the same time, and is more convenient to use.
[0017] 2. The anti-alzheimer's exercise device, by providing a gripping piece with a protrusion, can stimulate the acupuncture points of the hand while performing stretching and fisting exercises, thereby stimulating the cerebral cortical nerves and promoting blood circulation in the hand.
[0018] 3. The anti-Alzheimer's disease exercise device increases the service life of the torsion spring and reduces the failure rate of the device by providing a first torsion spring and a second torsion spring that work independently and making the torsion spring only tightened during operation.
[0019] 4. The anti-Alzheimer's disease exercise device can increase the oxygen intake of the user by providing a running mechanism and increasing the exercise methods, which helps stimulate brain cells and improve the use effect of the device. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a schematic diagram of the structure of the utility model;
[0021] Figure 2 This is a structural diagram of the rotation resistance mechanism of the utility model;
[0022] Figure 3 This is the first slider matching diagram of the utility model;
[0023] Figure 4 This is the matching diagram of the second slider of the utility model;
[0024] Figure 5 This is an exploded view of the hand exercise mechanism of the utility model;
[0025] Figure 6 This is a diagram showing the matching of the threaded sleeve and the support rod of the utility model;
[0026] Figure 7 This is a structural diagram of the running mechanism of the utility model.
[0027] In the figure: 1. base frame; 2. protective shell; 3. support column; 31. first outer semicircular slide groove; 32. second outer semicircular slide groove; 4. placement plate; 5. grip; 6. support rod; 61. connecting thread; 62. connecting rod; 63. first inner semicircular slide groove; 64. second inner semicircular slide groove; 7. hand exercise mechanism; 71. first rotating plate; 72. second rotating plate; 73. gripping piece; 731. protrusion; 8. running belt; 81. active roller; 82. driven roller; 9. support plate; 91. fixing piece; 10. transmission wheel; 11. transmission belt; 12. motor; 13. threaded sleeve; 14. cavity; 15. first torsion spring; 16. second torsion spring; 17. first slider; 18. second slider. DETAILED DESCRIPTION
[0028] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0029] See also Figure 1-Figure 2 The utility model discloses an anti-alzheimer's exercise device, including a base frame 1 that supports the device as a whole. The base frame 1 is a U-shaped structure, which includes parallel ends on both sides and connecting ends connected between the parallel ends. Support columns 3 are fixedly arranged on the upper surfaces of the parallel ends on both sides of the base frame 1, and a supporting rod 6 that supports the user is arranged at the upper end of the supporting column 3; the supporting rod 6 is bent, including a horizontally arranged straight rod and a vertically arranged bent rod, one end of the bent rod is connected to the support column 3, a connecting rod 62 is fixedly connected between the bent rod and the straight rod, and a hand exercise mechanism 7 is arranged on the outer circumference of the connecting rod 62 for rotating.
[0030] In addition, a rotation resistance mechanism is also provided in the support column 3. When the support rod 6 rotates around the curved pipe, the rotation resistance mechanism can apply circumferential resistance to the curved rod.
[0031] Furthermore, a running mechanism is provided between the parallel ends of the base frame 1, and the running mechanism enables the elderly to perform running exercises.
[0032] In this embodiment, when the user needs to exercise the hands, the hand exercise mechanism 7 on the support rod 6 can be used to move the hands, thereby promoting blood circulation in the hands; when the arms need to be exercised, the support rod 6 can be pushed or pulled, and the resistance mechanism can be rotated to apply a reverse resistance to the bending rod, thereby exercising the arms; the running mechanism can also be used to perform running or walking exercises, and the support rod 6 can be held during exercise to avoid falling.
[0033] Combination Figure 1 , Figure 6 In order to prevent the two supporting rods 6 from rotating when they play a supporting role, a threaded sleeve 13 is sleeved on the outer circumference of one straight rod at the opposite end of the supporting rod 6, and a connecting thread 61 is fixedly provided on the outer circumferential surface of the straight rod corresponding to the threaded sleeve 13. The threaded sleeve 13 can be rotated along the connecting thread 61 and extended to the other straight rod, so that the two straight rods are sleeved in the threaded sleeve 13, and only one end of the thread inside the threaded sleeve 13 extends to the circular surface of the threaded sleeve 13, thereby preventing the threaded sleeve 13 from detaching from the straight rod.
