Cam type door closer

A cam type door closer includes a housing, a first piston set mounted in one side of the housing, a second piston set mounted in the other side of the housing, which includes a second piston movably mounted in a shaft hole of a first piston of the first piston set, a gap compensation device mounted in the second piston, a second spring having one end thereof stopped against the second piston and a security and sealing cap mounted in the housing to stop the other end of the second spring, and a drive shaft assembly rotatably mounted in a longitudinal passage of housing, which includes a shaft and an eccentric cam mounted on the shaft with one side thereof stopped against a roller of the first piston set and an opposite side thereof stopped against the second piston.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a door closer, in particular to a cam type door closer capable of compensating for a gap, which can stabilize the closing speed of the door by a compensation design of the piston during the closing process.

2. Description of the Related Art

In Taiwan Patent No. 1495780, a conventional door closer is used to assist the door to be slowly and automatically closed after being opened, thereby maintaining the stability and closed state of the indoor environment.

However, for a long time, conventional door closers mostly emphasize the change of the closing speed, the design that can adjust the strength of the damping resistance to conform to the traveling speed when the door is closed, or the placement a fireproof design in the valve body. If it encounters a sudden fire, the fireproof design can automatically start to close the door to prevent the fire from spreading further to reduce the danger range. With the development and improvement of the door closer manufacturers over the years, the convenience and safety of the above-mentioned door closers have also improved. In other words, the practicality and safety of today's door closers are mature and stable. However, the pistons of conventional door closers cannot provide a fixed axis (or eccentric cam) with a timely resistance between 90 degrees and 75 degrees. Therefore, when the door is turned from the open state to the closed state, the door will have a non-resistance or uncontrolled condition between 90 degrees and 75 degrees, which may cause the door closer to be unstable or even cause internal components to be damaged. Therefore, conventional door closers are still not satisfactory in function, and need to be improved.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a cam type door closer, which has the effect of controlling the closing speed of the glass door in the whole process and has the advantage of positioning the glass door at a predetermined pivot angle.

To achieve this and other objects of the present invention, a cam type door closer comprises a housing, a first piston set, a second piston set, and a drive shaft assembly. The housing comprises an axial passage and a longitudinal passage in communication with the axial passage. The axial passage extends perpendicular to the longitudinal passage and runs through two opposite sides of the housing. The first piston set is mounted in the axial passage of the housing, comprising a first piston, a roller, a plug pin, a first spring and a first sealing cap. The first piston comprises an open chamber, a shaft hole and an elongated slot respectively disposed in communication with each other. The open chamber is located in a middle part of the first piston. The shaft hole is located in a distal end of the first piston. The elongated slot is disposed above the open chamber. The first spring is mounted in the axial passage of the housing with one end thereof stopped against the first piston and an opposite end thereof stopped against the first sealing cap. The first sealing cap is mounted in the housing to seal one end of the axial passage. The second piston set is mounted in the axial passage of the housing, comprising a second piston, a gap compensation device, a second spring and a second sealing cap. The second piston is movably mounted in the shaft hole of the first piston, comprising a large diameter passage and a small diameter passage in communication with each other. The gap compensation device is mounted in the large diameter passage of the second piston. The second spring is mounted in the axial passage of the housing with one end thereof stopped against the second piston and an opposite end thereof stopped against the second sealing cap. The second sealing cap is mounted in the housing to seal an opposite end of the axial passage. The drive shaft assembly is rotatably inserted into the longitudinal passage of the housing, comprising a shaft and an eccentric cam. The eccentric cam is located on the shaft with one side thereof stopped against the roller of the first piston set and an opposite side thereof stopped against the second piston of the second piston set.

Preferably, the housing further comprises a recess located above the longitudinal passage. The shaft comprises a latching segment, a connecting segment and a transition segment between the latching segment and the connecting segment. The eccentric cam is mounted on the shaft between the transition segment and the connecting segment within the open chamber of the first piston. The connecting segment of the shaft is inserted through the elongated slot of the first piston into the recess of the housing.

Preferably, the drive shaft assembly further comprises an upper bushing, a gasket and a lower bushing set. The upper bushing and the gasket are mounted in said recess of the housing. The connecting segment of the shaft is inserted into the upper bushing. The lower bushing set is mounted on the transition segment of the shaft to enhance the pivoting smoothness of the drive shaft assembly.

