Lat pulldown fitness device

Patent metadata

Field	Value
Publication number	US-9744404-B2
Application number	US-201414561260-A
Country	US
Kind code	B2
Filing date	Dec 5, 2014
Priority date	Sep 5, 2014
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

A lat pulldown fitness device includes a base, a magnetorheological fluid (MRF) resistance provider, a motor, a gear train, pulleys, a cable assembly, a pulldown bar and a controller. The MRF resistance provider and the motor provide a resistance functioning as a load weight of pulling down the pulldown bar. The controller controls a current input to the MRF resistance provider to change the strength of the resistance generated from the MRF resistance provider. During a workout, the resistance provided by the lat pulldown fitness device is changeable precisely, conveniently, and quickly. Unlike its conventional counterparts which require bumper plates for use as weights, the lat pulldown fitness device is not limited to weight adjustment based on unit bumper plate but features plenty choices and controllable resolution in terms of strength of training. The MRF resistance provider is more compact and lightweight than its conventional counterparts.

First claim

What is claimed is:

1. A lat pulldown fitness device, comprising:
a base, wherein a seat portion, a footrest portion, and a support frame are disposed on the base, with the footrest portion disposed between the seat portion and the support frame;
a magnetorheological fluid (MRF) resistance provider disposed on the base and provided in form of a magnetorheological fluid (MRF) damper including a magnetic field generating portion, a magnetically permeable external roller, and a shaft, with the shaft coupled to the magnetic field generating portion and received in the magnetically permeable external roller, wherein two ends of the shaft stick out of the magnetically permeable external roller, and one of the two ends connects to a spindle of a motor, wherein the magnetically permeable external roller rotates relative to the shaft and the magnetic field generating portion, wherein a magnetorheological fluid (MRF) is filled between the magnetically permeable external roller and the magnetic field generating portion, wherein the magnetic field generating portion generates a magnetic field under which the MRF generates an anti-shear stress between the magnetically permeable external roller and the magnetic field generating portion rotating relative to the magnetically permeable external roller;
a gear train disposed on the base and including a chain, a large gear, and a small gear, with the small gear coupled to the magnetically permeable external roller, wherein the chain connects the large gear and the small gear;
a plurality of pulleys disposed on the support frame;
a cable assembly disposed on the base and including a reel and a cable, with the reel coupled to the large gear, wherein a portion of the cable winds around the reel and another portion of the cable straddles the pulleys;
a pulldown bar disposed at an end of the cable and hanging above the seat portion; and
a controller electrically connected to the MRF resistance provider and the motor, wherein the controller controls a strength of a magnetic field generated from the magnetic field generating portion and controllably drives the motor, so as to control a weight provided by the MRF resistance provider and the motor to pull the cable downward.

2. The lat pulldown fitness device of claim 1 , further comprising a display screen electrically connected to the controller.

3. The lat pulldown fitness device of claim 2 , further comprising a reflection mirror disposed upright on the base and positioned between the footrest portion and the gear train.

4. The lat pulldown fitness device of claim 3 , wherein the display screen is a touchscreen mounted on the reflection mirror.

5. The lat pulldown fitness device of claim 4 , further comprising a chip reader disposed on the support frame and electrically connected to the controller.

6. The lat pulldown fitness device of claim 1 , wherein the magnetic field generating portion comprises a magnetically permeable body, even-numbered magnetic poles, even-numbered magnetically permeable coils, even-numbered spacers, and two first covers, wherein the magnetic poles are spaced apart and disposed circumferentially on the magnetically permeable body, with each said magnetically permeable coil disposed around a corresponding one of the magnetic poles, the spacers each adjoining two magnetic poles to hermetically seal a space between the two magnetic poles, the first covers flanking the magnetically permeable body, the magnetic poles, and the spacers so as for the magnetically permeable coils to be hermetically sealed within a space defined jointly by the first covers, the magnetic poles, and the spacers, with the shaft coupled to the magnetically permeable body and sticking out of the first covers and the magnetically permeable external roller.

7. The lat pulldown fitness device of claim 6 , wherein currents in the magnetically permeable coils of two adjacent magnetic poles run in opposite directions.

8. The lat pulldown fitness device of claim 7 , wherein the magnetic poles each comprise a cylindrical magnetically permeable block and a curved magnetically permeable head, with the magnetically permeable coil disposed around the cylindrical magnetically permeable block, with each said spacer being curved, plate-like and disposed between two adjacent curved magnetically permeable heads, such that the magnetic field generating portion takes on a cylindrical shape upon completion of assembly.

9. The lat pulldown fitness device of claim 8 , wherein the magnetic field generating portion comprises two first washers each disposed between the first covers, the curved magnetically permeable heads of the magnetic poles, and the spacers, respectively.

10. The lat pulldown fitness device of claim 1 , wherein the magnetically permeable external roller comprises an external cylinder, two second covers, and two second washers, with the second covers flanking the external cylinder, and with the second washers each disposed between the second covers and the external cylinder.

Assignees

• Univ Nat Taipei Technology

Inventors

• Shiao Yaojung
• Lin Ting-Yen

Classifications

• A63B21/00845

  using electrorheological or magnetorheological fluids · CPC title

• A63B71/0622

  Visual, audio or audio-visual systems for entertaining, instructing or motivating the user · CPC title

• A63B23/0233

  Muscles of the back, e.g. by an extension of the body against a resistance, reverse crunch · CPC title

• A63B2071/0638

  Displaying moving images of recorded environment, e.g. virtual environment · CPC title

• A63B2225/12

  with mirrors · CPC title