[0034] Combination Figure 1 , Figure 5 The hand exercise mechanism 7 includes a first rotating plate 71 and a second rotating plate 72. The sides of the first rotating plate 71 and the second rotating plate 72 can be set to an arc shape to avoid hitting the user's hands. The middle parts of the first rotating plate 71 and the second rotating plate 72 are rotatably connected to the connecting rod 62. Both sides between the first rotating plate 71 and the second rotating plate 72 are rotatably provided with gripping pieces 73. The gripping pieces 73 are cylindrical in shape for easy grasping, and the gripping pieces 73 can rotate around the connecting rod 62.
[0035] And, combined with Figure 5 The outer surface of the grip 73 is fixed with protrusions 731, which may be spherical particles. The protrusions 731 can stimulate the hand, thereby stimulating the cerebral cortex and promoting blood circulation in the hand.
[0036] In this embodiment, the user grasps the two gripping members 73 to stretch and clench a fist, so that the gripping members 73 rotate around the connecting rod 62 under the support of the first rotating plate 71 and the second rotating plate 72, and can massage the acupuncture points of the hand through the protrusions 731.
[0037] Combination Figure 2 In order to install the supporting rod 6 in the supporting column 3, a cavity 14 is opened at the upper end of the supporting column 3, the lower end of the bent rod is located in the cavity 14, and the bottom end of the bent rod is rotatably connected to the supporting column 3.
[0038] In addition, the rotation resistance mechanism includes a first torsion spring 15 and a second torsion spring 16 disposed in the cavity 14, and the first torsion spring 15 and the second torsion spring 16 are sleeved on the outer circumferential surface of the bent rod, the upper end of the first torsion spring 15 is fixedly connected to a first slider 17, the lower end of the first torsion spring 15 is fixed in the support column 3, the lower end of the second torsion spring 16 is fixedly connected to a second slider 18, and the upper end of the second torsion spring 16 is fixed in the support column 3;
[0039] And, combined with Figure 3 , Figure 4 The positions of the first slider 17 and the second slider 18 in the cavity 14 are respectively provided with a first outer semicircular groove 31 and a second outer semicircular groove 32, and the first slider 17 and the second slider 18 can slide and rotate in the first outer semicircular groove 31 and the second outer semicircular groove 32 respectively; the positions of the support rod 6 corresponding to the first slider 17 and the second slider 18 are respectively provided with a first inner semicircular groove 63 and a second inner semicircular groove 64, and the first slider 17 and the second slider 18 can slide and rotate in the first inner semicircular groove 63 and the second inner semicircular groove 64 respectively; the first outer semicircular groove 31 and the first inner semicircular groove 63 are respectively symmetrical with the second outer semicircular groove 32 and the second inner semicircular groove 64 about the axis center of the support rod 6.
[0040] In this embodiment, when the user pulls the support rod 6, the bent rod rotates counterclockwise, and the first inner semicircular groove 63 limits the first slider 17, thereby driving the first slider 17 to rotate counterclockwise (refer to Figure 3 ), thereby tightening the first torsion spring 15, thereby generating resistance to pulling, at this time, the second slider 18 can move along the second inner semicircular slide groove 64, and the second torsion spring 16 does not work; when the supporting rod 6 is pushed, the bent rod will rotate clockwise, and the second inner semicircular slide groove 64 limits the second slider 18, thereby driving the second slider 18 to rotate clockwise (refer to Figure 4 ), thereby tightening the second torsion spring 16, thereby generating resistance to the push. At this time, the first slider 17 can move along the first inner semicircular sliding groove 63, and the first torsion spring 15 does not work.
[0041] Combination Figure 1 , Figure 7 The running mechanism includes an active roller 81 rotatably arranged between the parallel ends of the base frame 1, a driven roller 82 is rotatably arranged at one end between the parallel ends of the base frame 1 away from the active roller 81, a running belt 8 is sleeved on the outer circumferential surface of the active roller 81 and the driven roller 82, a support plate 9 for supporting the user is arranged between the upper and lower surfaces of the running belt 8, the upper surface of the support plate 9 contacts the upper surface of the running belt 8, fixing parts 91 are fixedly arranged on both side surfaces of the support plate 9, and a mounting hole is opened on the side of the parallel end of the base frame 1 close to the fixing part 91, and the fixing part 91 can be installed in the mounting hole to fix the position of the support plate 9.