Preferably, the gap compensation device of the second piston set comprises a locating ring, a sleeve, a plug, an elastic member and a locating pin. The locating ring is threaded into the large diameter passage of the second piston. The sleeve comprises a sleeve body and a flange at a distal end of the sleeve body. The sleeve body is inserted into the locating ring. The flange is stopped at an end edge of the locating ring. The sleeve body of the sleeve comprises an accommodating space and a small passage coaxially communicated with each other. The plug and the elastic member are sequentially mounted in the accommodating space of the sleeve body. The plug has one end thereof facing toward the small passage of the sleeve body and an opposite end thereof stopped against the elastic member. The locating pin is inserted into the sleeve body to pass through the accommodating space for stopping the elastic member. It is used to adjust the fuel supply of the hydraulic piston so as to improve the opening and closing quality and control the closing speed.

Preferably, the eccentric cam comprises two positioning grooves. One positioning groove is adapted for stopping against the roller of the first piston set when the housing is biased to a first predetermined pivot angle. The other positioning groove is adapted for stopping against the second piston of the second piston set when the housing is biased to a second predetermined pivot angle. In this way, the user can open the door to a predetermined angle, and at the same time, can control the speed of closing the door to increase the practicality of the cam type door closer.

Preferably, the eccentric cam comprises a concave arc portion adapted for stopping against the second piston of the second piston set when the housing is biased to a third predetermined pivot angle.

Preferably, the cam type door closer further comprises a locating block. The locating block comprises a mounting plate, a plurality of adjusting members and an adjustment plate. The mounting plate is affixed to the floor. The mounting plate comprises an accommodation chamber, and a plurality of adjusting holes on a peripheral wall thereof in communication with the accommodation chamber. The adjusting members are respectively movably mounted in the adjusting holes. The adjustment plate is mounted in the accommodation chamber of the mounting plate and connected to the shaft of the drive shaft assembly and stoppable by the adjusting members to move relative to the mounting plate in adjusting the deviation of the door so that the door can be accurately closed.

Therefore, when the user closes the glass door, the first spring of the first piston set and the second spring of the second piston set will each provide a moderate pressure to the first piston and the second piston against the roller and the second piston and provides resistance to the eccentric cam of the drive shaft assembly in the whole door closing process, so that the closing speed of the glass door can be controlled at all times, which can reduce the damage of the internal components of the door closer.

DETAILED DESCRIPTION OF THE INVENTION

The applicant first describes here, throughout the specification, including the preferred embodiment described below and the claims of the scope of the present application, the nouns relating to directionality are based on the direction in the schema. In the following preferred embodiment and the drawings, the same reference numerals are used to refer to the same or similar elements or structural features thereof.

Referring toFIGS. 1-3, a cam type door closer10in accordance with the present invention is shown. The cam type door closer10comprises a housing20, a first piston set30, a second piston set40, a drive shaft assembly50and a locating block60.

The housing20is an elongated member, having an axial passage21, a longitudinal passage23and a recess25, which are connected to each other. The axial passage21is perpendicular to the longitudinal passage23. The axial passage21runs through two opposite sides of the housing20. The recess25is located above the longitudinal passage23.

The first piston set30is located in one side of the axial passage21of the housing20, comprising a first piston31, a roller32, a plug pin33, a first spring34and a first sealing cap35. The first piston is provided with an open chamber311, a shaft hole312and an elongated slot313, which are connected to each other. The open chamber311is located in the middle of the first piston31. The shaft hole312is at the end of the first piston31. The elongated slot313is located above the open chamber311. The first spring34is mounted in the axial passage21of the housing20with one end thereof stopped against the first piston31and an opposite end thereof stopped against the first sealing cap35. The first sealing cap35is mounted in the housing20to seal one end of the axial passage21.

The second piston set40is located in an opposite side of the axial passage21of the housing20, comprising a second piston41, a gap compensation device42, a second spring43and a second sealing cap44. The second piston41is movably mounted in the shaft hole312of the first piston31. The second piston41is provided with a large diameter passage411and a small diameter passage412, which are connected to each other. The gap compensation device42is mounted in the large diameter passage411of the second piston41. The second spring43is mounted in the axial passage21of the housing20with one end thereof stopped against the second piston41, and an opposite end thereof stopped against the second sealing cap44. The second sealing cap44is mounted in the housing20to seal the opposite end of the axial passage21. More specifically, the gap compensation device42of the second piston set40comprises a locating ring421, a sleeve422, a plug423, an elastic member424and a locating pin425. The locating ring421is threaded into the large diameter passage411of the second piston41. The sleeve422has a sleeve body426and a flange427at one end of the sleeve body426. The sleeve body426is inserted through the locating ring421. The flange427is stopped at an end edge of the locating ring421. The sleeve body426of the sleeve422is provided with an accommodating space428and a small passage429in coaxial communication relationship. The plug423and the elastic member424are sequentially disposed on the accommodating space428of the sleeve body426. The plug423has one end thereof facing toward the small passage429of the sleeve body426, and an opposite end thereof stopped against the elastic member424. The locating pin425is placed on the sleeve body426and passes through the accommodating space428to abut the elastic member424.