[0042] In addition, a transmission wheel 10 is fixedly installed on one side of the active roller 81, and a motor 12 is fixedly installed on the parallel end of the base frame 1. A transmission belt 11 is connected between the output end of the motor 12 and the transmission wheel 10. The motor 12 drives the transmission wheel 10 to rotate through the transmission belt 11, thereby driving the active roller 81, and then the running belt 8 rotates.
[0043] Combination Figure 1 In order to facilitate users to place mobile phones or water cups, a placement plate 4 is fixedly provided on the top of the support column 3, and a support rod 6 passes through the placement plate 4 and is rotatably connected to the placement plate 4.
[0044] Combination Figure 1 In order to facilitate the user to support in different postures, a handle 5 is fixedly provided on the upper end of the support column 3 away from the placement plate 4.
[0045] Combination Figure 1 In order to prevent the running mechanism from being disturbed by debris during operation, a protective shell 2 is fixedly installed on the upper surface of the base frame 1. The protective shell 2 can prevent debris from falling into the running mechanism, thereby protecting the motor 12 and the rotating part.
[0046] The working principle and use process of the utility model are as follows: during use, when the user needs to exercise his arms, the threaded sleeve 13 is rotated to disengage the threaded sleeve 13 from the other supporting rod 6, thereby opening the limit of the two supporting rods 6. The supporting rod 6 is located inside the cavity 14 of the support column 3 and is connected to a rotation resistance mechanism. The rotation resistance mechanism can apply resistance to the movement of the supporting rod 6. When the supporting rod 6 is pulled, the first inner semicircular groove 63 limits the first slider 17, thereby tightening the first torsion spring 15, thereby generating resistance to pulling. When the supporting rod 6 is pushed, the second inner semicircular groove 64 limits the second slider 18, thereby tightening the second torsion spring 16, thereby generating resistance to pushing, so as to achieve the exercise effect on the user's arm.
[0047] When the user needs to run or walk for exercise, the motor 12 drives the active roller 81, thereby driving the treadmill 8 to rotate. When the user is running, the support rod 6 or the handle 5 in the limited state can be used to stabilize the body to avoid falling. Running or walking exercises can increase oxygen intake, help stimulate brain cells, and prevent brain cell degeneration.
[0048] When the user is doing walking exercise or arm exercise, the user can also use the hand exercise mechanism 7 to promote blood circulation in the hands by grasping the two gripping pieces 73 to stretch and clench the fists, and massage the acupuncture points of the hands through the protrusions 731 to stimulate the cerebral cortex and maintain the vitality of the nervous system.
[0049] In summary, the anti-Alzheimer's disease exercise device, by arranging the hand exercise mechanism 7 and the rotation resistance structure on the support rod 6, can realize hand exercise and arm exercise through the support rod 6, can exercise the arm and hand at the same time, and is more convenient to use; by arranging the gripping piece 73 with the protrusion 731, it can stimulate the hand acupoints while performing stretching and fisting exercises, thereby stimulating the cerebral cortex nerves and promoting the blood circulation of the hand; by arranging the first torsion spring 15 and the second torsion spring 16 that work independently, and making the torsion spring only tightened during operation, the service life of the torsion spring is increased and the failure rate of the device is reduced; by arranging the running mechanism and increasing the exercise methods, it can increase the user's oxygen intake, help stimulate brain cells, and improve the use effect of the device.
[0050] It should be noted that, in this article, terms such as "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.
[0051] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. An anti-alzheimer's exercise device, comprising a base frame (1), characterized in that: Also includes: The base frame (1) comprises parallel ends on both sides and connecting ends connected between the parallel ends, and support columns (3) are fixedly arranged on the upper surfaces of the parallel ends on both sides of the base frame (1), and a supporting rod (6) is arranged at the upper end of the support column (3); The support rod (6) comprises a straight rod and a curved rod, one end of the curved rod is connected to the support column (3), a connecting rod (62) is fixedly connected between the curved rod and the straight rod, and a hand exercise mechanism (7) is provided on the outer circumference of the connecting rod (62) for rotation; A rotation resistance mechanism, the rotation resistance mechanism being arranged in the support column (3), and the rotation resistance mechanism being capable of applying circumferential resistance to the bending rod; A running mechanism is provided between the parallel ends of the base frame (1), and the running mechanism enables an elderly person to perform running exercises.