The drive shaft assembly50is rotatably inserted through the longitudinal passage23of the housing20, comprising a shaft51, an eccentric cam52, an upper bushing53, a gasket54and a lower bushing set55. The shaft51has a latching segment511, a connecting segment513and a transition segment515between the latching segment511and the connecting segment513. The eccentric cam52is located between the transition segment515and connecting segment513of the shaft51within the open chamber311of the first piston31. Further, the eccentric cam52is a symmetrical structure, having a positioning groove521at each of two opposite sides thereof and a concave arc portion523between the two positioning groove521. When the housing20is turned to a first predetermined pivot angle (the door is opened 90 degrees to the left as shown inFIG. 4), the roller32of the first piston set30is positioned in one positioning groove521. When the housing20is turned to a second predetermined pivot angle (the door is opened 82.6 degrees or 75 degrees to the left as shown inFIG. 5orFIG. 6), the second piston41of the second piston set40is positioned in the other positioning groove421. When the housing20is turned to a third predetermined pivot angle (the door gradually changes from 45 degrees to 0 degrees as shown inFIG. 7andFIG. 8), the second piston41of the second piston set40is stopped at the concave arc portion523. The upper bushing53and the gasket54are mounted in the recess25of the housing20. The connecting segment513of the shaft51is inserted through the elongated slot313of the first piston31into the inside of the upper bushing53. The lower bushing set55is mounted on the transition segment515of the shaft51. The eccentric cam52has one side thereof stopped against the roller32of the first piston set30, and the other side thereof stopped against the second piston41of the second piston set40.

The locating block60comprises a mounting plate61, a plurality of adjusting members (not shown) and an adjustment plate62. The mounting plate61is fixed on the floor and provided with an accommodation chamber611, and a plurality of adjusting holes612are formed on the outer peripheral surface thereof to communicate with the accommodation chamber611. Each adjusting member is movably mounted in one respective adjusting hole612. The adjustment plate62is mounted in the accommodation chamber611of the mounting plate61and connected with the latching segment511of the shaft51of the drive shaft assembly50and can be moved relative to the mounting plate61by the abutment of the adjusting members.

Please refer toFIG. 4toFIG. 8.FIG. 4shows that when the glass door is opened 90 degrees to the left, the roller32of the first piston set30is forced by the first spring34to push the first piston31into abutment against the positioning groove521of the eccentric cam52, and thus, the glass door is positioned at an open position of 90 degrees. When the user performs the door closing action, as shown inFIG. 5andFIG. 6, the glass door is opened to 82.5 degrees and 75 degrees to the left, and the roller32will gradually disengage from the positioning of the positioning groove521. In order to prevent the glass door from closing quickly at this stage, the second piston41of the second piston set40will be pushed by the second spring43and will protrude into the shaft hole312of the first piston31. At the same time, the second piston41of the second piston set40will continuously apply pressure to the eccentric cam52to slow down the door closing speed of 90 degrees to 75 degrees. More precisely, the second piston41is stopped against the positioning groove521of the eccentric cam52so as to control the closing speed of the pivoting angle of the glass door from 90 degrees to 75 degrees. As shown inFIG. 7, when the glass door is gradually pivoted to 45 degrees, the roller32and the second piston41are respectively separated from the respective positioning grooves521. Since the roller32and the second piston41are simultaneously pressed to the eccentric cam52at this time, the closing speed of the glass door can be effectively controlled before the glass door is gradually pivoted from 75 degrees to 0 degrees. Finally, when the glass door is pivoted to 0 degrees as shown inFIG. 8, the second piston41is stopped against the concave arc portion523of the eccentric cam52and the roller32is stopped at the top side of the eccentric cam52opposite to the concave arc portion523, allowing the glass door to be stably positioned at 0 degrees.

In summary, when the user closes the glass door, the first spring34of the first piston set30and the second spring43of the second piston set40will provide moderate pressure to the first piston31and the second piston41respectively, enabling the roller32and the second piston41to provide resistance to the eccentric cam52of the drive shaft assembly50in the whole door closing process, so that the door closing speed of the glass door can be controlled at all times. This can effectively overcome the damage of the internal components of the door closer when the glass door is pivoted from 90 degrees to 75 degrees.