2. The anti-alzheimer's training device according to claim 1, characterized in that: A threaded sleeve (13) is sleeved on the outer circumference of one end of the straight rod opposite to the supporting rod (6); a connecting thread (61) is fixedly provided on the outer circumferential surface of the straight rod corresponding to the threaded sleeve (13); the threaded sleeve (13) can be rotated along the connecting thread (61) to extend to another straight rod, and the connecting thread (61) can prevent the threaded sleeve (13) from being separated from the straight rod.
3. The anti-alzheimer's training device according to claim 1, characterized in that: The hand exercise mechanism (7) comprises a first rotating plate (71) and a second rotating plate (72), wherein the middle parts of the first rotating plate (71) and the second rotating plate (72) are rotatably connected to a connecting rod (62), and gripping members (73) are rotatably provided on both sides between the first rotating plate (71) and the second rotating plate (72), and the gripping members (73) can rotate around the connecting rod (62).
4. The anti-alzheimer's training device according to claim 3, characterized in that: The outer surface of the gripping member (73) is fixedly provided with a protrusion (731), and the protrusion (731) can stimulate the hand.
5. The anti-alzheimer's training device according to claim 1, characterized in that: The upper end of the support column (3) is provided with a cavity (14), the lower end of the bent rod is located in the cavity (14), and the bottom end of the bent rod is rotatably connected to the support column (3); The rotation resistance mechanism comprises a first torsion spring (15) and a second torsion spring (16) arranged in the cavity (14), and the first torsion spring (15) and the second torsion spring (16) have the same rotation direction, the first torsion spring (15) and the second torsion spring (16) are sleeved on the outer peripheral surface of the bent rod, the upper end of the first torsion spring (15) is fixedly connected to a first slider (17), the lower end of the first torsion spring (15) is fixed in the support column (3), the lower end of the second torsion spring (16) is fixedly connected to a second slider (18), and the upper end of the second torsion spring (16) is fixed in the support column (3); The cavity (14) is provided with a first outer semicircular groove (31) and a second outer semicircular groove (32) at positions corresponding to the first slider (17) and the second slider (18), and the first slider (17) and the second slider (18) can slide and rotate in the first outer semicircular groove (31) and the second outer semicircular groove (32), respectively; the support rod (6) is provided with a first inner semicircular groove (63) and a second inner semicircular groove (64) at positions corresponding to the first slider (17) and the second slider (18), and the first slider (17) and the second slider (18) can slide and rotate in the first inner semicircular groove (63) and the second inner semicircular groove (64), respectively; The first outer semicircular sliding groove (31) and the first inner semicircular sliding groove (63) are respectively symmetrical with the second outer semicircular sliding groove (32) and the second inner semicircular sliding groove (64) about the axis center of the support rod (6).
6. The anti-alzheimer's training device according to claim 1, characterized in that: The running mechanism comprises a driving roller (81) rotatably arranged between the parallel ends of the base frame (1); a driven roller (82) rotatably arranged at one end of the parallel ends of the base frame (1) away from the driving roller (81); a running belt (8) is sleeved on the outer circumferential surfaces of the driving roller (81) and the driven roller (82); a support plate (9) is arranged between the upper and lower surfaces of the running belt (8); the upper surface of the support plate (9) contacts the upper surface of the running belt (8); fixing members (91) are fixedly arranged on both side surfaces of the support plate (9); a mounting hole is provided on the side edge of the parallel ends of the base frame (1) close to the fixing member (91); the fixing member (91) can be installed in the mounting hole; A transmission wheel (10) is fixedly mounted on one side of the active roller (81), a motor (12) is fixedly mounted on the parallel end of the base frame (1), and a transmission belt (11) is connected between the output end of the motor (12) and the transmission wheel (10).
7. The anti-alzheimer's training device according to claim 1, characterized in that: A placement plate (4) is fixedly provided at the top end of the support column (3), and the support rod (6) passes through the placement plate (4).
8. The anti-alzheimer's training device according to claim 7, characterized in that: A handle (5) is fixedly provided on a side of the upper end of the support column (3) away from the placement plate (4).
9. The anti-alzheimer's training device according to claim 1, characterized in that: A protective shell (2) is fixedly mounted on the upper surface of the base frame (1), and the protective shell (2) can prevent debris from falling into the running mechanism.